EARTH SURFACE PROCESSES AND LANDFORMS, Issue 9 2001
D. J. Oostwoud Wijdenes
Abstract A three year monitoring programme of gully-head retreat was established to assess the significance of sediment production in a drainage network that expanded rapidly by gully-head erosion on the low-angled alluvio-lacustrine Njemps Flats in semi-arid Baringo District, Kenya. This paper discusses the factors controlling the large observed spatial and temporal variation in gully-head retreat rates, ranging from 0 to 15 m a,1. The selected gullies differed in planform and in runoff-contributing catchment area but soil material and land use were similar. The data were analysed at event and annual timescales. The results show that at annual timescale rainfall amount appears to be a good indicator of gully-head retreat, while at storm-event timescale rainfall distribution has to be taken into account. A model is proposed, including only rainfall (P) and the number of dry days (DD) between storms: which explains 56 per cent of the variation in retreat rate of the single-headed gully of Lam1. A detailed sediment budget has been established for Lam1 and its runoff-contributing area (RCA). By measuring sediment input from the RCA, the sediment output by channelized flow and linear retreat of the gully head for nine storms, it can be seen that erosion shifts between different components of the budget depending on the duration of the dry period (DD) between storms. Sediment input from the RCA was usually the largest component for the smaller storms. The erosion of the gully head occurred as a direct effect of runoff falling over the edge (GHwaterfall) and of the indirect destabilization of the adjacent walls by the waterfall erosion and by saturation (GHmass/storage). The latter component (GHmass/storage) was usually much larger that the former (GHwaterfall). The sediment output from the gully was strongly related to the runoff volume while the linear retreat, because of its complex behaviour, was not. Overall, the results show that the annual retreat is the optimal timescale to predict retreat patterns. More detailed knowledge about relevant processes and interactions is necessary if gully-head erosion is to be included in event-based soil erosion models. Copyright © 2001 John Wiley & Sons, Ltd. [source]

INTEGRATED STUDIES ON THE FRESHNESS OF RAINBOW TROUT (ONCORHYNCHUS MYKISS WALBAUM) POSTMORTEM DURING CHILLED AND FROZEN STORAGE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2004
CARMEL C. WILLS
Rainbow trout were killed by two methods, asphyxiation and clubbing. The concentration of ATP in specimens of skeletal muscle taken immediately after death was significantly (P<0.01) higher in clubbed (4.41 ± 0.86 ,mol/g) than in asphyxiated (2.00 ± 0.69 ,mol/g) fish. The shear force (Warner-Bratzler) required to cut the muscle was higher (P<0.05) in clubbed (8.33 ± 0.61 N) than in asphyxiated (6.85 ± 0.98 N) fish. Changes in the concentration of adenine nucleotides and in shear force were measured at intervals during storage at 3C and - 30C. The K value was calculated and was found to be correlated inversely with changes in shear force, Torrymeter readings and sensory assessment. There were no significant differences in the concentrations of ATP and metabolites between muscle sites. There were no differences in shear force measurements between the locations sampled nor between muscle taken from the right and left sides of the fish. [source]

EFFECT OF SLAUGHTER METHOD ON DEGRADATION OF INTRAMUSCULAR TYPE V COLLAGEN DURING SHORT-TERM CHILLED STORAGE OF CHUB MACKEREL SCOMBER JAPONICUS

JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2002
KENJI SATO
ABSTRACT The present paper demonstrates that a nonstntggling slaughter method can delay degradation of type V collagen in meat of chub mackerel Scomber japonicus and softening of the meat during postharvest chilled storage. The fish were slaughtered by piercing a knife into nape (nonstruggling method) or by leaving on ground (struggling method) and then stored in an ice box. Sensory study revealed that the postharvest softening of the meat was moderated at 4 and 8 h by the non-struggling slaughter method in comparison with the struggling method. On the basis of the specific solubilization of type V collagen and reduced tyrosine content in it, a cleavage of the nonhelical regions (telopeptides) of the type V collagen occurred during the chilled storage in the fish slaughtered by the struggling method. The degradation of type V collagen was also slower in the meat of the fish slaughtered by the nonstruggling method, which can be directly linked to the moderation of the postharvest softening. [source]

RELATION BETWEEN THE FREE AMINO ACIDS, ANSERINE AND THE TOTAL VOLATILE BASIC NITROGEN PRODUCED IN MUSCLE OF HAKE (MERLUCCIUS MERLUCCIUS, L.) DURING ICED STORAGE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2002
CLAUDIA RUIZ-CAPILLAS
This work studied the development of free amino acids (FAAs) and dipeptide anserine as quality indices for gutted hake stored in ice for 25 days. The correlation of these compounds was determined with total volatile basic nitrogen (TVBN) which has been used as a quality index, for fish stored in ice. The most abundant free amino acids in hake muscle were found to be threonine, glycine, alanine, glutamic acid, ,-alanine methylhistidine. lysine and the dipeptide, anserine. The only hydrophobic free ammo adds which exhibit significant differences (P<0.05) throughout storage was tryptophan. moreover, this amino acid exhibited a very high correlation (r=0.951) with TVBN. A significant decrease in anserine (P<0.05) correlated with the increases in 1-methylhistidine and ,-alanine throughout storage. These changes also exhibited a very high correlation with TVBN. Therefore, 1-methylhistidine, ,-alanine anserine and tryptophan could be used as quality parameters for hake stored in ice. [source]

PROTEOLYSIS IN SALMON (SALMO SALAR) DURING COLD STORAGE; EFFECTS OF STORAGE TIME AND SMOKING PROCESS

JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2001
KAREN ENGVANG LUND
ABSTRACT Changes in free amino acids (FAAs), small peptides and myofibrillar proteins were investigated in salmon (Salmo salar) muscle stored at OC for up to 23 days and after the stored salmon was smoked. Storage time and smoking process did not increase the formation of FAAs and small peptides indicating low exopeptidase activity. During storage, SDS PAGE analysis of myofibrils showed an increase in density of bands at 16, 37, 60, 64, 67, 76 and 130 kDa, a decrease of a 32 kDa band and the appearance of four new bands of 30, 90, 95 and 113 kDa. These results indicate proteolytic degradation. A little change of myosin and no change of ,-actinin and actin were observed. The smoking process itself enhances the intensity of bands, but does not change the pattern markedly except for the appearance of a 25 and 70 kDa band. Degradation pattern after smoking was not affected by storage time. [source]

THE EFFECT OF ENZYMATIC MASH TREATMENT, PRESSING, CENTRIFUGATION, HOMOGENIZATION, DEAERATION, STERILIZATION AND STORAGE ON CARROT JUICE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2007
HONGMEI LIAO
ABSTRACT The enzyme preparation Pectinex Smash XXL was employed to macerate the carrot pulp, the effect of enzymatic mash treatment (EMT), pressing, centrifugation, homogenization, deaeration, sterilization and storage on carrot juice was investigated. As compared with the control sample, an increase of juice yield, total soluble solid (TSS) and carotenoids in carrot juice was close to 20%, 1% and 26 mg/kg, respectively, after EMT. The EMT also increased the color parameters CIEL*, a*and C*values in carrot juice. However, it significantly decreased the viscosity from 2.54 to 2.09 mPa·s. The centrifugation resulted in a significant decline in turbidity from 240.33 to 187.33 NTU and a significant increase in the color parameters in carrot juice. After homogenization, the turbidity and the carotenoids in carrot juice were significantly reduced from 187.33 to 161.67 NTU and from 61.87 to 58.76 mg/kg, respectively. The turbidity and carotenoids in carrot juice decreased during storage, and all the color parameters had a closer relationship with storage temperature and time; higher storage temperature and longer storage time caused greater loss of color. [source]

STABILITY OF ANTHOCYANINS, PHENOLS AND FREE RADICAL SCAVENGING ACTIVITY THROUGH SUGAR ADDITION DURING FROZEN STORAGE OF BLACKBERRIES

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2009
MIRELA KOPJAR
ABSTRACT Influence of sugar and mixtures of sugar on color retention of two varieties of blackberries, Thornfree and Cacanska bestrna, were investigated during storage at ,18C for 12 months. After harvest, blackberries were coated with sugars (sucrose, fructose and glucose) and different sugar (sucrose + fructose + glucose, fructose + glucose, fructose + sucrose) mixtures. Anthocynin content, total phenol content and free radical scavenging activity of prepared samples were evaluated. Ratio of fruit : sugar was 1:1. The highest anthocyanin retention was in blackberry samples with glucose addition and the lowest in samples with sucrose addition, in both cultivars. Blackberry samples with sucrose addition had even lower retention than samples without sugar addition. Samples with an addition of other sugars had higher retention of anthocyanin than samples stored without sugars. PRACTICAL APPLICATION Possibility of phenols retention of blackberries due to sugar addition, during cold storage was investigated. Results showed that glucose had the most positive effect on anthocyanins retention as well as total phenolic compounds content. For that reason, certain amount of sucrose in fruit preserves can be replaced by addition of glucose, and for that reason retention of phenolic compounds can be higher and, as could be expected, more effective against oxidative stress in human body due to intake of product formulation with glucose. [source]

THE EFFECT OF REFRIGERATED STORAGE ON SENSORY PROFILE AND PHYSICAL-CHEMICAL CHARACTERISTICS OF MINIMALLY PASTEURIZED ORANGE JUICE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2009
TATIANA BEATRIS TRIBESS
ABSTRACT Minimal pasteurization of orange juice (OJ) consists of using minimum holding time and temperature to ensure partial inactivation of pectin methylesterase (PME). This process produces juice with preserved sensory attributes and has a better acceptance by consumers when compared with commercially pasteurized OJ. Sensory profile and physical-chemical characteristics of minimally processed OJ was determined, during refrigerated storage, for two OJ blends with different pH values and the same level of PME thermal inactivation. A selected and trained sensorial panel (n = 16) performed sensory analysis, based on a quantitative descriptive analysis, twice a week for 30 days, evaluating the attributes of appearance (suspended particles and color intensity), odor (natural orange and fermented orange) and flavor (orange characteristic, fermented orange, acid and bitter taste). Storage presented great effect on OJ sensory profile; however, it was not noticeable on physical-chemical characteristics. PRACTICAL APPLICATIONS Minimal pasteurization of orange juice (OJ) consists of using minimum holding time and temperature to ensure partial inactivation of pectin methylesterase. This process produces juice with longer shelf life than fresh squeezed orange juice, preserved sensory attributes and better acceptance by consumers when compared with commercially pasteurized OJ. This study can contribute for quality evaluation of minimally pasteurized OJ under refrigeration. [source]

THE EFFECT OF AIR-DRYING, FREEZE-DRYING AND STORAGE ON THE QUALITY AND ANTIOXIDANT ACTIVITY OF SOME SELECTED BERRIES

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2009
MAGDALENA MICHALCZYK
ABSTRACT The aim of this study was to analyze the effects of air-drying and freeze-drying and subsequent storage of dried products on the content of polyphenols, anthocyanins and the antioxidant properties of selected berry fruits. The material was raspberry (Rubus ideaus L.), strawberry (Fragaria ananassa Duch) and bilberry (Vaccinum myrtillus). Despite exposure to atmospheric oxygen, the stored freeze-dried fruit retained the properties of the raw material better than the air-dried product. In the case of the latter, there were considerable differences in the retention of total polyphenolic and anthocyanin content as well as antioxidant properties in the three fruit species examined. In particular, bilberry maintained a high polyphenol and anthocyanin content and high antioxidant potential despite the greatest losses of these compounds. PRACTICAL APPLICATIONS Consumer demand for food with health-promoting qualities is increasing. The food industry has intensified its efforts to provide high quality, semi-processed products that fulfil this requirement. The results presented in this work indicate that even after long-term storage and despite exposure to atmospheric oxygen, freeze-dried berries retain the antioxidant properties of the raw material to a very high degree. Therefore, lyophilisates can satisfy this particular need. Air-dried berries are much less stable during long-term storage. The dynamics of the changes occurring during the storage of both kinds of product are presented in detail. [source]

KINETICS OF HYDROXYMETHYLFURFURAL ACCUMULATION AND COLOR CHANGE IN HONEY DURING STORAGE IN RELATION TO MOISTURE CONTENT

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2009
L. BULUT
ABSTRACT Quality reduction in honey during storage is indicated by hydroxymethylfurfural (HMF) accumulation and darkening of color. The effects of moisture content and temperature on HMF accumulation and color change in honey during storage were investigated. HMF accumulation and color change followed first- and zero-order reaction kinetics, respectively. The moisture content affected the rate of the two degradation reactions depending on the storage temperature. Reduction in moisture content caused an increase in rate constant for HMF accumulation at 20 and 30C, but there was no significant effect of moisture content at 40C. Rate constants for change in lightness and total color change values increased with increasing moisture content at 20 and 30C. The highest rate constant for change in color values was obtained at a moisture content of 18% at 40C. PRACTICAL APPLICATIONS Hydroxymethylfurfural accumulation and color change are two major quality degradations in honey during storage. This study shows that the rates of these two degradations are dependent on moisture content of honey. In addition, effect of moisture content on the rates of reactions was dependent on temperature of storage. Therefore, producers need to consider the effects of both moisture content and storage temperature in reducing quality loss in honey during storage. [source]

THE EFFECTS OF HOT SMOKING ON THE CHEMICAL COMPOSITION AND SHELF LIFE OF MEDITERRANEAN MUSSEL (MYTILUS GALLOPROVINCIALIS L. 1819) UNDER CHILLED STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2008
HÜLYA TURAN
ABSTRACT In this study, effects of boiling and hot smoking on proximate composition and shelf life of mussels stored at 4 ± 1C were investigated. Dry matter, crude protein, crude fat and crude ash levels were determined as 13.94, 10.30, 1.14 and 0.95% in fresh mussels 20.75, 13.83, 2.11, 0.77% after boiling and 39.57, 22.22, 10.04%, 6.02% after hot smoking, respectively. Trimethylamine nitrogen values in fresh, boiled and hot smoked mussels were determined as 1.13, 1.01 and 1.07 mg/100 g, respectively, and increased to 24.35 mg/100 g at 18th day of the storage period. pH value in hot smoked mussels ranged between 4.85 and 4.51 during the chilled storage. According to the results, mussels smoked by hot smoking and stored at refrigerator temperature (4 ± 1C) for 12 days can be consumed. PRACTICAL APPLICATIONS In many countries, smoking is used to obtain products that are popular for their texture and flavor. Mussels, scallops and oysters are some of the important mollusk species that are smoked and eaten in different parts of the world. In this research, the effects of hot smoking process (for 30 min at 82C) on proximate composition and shelf life of Mediterranean mussel stored at 4C was investigated. [source]

OPTIMAL COAGULANT CONCENTRATION, SOYMILK AND TOFU QUALITY AS AFFECTED BY A SHORT-TERM MODEL STORAGE OF PROTO SOYBEANS

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2008
ZHI-SHENG LIU
ABSTRACT Soybeans were adjusted to water activities (Aw) from 0.60 to 0.81, and stored at 30C for up to 3 months. At 1-month intervals, soybeans were retrieved from the storage and processed into 10.5 Brix soymilk. The optimal coagulant concentration (OCC) for making filled tofu was determined using a titration method. Other soymilk characteristics, including total solids, protein, 11 S/7 S protein ratio, phytate, titratable acidity, pH and color, were also determined. Filled tofu was prepared from each stored soybeans with the respective OCC using MgCl2 or CaCl2. With increasing Aw or storage time, the OCC decreased significantly. The decrease in OCC was significantly correlated to the difference in soymilk titratable acidity and the change in soymilk pH. Soybean storage time slightly decreased the breaking stress and apparent Young's modulus of the filled tofu, particularly the MgCl2 coagulated tofu. With increasing Aw or storage time, the lightness and yellowness intensity of both soymilk and tofu decreased, whereas their redness intensity increased. PRACTICAL APPLICATIONS Tofu and soymilk are popular soybean foods. Using optimal concentration of coagulant in soymilk is the most critical step among many steps of unit operations during tofu manufacturing for achieving high quality tofu. Improper use of coagulant can lead to product failure and therefore significant economic loss for the manufacturers. The optimal coagulant concentration varies not only with processing condition, but also with soybean materials which are affected by variety and storage conditions. Acidity, pH and food color are important quality factors to influence taste and consumer acceptance. Soybeans are subject to storage and transportation before processing. Storage length and environmental humidity are two of important factors which affect soybean quality and processing property. This study provides very important information that is useful for the soymilk and tofu manufacturers in controlling product quality through the understanding of the chemistry and processing characteristics of stored soybeans. Manufacturers can utilize the methods presented in this article to calculate the optimal coagulant concentrations to avoid product failure and to produce the best quality products. [source]

EFFECT OF PACKAGING MATERIALS ON THE QUALITY OF IRON-FORTIFIED WHOLEMEAL FLOUR DURING STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2007
N. HUMA
ABSTRACT The effect of packaging materials on the physicochemical and rheological characteristics of iron-fortified wholemeal flour (WMF) during storage was determined. WMF was fortified with three fortificants, namely ferrous sulfate (30 ppm), ferrous sulfate + ethylenediamine tetraacetic acid (EDTA) (20 + 20 ppm) and elemental iron (60 ppm). Each flour was also fortified with 1.5 ppm folic acid. Moisture, flour acidity and peroxide value increased during storage, while protein and fat contents decreased. Highest conversion of Fe2+ into Fe3+was observed in flour fortified with ferrous sulfate (2.72%), followed by that fortified with ferrous sulfate + EDTA (1.49%) and elemental iron (1.06%). Water absorption and dough viscosity of iron-fortified flours increased during storage. The flour containing ferrous sulfate was most acceptable regarding sensory characteristics, followed by samples containing ferrous sulfate + EDTA. Fortified flours were more stable during storage than unfortified. Addition of EDTA increased the stability of flours and fortificants. The fortified flours stored in polypropylene bags proved more stable than those stored in the tin boxes. PRACTICAL APPLICATIONS The main role of packaging is to protect the product during handling, distribution and storage against environmental and mechanical hazards. The success of a fortification program depends on the stability of micronutrients and food to which these are added. Chemical changes during storage badly affect chapatti making and sensory properties. Exposure of the fortificant to any factor including heat, moisture, air or light, and acid or alkaline environments during processing, packaging, distribution, or storage affects its stability. Flour containing elemental iron and ferrous sulfate with EDTA remained stable up to 42 days. The unfortified flour and flour containing ferrous sulfate remained stable for 21 days in tin boxes and 28 days in the polypropylene bags. Wheat flour milling industry would be benefited from this research if government is keen to launch iron fortification program in the country to curb iron deficiency anemia among population. [source]

ANTIOXIDATIVE AND ANTIMICROBIAL PROPERTIES OF LACTOFERRIN IN HOT-BONED GROUND PORK DURING STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2007
C.H. CHIU
ABSTRACT The effect of lactoferrin concentration on the antioxidative and antimicrobial activities of hot-boned (4,5 h after death) ground pork during storage at 4C for 9 days was examined. The total iron content increased with the addition of lactoferrin. Meat samples with added lactoferrin (40 or 80 mg/kg) had lower thiobarbituric acid reactive substances (TBARS) than controls at 3, 6 and 9 days; however, the differences in TBARS between the 40- and 80-mg lactoferrin/kg treatments were not significant. With the addition of lactoferrin (40 or 80 mg/kg), ground pork had lower (P < 0.05) total plate counts than controls at 3, 6 and 9 days of storage. However, the differences in total plate counts between the 40- and 80-mg lactoferrin/kg treatments were only significant (P < 0.05) at days 3 and 6. The addition of lactoferrin (80 mg/kg) decreased lactic acid bacterial counts at days 0, 3 and 9. The pH values of hot-boned ground pork were unaffected by the addition of lactoferrin, but slightly increased with storage time. [source]

EFFECT OF PROCESSING ON BACTERIAL POPULATION OF CUTTLE FISH AND CRAB AND DETERMINATION OF BACTERIAL SPOILAGE AND RANCIDITY DEVELOPING ON FROZEN STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2007
THAILAMBAL ANANTHA SUBRAMANIAN
ABSTRACT Processing techniques like cooking and freezing exhibited significant (P < 0.001) reduction in the bacterial load of cuttlefish, Sepia pharaonis, and marine crab, Portunus pelagicus. Raw cuttle fish had 2.4 × 107 cfu/g which on cooking reduced to 9.7 × 106 cfu/g. Freezing reduced the bacterial load further as cooked frozen product had only 9.9 × 104 cfu/g. Similarly, raw crab had 2.6 × 107 cfu/g which on cooking reduced to 6.5 × 106 cfu/g. A further reduction in bacterial load was seen after freezing as cooked frozen crab exhibited only 7.3 × 104 cfu/g. Escherichia coli and Staphylococcus aureus were present in the limit of acceptability for fish and fish products. Salmonella typhimurium and Vibrio cholerae were absent even in raw stage. Biochemical analysis performed on stored frozen products of cuttle fish and crab exhibited a significant (P , 0.05) increase in bacterial spoilage and rancidity with increasing days of storage. Total volatile base nitrogen, trimethylamine, thiobarbituric acid and free fatty acid contents in frozen products of cuttle fish and crab increased significantly with 120 days of frozen storage. [source]

QUALITY OF MODIFIED ATMOSPHERE PACKAGED "BARTLETT" PEARS AS INFLUENCED BY TIME AND TYPE OF STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2004
S.R. DRAKE
ABSTRACT Commercially mature "Bartlett" pears for this study were obtained from local commercial packing facilities. In the first year, pears were packed in modified atmosphere bags and placed in boxes or packed normally (control) with an individual paper wrap around each pear plus a polyethylene liner in the box. Boxed pears from both types of packaging were stored in regular atmosphere (RA) storage at 1C for 30 or 90 days. In the second year, pears were packed normally and stored in both RA or controlled atmosphere (CA) storage for 45 or 90 days, or packed in modified atmosphere bags and stored in RA at 1C. After 45 days, normally packed pears from both RA and CA were removed from their initial storage, placed in modified atmosphere bags and returned to RA storage for an additional 45 days. Pears stored in modified atmosphere bags were superior in quality to normally packed pears stored only in RA storage and equal in quality to pears stored in CA for periods of 90 days. The quality of pears held in modified atmosphere bags under CA conditions deteriorated after only short periods of time (<45 days). Pears in modified atmosphere bags should be stored only in RA. Little or no quality advantage was evident if use of modified atmosphere bags was delayed regardless of prior storage type. [source]

DISCOLORATION OF SUN-DRIED AND PROCESSED ELBERTA PEACHES DURING STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2003
E. JOUBERT
Discoloration of sun-dried ,Elberta' (Prunus persica) peaches during a 48 week storage period as affected by moisture content (15 and 17%) and temperature (4, 7, 10 and 20C) was investigated. In addition, the effect of rehydration to moisture contents of 20, 24 and 27% and resulphuring on the color of the processed fruit during storage for 100 days at 0 and 25C was studied. Drying fruit to 15% instead of 17% moisture content gave darker-colored fruit, and it did not improve color retention during storage. Storage at 20C decreased L* values, indicating darkening of the fruit, but the quality, correlated with chroma, was still acceptable for fruit obtained with most of the treatment combinations. Substantial losses of SO2 occurred at 20C. Rehydration and resulphuring increased chroma and hue values of the fruit. Storage of processed fruit at OC was effective in preventing discoloration, irrespective of treatment, while discoloration took place at 25C. [source]

EFFECTS OF RETORTING AND STORAGE ON LIQUID MASS TRANSFER IN CANNED SKIPJACK (KATSUWONAS PELAMIS) MUSCLE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2002
J. W. BELL
Mass loss of precooked tuna muscle during retorting and storage in cans impacts cannery yield and throughput. Changes in moisture content and mass of frozen, thawed, precooked tuna muscle chunks, canned in water, were determined after retorting and through five weeks of subsequent storage. Canned tuna pieces were retorted to equivalent lethality (Fo -value of four) for different time and temperature processes. Retorting at a lower temperature, longer time resulted in less mass loss than higher temperature, shorter time processes. Canned storage of up to five weeks had no effect on muscle mass or moisture content. [source]

QUALITY LOSS DURING TOMATO PASTE PRODUCTION VERSUS SAUCE STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2001
RADHIKA K. APAIAH
Two studies were conducted to assess the extent of quality changes in tomato processing versus storage. For the processing study, tomato juice was vacuum concentrated into paste at 68C for 300 min (LT) or 85C for 34 min (ST) and samples taken at 5,26 Brix. Reduced ascorbic acid (RAA) degraded sooner during LT than ST, but reached equivalent final concentrations. The particle size decreased and hue angle increased during LT, but not ST. The viscosity decreased more during LT than ST. There was no formation of 5-hydroxymethyl furfural (HMF.) For the storage study, commercial tomato sauce was stored at 4 to 55C for 6 months. RAA degradation and HMF formation during storage were first order with activation energies of 77 and 70 KJ/mole, respectively. The particle size decreased at all storage temperatures, viscosity decreased at 45 to 55C and hue angle increased at 37 to 55C. In general, quality loss of tomato sauce during processing was greater than during storage. [source]

EFFECT OF COMBINED UNDERWATER PROCESSING AND MILD PRECUT HEAT TREATMENT ON THE SENSORY QUALITY AND STORAGE OF FRESH-CUT CANTALOUPE MELON

JOURNAL OF FOOD QUALITY, Issue 4 2010
KAREN L. BETT-GARBER
ABSTRACT Improvement of storage quality of fresh-cut cantaloupe using a combination precut heat treatment and a modified underwater cutting treatment was determined. Eating quality was evaluated using descriptive sensory analysis, and fruit integrity was measured with respiration, cell leakage and product weight loss. Treatments included (1) control (no treatment); (2) making the first longitudinal cut underwater; (3) mild precut heat treatment in a water bath at 60C for 60 min; and (4) combination of precut heat treatment and the underwater cutting methods. Precut heating and processing underwater resulted in more intense fruity/melon flavor compared to conventional processed fresh-cut fruit. Reduced electrolyte leakage and enhanced membrane integrity were observed in all three experimental treatments, as evidenced by lower conductivity measurements. The underwater cut and combined treatments significantly reduced respiration during fresh-cut storage, reflecting less physical stress and membrane damage. Weight loss was not significantly affected by any treatment during fresh-cut storage. PRACTICAL APPLICATIONS There is a steady increase in the consumption of fresh-cut produce. To enhance the storage quality of fresh-cut cantaloupe melon, two minimal processing techniques were examined separately and combined. The methods are mild heat treatment of the whole melon at 60C for 60 min then cooling to 4C for 24 h, cutting the cantaloupe in half and removing the seeds while submerged in a calcium chloride and water solution, and the combination of the two treatments. These methods are simple and can be utilized by small or large processors to maintain sensory quality and fruit integrity during storage. [source]

EFFECT OF 1-METHYLCYCLOPROPENE ON NUTRITIONAL QUALITY AND ANTIOXIDANT ACTIVITY OF TOMATO FRUIT (SOLANUM LYCOPERSICON L.) DURING STORAGE

JOURNAL OF FOOD QUALITY, Issue 2 2010
MENG WANG
ABSTRACT The effect of 1-methylcyclopropene (1-MCP) on postharvest quality and nutritional compounds in tomato (Solanum lycopersicon Mill.) fruit during storage was determined. The green mature tomato was exposed to 1 µL/L 1-MCP for 24 h. Thereafter, the fruit were stored at 20C and 85,95% relative humidity for 20 days. The results indicated that 1-MCP treatment significantly delayed the decrease of firmness, total soluble solids, and titratable acidity, inhibited the increase of weight loss, and suppressed the rise in respiration rate and ethylene production. Moreover, 1-MCP treatment also inhibited the lycopene accumulation and chlorophyll degradation. Ascorbic acid and soluble phenolic contents in 1-MCP-treated fruit were significantly higher than those in the control fruit. 1-MCP treatment enhanced the ferric reducing antioxidant power (FRAP) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. These results suggested that 1-MCP can be used as a commercial technology due to its ability to improve nutritional value of tomato fruit as well as to delay fruit ripening. PRACTICAL APPLICATIONS Tomato fruit are often harvested at mature green stage to minimize damage during transport to market, and then allowed to ripen before or during presentation in retail outlets. A limitation to marketing of tomato fruit is the time that ripe fruit remain in an acceptable condition for consumers. 1-Methylcyclopropene (1-MCP) can extend the storage life and improve postharvest quality of tomato fruit. Recently, nutritional quality is of increasing interest to the consumers because of their potential health benefits in protecting against various diseases. However, the effects of 1-MCP on nutritional compounds and antioxidant activity of tomato fruit are still unclear and need to be more precisely determined. This study can provide information on the effect of 1-MCP treatment on postharvest quality and nutritional compounds in tomato fruit during storage. The results could be applicable to improve the quality and nutritional value of tomato fruit for commercial purpose. [source]

EFFECT OF DIRECT APPLICATIONS OF SAGE (SALVIA OFFICINALIS L.) LEAVES ON OXIDATIVE STABILITY OF SUNFLOWER OIL DURING ACCELERATED STORAGE

JOURNAL OF FOOD QUALITY, Issue 5 2009
EDA ÇALIKO
ABSTRACT In this study, various sage applications were examined on oxidative stability of sunflower oil during accelerated storage. There are three applications: (1) direct sage leaves (S); (2) deodorized sage leaves (DeS); and (3) essential oil of sage leaves. The main compounds of essential oil were identified as, -thujone (35.87%),, -thujone (14.41%), 1,8-cineol (10.59%) and camphor (10.09%). Oxidative stability of these three applications was tested by Schall Oven test at 60C applying peroxide value and conjugated dienes, and Rancimat at 110C. Whereas the highest antioxidants activity was found for 2% S followed by 0.5% S and 2% DeS, all sage treatments statistically retarded the oxidation compared with the control sample. The most appealing result was that the residue can be used as a natural antioxidants. That means the reuse of residue may decrease economic losses and health risk in comparison with synthetic antioxidants and extracts because it is completely natural and contains no residual solvent. PRACTICAL APPLICATIONS While almost all of previous studies were concentrated on the use of herb extracts, our study investigates the results of direct application of sage on oxidation. Especially with this study, we have evaluated a possible application area for sage residue leftover after the deodorization process. [source]

RHEOLOGICAL AND SENSORY QUALITY OF READY-TO-BAKE CHAPATTI DURING FROZEN STORAGE

JOURNAL OF FOOD QUALITY, Issue 4 2009
D.N. YADAV
ABSTRACT The effect of prolonged frozen storage at ,18C, on the textural and sensory properties of ready-to-bake frozen chapatti (R-BFC) was evaluated. The R-BFC samples were prepared from normal- (control) and microwave-treated (18% moisture content for 80 s) wheat grains. Results showed that the extensibility of dough and maximum load for resistance increased gradually in both the samples during frozen storage; however, the increase was lesser in the treated ones. Chapattis prepared from both R-BFC samples exhibited higher hardness, cohesiveness, chewiness and lower springiness values during frozen storage. Microwave-treated R-BFC samples were rated as better retained in color, texture and overall acceptability scores as compared with control, up to 6 months of storage at ,18C. Thiamin and riboflavin contents were monitored during frozen storage and a loss of 12.0,14.5% in thiamin and 4,6% in riboflavin after 6 months of frozen storage was recorded. PRACTICAL APPLICATIONS During frozen storage, various physical, rheological and sensory changes occur in the food products, which determine the consumer's acceptability. The results of this study will help to establish quality of the frozen chapattis with respect to texture, color and aroma which will meet the consumer's acceptance. The protocol for the storage of frozen chapattis will help the industry to deliver the product of optimum quality. [source]

EVALUATION OF MICROBIOLOGICAL, PHYSICOCHEMICAL AND SENSORY QUALITIES OF CHITOSAN TOFU DURING STORAGE

JOURNAL OF FOOD QUALITY, Issue 1 2004
MEERA KIM
ABSTRACT Tofu containing both low and high viscosity chitosan was prepared and changes in the microbiological, physicochemical and sensory properties of the tofu during storage were investigated. The colony forming units of mesophilic and psychrotrophic microorganisms in tofu containing high viscosity chitosan were markedly lower during storage than those in the control tofu as well as the tofu containing low viscosity chitosan. The pH of the tofu samples increased during storage. The L and a values of the tofu, especially the control tofu, increased during storage. In the sensory test, the roasted nutty and beany aromas of the tofu decreased during storage. Instrumental analysis of hardness and chewiness of the tofu decreased during storage. Overall preference for the tofu gradually decreased during storage, but overall preference for the tofu containing high viscosity chitosan scored higher than the other tofu samples. [source]

EFFECT OF DIFFERENT METHODS FOR APPLICATION OF AN ANTIFOG SHRINK FILM TO MAINTAIN CAULIFLOWER QUALITY DURING STORAGE

JOURNAL OF FOOD QUALITY, Issue 3 2003
J. R. DeELL
The antifog shrink film improved quality retention and cauliflower packaged using any of the four methods exhibited less weight loss than controls (unwrapped) after 23 days in storage at 0,1C or 10C. The overwrap and sealed bag treatments resulted in higher appearance ratings and less curd browning and butt discoloration after storage at 0,1C. Shrinking the film with heat and/or vacuum may have damaged the tissue, providing a more favorable environment for microorganism growth, since more decay was found on these curds. [source]

QUALITY OF ,ANJOU' PEARS AFTER DIFFERENT TYPES OF CONTROLLED ATMOSPHERE STORAGE

JOURNAL OF FOOD QUALITY, Issue 1 2001
S.R. DRAKE
ABSTRACT ,Anjou' pears (Pyrus communis, L) were subjected to seven different controlled atmosphere (CA) storage practices and stored at 1C, for 90, 150 or 210 days plus 30 days at regular air atmosphere (RA). CA storage treatment conserved pear qualities to a certain extent regardless of storage treatment. Establishment of CA conditions (2% O2 and < 1 % CO2 on warm pears (20C), prior to cooling, resulted in reduced firmness, finish and color and increased amount of scald, shrivel and physiological disorders. Pears held in CA storage (2% O2 and < 1 % CO2) for 90 days and an additional 30 days in RA storage maintained good quality. When held for longer storage periods, firmness, finish and color decreased, and scald, shrivel and physiological disorders increased. [source]

EFFECT OF THERMOPHILIC LACTIC ACID BACTERIA ON THE FATE OF ENTEROBACTER SAKAZAKII DURING PROCESSING AND STORAGE OF PLAIN YOGURT

JOURNAL OF FOOD SAFETY, Issue 2 2008
REYAD R. SHAKER
ABSTRACT Survival and growth of Enterobacter sakazakii during processing and storage of plain yogurt were investigated. Preheated rehydrated milk was inoculated with a cocktail culture of E. sakazakii (103 cfu/mL of milk) and/or with thermophilic yogurt starter culture of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus. The inoculated milk was incubated at 40C for 5 h, then the samples were cooled and subsequently stored at 4C for up to 7 days. The results showed that E. sakazakii grew at an early stage of fermentation but declined at the end of the process. There was no significant difference between the populations of E. sakazakii in the presence or absence of lactic acid bacteria during the first 4 h of the incubation period but there was significant difference during the last hour of the incubation period. The populations of E. sakazakii decreased significantly during cooling and storage of yogurt (pH 4.2,4.7) compared with nonfermented milk samples at 4C. The presence of E. sakazakii did not have a significant effect on the growth of LAB during fermentation and storage of yogurt. The results obtained from this study indicate that the pH of yogurt and storage temperature were critical to the survival and growth of E. sakazakii in the manufacture of plain yogurt. PRACTICAL APPLICATIONS Enterobacter sakazakii prevalence in milk products and the production environment has been documented. The results obtained from this study may be of use to dairy producers to manufacture safe products using thermophilic lactic acid bacteria. These bacteria decreased the pH of milk in less than 5 h, resulting in E. sakazakii reduction. pH of yogurt during the fermentation process is a critical control point that should be monitored to produce safe products. [source]

REDUCTION OF PATULIN IN APPLE JUICE CONCENTRATES DURING STORAGE

JOURNAL OF FOOD SAFETY, Issue 1 2005
NURAY KOCA
ABSTRACT In this study, the reduction of patulin content in apple juice concentrates during 6 months of storage at 22 and 30C was investigated. Results demonstrated that reduction in patulin content was dependent on the storage temperature and time. Patulin reductions after 1 month of storage at 22 and 30C were in the ranges of 45,64% and 66,86%, respectively. Levels of patulin were below detectable limits after 4 months of storage at 22 and 30C. [source]

POTENTIAL FOR BACTERIAL GROWTH ON THE FRESH CUT TROPICAL SQUASH, CALABAZA (CURCUBITA MOSCHATA), DURING STORAGE

JOURNAL OF FOOD SAFETY, Issue 3 2003
REBECCA MONTVILLE
ABSTRACT Calabaza (Curcubita moschata) is a tropical squash which is gaining popularity as a specialty crop for agricultural producers in the Northeast United States. It is commonly marketed by being cut in half, wrapped in plastic and may be held unrefrigerated until sold. This method of display is essential for consumer acceptance, yet unrefrigerated storage means that some potential for food safety problems exists. Experiments were conducted to determine the potential for bacterial growth during storage of cut calabaza. Freshly cut calabaza contained between 1.3 and 4.7 log10CFU/g aerobic mesophiles. By 10 h, duplicate counts from some samples exceeded 4 log10 CFU/g. After 24 h of room temperature storage, total aerobic plate counts ranged from 5.2 to 7.7 log10 CFU/g. Rapid bacterial growth on cut calabaza stored at room temperature indicates that these products are highly perishable, and may be able to support the growth of pathogenic bacteria, should they be introduced during the slicing process. [source]

SURVIVAL OF THREE SALMONELLA SEROTYPES ON BEEF TRIMMINGS DURING SIMULATED COMMERCIAL FREEZING AND FROZEN STORAGE

JOURNAL OF FOOD SAFETY, Issue 2 2001
G.A DYKES
ABSTRACT This study investigated the survival of three Salmonella serotypes (S. Brandenberg, S. Dublin and S. Typhimurium) on beef trimmings during simulated commercial freezing, frozen storage for 9 months and subsequent abusive slow thawing and refreezing conditions. This was achieved by plating samples monthly and after thawing and refreezing on nonselective Tryptic Soy Agar (TSA) and selective Xylose Lysine Desoxycholate Agar (XLD) and incubating both at 37C for 24 h to determine Salmonella counts, aerobic counts and the presence, if any, of sublethal injury of this pathogen. Two freezing temperatures (,18C or ,35C) to simulate slow or rapid freezing respectively, and two inoculation levels (103 cfu g,1 or 105 cfu g,1) were used. Aerobic counts and counts of all the Salmonella serotypes did not change significantly (p > 0.05) during frozen storage or for any of the other treatments applied in this study. This finding was attributed to the insulating nature of the subcutaneous fat layer in this manufacturing cut. These results are important with respect to food safety associated with ground beef processing. [source]