Increasing Storage Time (increasing + storage_time)

Distribution by Scientific Domains

Selected Abstracts

Comparison of quality and shelf life of buffalo meat patties stored at refrigeration temperature

Gurunathan Kandeepan
Summary Scientific investigation on the quality changes of processed meat products will boost and sustain the meat production and utilization in buffalo abundant countries. A programme was undertaken to compare the quality of buffalo meat patties made from intensively reared young male, semi extensively reared spent male and female groups and stored at refrigeration temperature (4 ± 1 °C). Buffalo meat patties were evaluated for shelf life attributes by analysing the changes in physicochemical, microbiological and sensory attributes. The overall acceptability of patties was better in spent buffalo group than young male group. Increasing storage time resulted in significantly higher pH, TBARS, total aerobic mesophils, coliforms, Staphylococcus aureus and psychrophilic counts but decreased appearance, flavour, juiciness, tenderness, connective tissue residue and overall acceptability scores of buffalo meat patties. The patties were well acceptable within 20 days in young male group and 25 days in spent buffalo group respectively during refrigerator storage. [source]


ABSTRACT The objective of this study was to predict the sensory properties of stored roasted peanuts using instrumental methods. Roasted peanuts were stored at 20 treatment combinations of temperature (23, 30, 35 and 40C) and water activity (Aw; 0.33, 0.44, 0.54, 0.67 and 0.75 Aw), then evaluated after storing for up to 91 days using descriptive analysis (n = 12) and instrumental methods. Stored samples were also evaluated by consumers (n = 50). Regression models (adj. R2 , 0.70) indicated that increasing storage Aw resulted in decreasing color lightness (L value). Increasing storage time and Aw increased both measured Aw and percent moisture of roasted peanuts. Sensory texture attribute intensities were best predicted by percent moisture (adj. R2 , 0.78), whereas consumer ratings were best predicted (adj. R2 , 0.74) by color or percent moisture. Instrumental texture analyses did not predict descriptive or consumer ratings. While percent moisture was the best predictor of consumer acceptance of stored roasted peanuts, color was an excellent alternative predictor and employed a much simpler assay. [source]

Gel Strengthening Effect of Wood Extract on Surimi Produced from Mackerel Stored in Ice

A.K. Balange
ABSTRACT:, The effect of ethanolic kiam wood extract (EKWE) and commercial tannin (CT) on the gel properties of surimi produced from mackerel (Rastrelliger kanagurta) stored in ice for different times (0 to 12 d) was studied. During 12 d of iced storage, pH, total volatile base (TVB), trimethylamine (TMA), and trichloroacetic acid (TCA)-soluble peptide contents as well as thiobarbituric acid-reactive substances (TBARS) of mackerel mince increased while myosin heavy chain (MHC) band intensity decreased continuously (P,< 0.05). The result suggested that deterioration, protein degradation, and lipid oxidation proceeded with increasing storage time. For corresponding surimi, TVB and TMA were almost removed and TBARS and TCA soluble peptide contents were decreased. Conversely, MHC became more concentrated. Decreases in gel-forming ability of surimi were observed when fish used as raw material were stored in ice for a longer time, regardless of EKWE or CT addition. Whiteness of surimi gel decreased and expressible moisture increased especially when the storage time increased. However, superior breaking force and deformation of surimi gel with 0.15% EKWE or 0.30% CT added, compared to those of the control gel were observed during the first 6 d of the storage. Thereafter, EKWE and CT had no gel enhancing effect on surimi. Therefore, freshness was a crucial factor determining gel enhancing ability of EKWE or CT toward mackerel surimi. [source]

Antioxidative Ability, Dioscorin Stability, and the Quality of Yam Chips from Various Yam Species as Affected by Processing Method

Y.-M. Liu
ABSTRACT:, The antioxidative ability, stability of storage protein dioscorin, and the quality of fried yam chips from different cultivars of Chinese yams influenced by various processing treatments were investigated. Total phenolic content and DPPH free radical scavenging effect were found to be the highest in Mingchien (MC) and the lowest in Keelung (KL) yam. Following processing, freeze-dried yams of all varieties showed the least decrease in total phenolic compounds and DPPH radical scavenging effect, while boiling caused the greatest decrease in both. Fresh yams of all varieties contained the highest dioscorin contents comparing with their counterparts. Boiling and deep-frying caused severe protein denaturation resulting in loss of dioscorin solubility after purification. Freeze-drying resulted in increase in protein surface hydrophobicity (So); nonetheless, it attained higher total phenol content, antioxidative capacity, and dioscorin stability of yams compared with other processing treatments. The peroxide values of all yam chips increased during the initial stage, then declined with advanced storage. Fracturability of all yam chips gradually decreased, due to the absorption of moisture, with increasing storage time. [source]

Volatile Compounds of Raw Beef from 5 Local Spanish Cattle Breeds Stored Under Modified Atmosphere

K. Insausti
ABSTRACT Volatile compounds of raw beef from Asturiana de los Valles, Morucha, Parda Alpina, Pirenaica, and Retinta cattle breeds were studied. Steaks were packaged under 60% O2, 30% CO2, and 10% N2, and 53 volatile compounds were tentatively identified by purge-and-trap extraction and gas chromatography with mass spectrometry after 0, 5, 10, and 15 d of chill storage. The degradation of beef quality with increasing storage time was evidenced by the increase in 2,3,3-trimethylpentane, 2,2,5-trimethylhexane, 3-octene, 3-methyl-2-heptene, 2-octene, and 2-propanone and by the decrease in dimethyl sulfide. Consequently, some of the volatile compounds, which are believed to be formed by thermal degradation of meat, might be formed during chill storage, and the rate of formation of some was dependent on the specific compound. [source]

Properties of refrigerated ground beef treated with potassium lactate and sodium diacetate

Miros, aw Fik
Abstract BACKGROUND: Ground meat is product that perishes easily and therefore various preservatives are applied to prolong its shelf life. The aim of this study was to investigate the effect of potassium lactate and sodium diacetate (Protec K-DI preparation) on general proteolytic activity, protein degradation, texture, colour and water-holding capacity of vacuum-packaged ground beef. RESULTS: The activity of endogenous proteolytic enzymes, and hence the rate of protein hydrolysis changed significantly (P < 0.05) during refrigerated storage. The proteolysis was more intensive in the meat with the preservative than in a control sample. According to the results of SDS-PAGE, the level of myosin in ground beef decreased with increasing storage time, whereas the preservative did not have a significant effect (P > 0.05) on these changes. However, its impact was the most significant in the case of tropomyosin and troponin T content, as well as changes of 30 kDa protein content. The preservative as well as the increase in storage time influenced an increase in content of polypeptides, peptides and some amino acids in the samples, and had an inhibiting effect on unfavourable changes in ground beef hardness. The preservative addition allowed the meat to maintain desired meat colour, and the main pigment during refrigerated storage was oxymyoglobin (MbO2). CONCLUSION: Results showed that the Protec K-DI preparation can be useful in minced meat production as a good stabiliser of colour and texture despite the increase observed in proteolytic activity after the preservative addition. Copyright © 2007 Society of Chemical Industry [source]

In vitro starch digestibility of fresh and sun-dried faba beans (Vicia faba L.)

Luis A Bello-Pérez
Abstract Fresh and sun-dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 °C and analysed for available starch (AS), resistant starch (RS) and fibre-associated resistant starch (FARS) contents as well as ,-amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The ,-amylolysis rate decreased with increasing storage time, i.e. long-stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. Copyright © 2007 Society of Chemical Industry [source]

Gene expression measurements in the context of epidemiological studies

ALLERGY, Issue 12 2008
C. Bieli
Background:, Gene expression measurements became an attractive tool to assess biological responses in epidemiological studies. However, collection of blood samples poses various technical problems. We used gene expression data from two epidemiological studies to evaluate differences between sampling methods, comparability of two methods for measuring RNA levels and stability of RNA samples over time. Methods:, For the PARSIFAL study, PBLC of 1155 children were collected using EDTA tubes in two countries. In the PASTURE study, tubes containing RNA-stabilizing solutions (PAXgene® Blood RNA Tubes; PreAnalytiX) were used to collect cord blood leucocytes of 982 children in five countries. Real-time PCR (conventional single tube assay and high-throughput low density arrays) was used to quantify expression of various innate immunity genes. In 77 PARSIFAL samples, gene expression was measured repeatedly during prolonged storage. Results:, In PARSIFAL (EDTA tubes) the median RNA yield after extraction significantly differed between the two centres (70 and 34 ng/,l). Collecting blood into an RNA-stabilizing solution markedly reduced differences in RNA yield in PASTURE (range of medians 91,107 ng/,l). The agreement [Spearman rank correlation (r)] between repeated measurements of gene expression decreased with increasing storage time [e.g., for CD14: r (first/second measurement) = 0.35; r (first/third measurement) = 0.03]. RNA levels measured with either the conventional method or low-density arrays were comparable (r > 0.9). Conclusion:, Collecting blood samples into tubes containing an RNA-stabilizing solution increases RNA yield and reduces its variability. Long-term storage of samples may lead to RNA degradation, requiring special attention in longitudinal studies. [source]

Packaging materials for fermented milk: effects of material crystallinity and polarity on food quality

S. E. A. Jansson
Abstract The ability of a packaging material to protect the food product and extend its shelf-life depends on several material properties. In this work the effects of material crystallinity and polarity on the quality of fermented milk were studied. The fermented milk is a high-quality Swedish product, similar to yoghurt. The quality of the food product was determined as a function of storage time by containing the liquid in pouches of different materials. The material crystallinity was varied by using very low-density polyethylene, high-density polyethylene and aluminium laminate as packaging materials. Aluminium was used on account of its ,100%' gas-tightness. The polarity was varied by comparing an aliphatic polyketone with polyethylene of similar crystallinity. The carbon dioxide (CO2) and oxygen (O2) contents in the headspace of the pouches were determined. The food quality was determined by measuring whey syneresis, viscosity and the content of desired Bifidobacteria, as well as of undesired yeast and mould. A trained taste panel determined the degree of acidity and of the sparkling taste. It was found that the content of CO2 increased and that of O2 decreased in the pouches with increasing degree of crystallinity and increasing polarity. The sparkling taste of fermented milk was a clear function of the headspace CO2 content. The data presented here could thus be used to ,design' a package for a desired sparkling taste of the fermented milk by selecting a certain material crystallinity. Whey syneresis, viscosity and content of Bifidobacteria were found to be independent of pouch material. While the degree of whey syneresis and the viscosity increased with increasing storage time, the content of Bifidobacteria slowly decreased. The content of yeast and mould in the liquid was below the existing limit values for foodstuffs. The degrees of acidity and sparkling taste were highest for the liquids contained in aluminium and polyketone pouches, although the differences in acidulous taste between the various pouch materials were small. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Persistence and efficacy of two diatomaceous earth formulations and a mixture of diatomaceous earth with natural pyrethrum against Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) on wheat and maize

Basileios J Vayias
Abstract Laboratory tests were conducted to assess the insecticidal and residual effects of three diatomaceous earth (DE) formulations, Insecto®, PyriSec® and SilicoSec®, against Tribolium confusum Jacquelin du Val on wheat and maize. Quantities of wheat and maize were treated with the above formulations at 500, 1000 and 1500 mg kg,1 and stored at 25 °C and 55% relative humidity (RH). Samples were taken on the day of storage and every 30 days until completion of a 360 day period of storage. Adults of T. confusum were exposed to these samples at 25 °C and 55% RH and the mortality was measured after 24 and 48 h and 7 and 14 days of exposure. Adult mortality was higher on wheat than on maize. At the beginning of the storage period, mortalities after 14 day exposure on maize treated with the highest rate were 60, 63 and 81% for Insecto®, PyriSec® and SilicoSec® respectively, while on wheat the mortality was 100% for all DEs. On the same commodities 360 days after treatment the respective mortality figures for wheat were 99, 98 and 100%, while in the case of maize they did not exceed 7%. Generally, mortality at exposures ,48 h decreased with increasing storage time. Furthermore, although mortality on wheat increased with dose, the increase in DE dose from 1000 to 1500 mg kg,1 resulted in only a small increase in mortality. Thus a DE treatment of 1000 mg kg,1 was shown to provide long-term protection of wheat against T. confusum, although higher DE application rates and exposure intervals are needed for a satisfactory level of protection of maize against this pest. Copyright © 2006 Society of Chemical Industry [source]