Quality Loss (quality + loss)

Distribution by Scientific Domains


Selected Abstracts


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]


Lipid damage during frozen storage of Gadiform species captured in different seasons

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 6 2007
Santiago P. Aubourg
Abstract Quality loss of two gadiform fish species (blue whiting, Micromesistius poutassou; hake, Merluccius merluccius) during frozen storage (,30 and ,10,C; up to 12,months) was studied. For this, hydrolytic (formation of free fatty acids, FFA) and oxidative (conjugated dienes, peroxide and interaction compound formation) lipid damage were analysed. For both species, individual fishes captured in two different trials (May and November) were considered. Increasing (p,<0.05) lipid hydrolysis and oxidation (peroxide and interaction compound formation) were observed for all kinds of samples throughout the frozen storage. Interaction compound detection by fluorescence analysis showed the best correlation values with storage time. Some higher (p,<0.05) hydrolysis development could be observed in hake captured in May than in its counterpart from the November trial, while frozen blue whiting did not provide definite differences for FFA formation between both trials. Concerning peroxide formation, higher (p,<0.05) values were obtained for individual blue whiting and hake captured in November when compared to their corresponding May fish for both frozen storage conditions. Interaction compound formation was also found to be higher (p,<0.05) for November hake fish than for its counterpart captured in May, while blue whiting did not provide definite differences between trials. [source]


The use of packaging techniques to maintain freshness in fresh-cut fruits and vegetables: a review

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2009
M Alejandra Rojas-Gra
Summary Browning and other discolourations, softening, surface dehydration, water loss, translucency, off-flavour and off-odour development, as well as microbial spoilage are some of the most frequent causes of quality loss in fresh-cut products. Nowadays, the use of innovative modified atmospheres and edible coatings stands out among other techniques in the struggle for maintaining freshness and safety of fresh-cut fruits and vegetables. A few studies have demonstrated the effectiveness of these techniques when applied to different fresh-cut commodities. However, treatment and storage conditions for fresh-cut fruits are still being largely explored to better keep their fresh-like quality attributes. This review discusses the recent advances in the use of innovative modified atmosphere packaging (MAP) systems to maintain freshness of fresh-cut fruits and vegetables. Furthermore, special attention is devoted to the development of coatings that can be used as a complement or alternative to MAP. [source]


Hot air dehydration of figs (Ficus carica L.): drying kinetics and quality loss

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2004
Antonio Piga
Summary The dehydration of fruit from fig trees is normally achieved by sun drying. There is concern about the safety of the end product, mainly because there is a risk of the development of aflatoxins. These concerns can be overcome by artificial drying (oven dehydration). Fig fruits of a local cultivar, which were either pre-treated by blanching or blanching plus sulphuring or not treated at all, underwent hot air dehydration under mild processing conditions in a pilot airflow cabinet dryer. Sampling was carried out at regular intervals to calculate the rate of dehydration and assess quality changes. Microbiological counts and nonenzymatic browning were also monitored. Pretreatments resulted in a shorter processing time, compared with control fruits. In general, a falling dehydration rate period was observed. A dramatic loss of ascorbic acid was recorded, while an informal sensorial assay of the dried fruits gave a positive assessment. [source]


Three-dimensional MRI mapping of minimum temperatures achieved in microwave and conventional food processing

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2001
John R. Bows
Microbiological assurance protocols for food preservation are based on the ,worst-case' slowest heating point within the food product. For conduction-limited processing, this leads to well-known overheating near surface regions of products, with resultant quality loss. For volumetric heating processes such as microwave heating, it is practically impossible to guarantee where the slowest heating point will be. Consequently, microwave heating regimes are generally excessive and product quality is often similar to conventional conduction-limited heating processes. It is well known that Magnetic Resonance Imaging (MRI) can provide three-dimensional (3D) images which quantify the spatial distribution of water in foods, and also that the MRI parameters of water are temperature dependent. The present study demonstrates that a combination of these two concepts has led to a new approach for the validation of thermal processing in food manufacture. The potential for on-line assurance of minimum and maximum temperatures for manufacture of microbiologically assured, minimally processed, high quality food is discussed. [source]


INFLUENCE OF FROZEN PERIOD ON THE PROXIMATE COMPOSITION AND MICROBIOLOGICAL QUALITY OF NILE TILAPIA FISH (OREOCHROMIS NILOTICUS)

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2010
SHIMELIS A. EMIRE
ABSTRACT The rationale of the study was to investigate the influence of frozen period on quality of fish fillet. The proximate composition and microbiological analyses were carried out at 15 days interval on tilapia fish fillets during frozen storage. It was found that the protein, moisture and ash contents decreased significantly (P < 0.05) during the entire storage period. However, the fat content increased from 0.37 0.01 to 0.56 0.01 g/100 g of fillet. The total volatile bases nitrogen and pH values also increased significantly The total bacterial load in fresh fillets was reduced from 2.57 106 to 8.2 105 cfu/g after 90 days of frozen storage. The total coliforms decreased from 460 to 23 MPN/g and the fecal coliforms decreased from 23 MPN/g to undetectable level, respectively. Thus, a significant quality loss was observed for tilapia during storage. However, the present frozen conditions retained the fish material under acceptable microbiological conditions for human consumption. PRACTICAL APPLICATIONS The main challenge that fish industries face in developing countries like Ethiopia is to comply with consumer expectations, particularly on product quality. The quality of fresh fish is one of the key factors that govern the shelf life of the final product at low temperature preservation. The Ethiopian fish production and marketing enterprise is vested with the responsibility of inland fisheries processing and marketing. The enterprise, without any scientific basis, labeled the frozen tilapia fish shelf life to be 9 months. Therefore, the aim of this study was to investigate the low-temperature (,18C) preservation technique practiced by the enterprise in order to evaluate the influence of frozen period on quality of a fish fillet. The results on changes in proximate composition and microbial load of Nile tilapia fish fillet enabled to determine the frozen period of a fish fillet that can be fit for human consumption devoid of deterioration. The results can also be used for further investigation and detailed research is required to help commercial processors beyond 90 days of frozen storage. [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]


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]


Microbiological and Sensorial Quality Assessment of Ready-to-Cook Seafood Products Packaged under Modified Atmosphere

JOURNAL OF FOOD SCIENCE, Issue 9 2009
B. Speranza
ABSTRACT:, The effects of modified atmosphere packaging (MAP) (30:40:30 O2:CO2:N2 and 5:95 O2:CO2) on the quality of 4 ready-to-cook seafood products were studied. In particular, the investigation was carried out on hake fillets, yellow gurnard fillets, chub mackerel fillets, and entire eviscerated cuttlefish. Quality assessment was based on microbiological and sensorial indices determination. Both packaging gas mixtures contributed to a considerable slowing down of the microbial and sensorial quality loss of the investigated seafood products. Results showed that sensorial quality was the subindex that limited their shelf life. In fact, based primarily on microbiological results, samples under MAP remained acceptable up to the end of storage (that is, 14 d), regardless of fish specie. On the other hand, results from sensory analyses showed that chub mackerel fillets in MAP were acceptable up to the 6th storage d, whilst hake fillets, yellow gurnard fillets, and entire cuttlefish became unacceptable after 10 to 11 d. However, compared to control samples, an increase in the sensorial shelf life of MAP samples (ranging from about 95% to 250%) was always recorded. Practical Application: Modified atmosphere packaging (MAP) is an inexpensive and uncomplicated method of extending shelf life of packed seafood. It could gain great attention from the fish industrial sector due to the fact that MAP is a practical and economic technique, realizable by small technical expedients. Moreover, there is great attention from the food industry and retailers to react to the growing demand for convenience food, thus promoting an increase in the assortments of ready-to-cook seafood products. [source]


Control of internal browning and quality improvement of ,Fuji' apples by stepwise increase of CO2 level during controlled atmosphere storage

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2005
Hun-Sik Chung
Abstract To control internal browning injury and to reduce quality loss in ,Fuji' apples during storage, a stepwise controlled atmosphere (CA) method was applied in this study. Both non-bagged and bagged apples during maturation were stored at 0 C under 1% O2 + 1% CO2, 1% O2 + 3% CO2 or air for 10 months, and 1% O2 + 1% CO2 for 2 months followed by 1% O2 + 3% CO2 for 8 months (stepwise CA). The concentrations of internal ethylene and carbon dioxide in apples kept for 24 h at 20 C after storage under CA conditions were maintained at low level, but there was no effect of stepwise CO2 increase on internal gas concentrations. The non-bagged and bagged apples stored under stepwise CA were not significantly different from those stored under 1% O2 + 3% CO2 continuously for 10 months in term of flesh firmness, titratable acidity and yellowing index. However, the apples stored under stepwise CA were firmer, more acid and greener than those stored under 1% O2 + 1% CO2 continuously for 10 months. Internal browning injury occurred in apples stored under 1% O2 + 3% CO2 continuously for 10 months, but it was suppressed completely by stepwise CA storage. The stepwise CA, increasing of CO2 level after holding at 1% CO2 for the first 2 months of storage, was effective in maintaining the quality and controlling the internal browning injury in non-bagged and bagged ,Fuji' apples. Copyright 2005 Society of Chemical Industry [source]


The relative impact of meteorological observations in the Norwegian regional model as determined using an energy norm-based approach

ATMOSPHERIC SCIENCE LETTERS, Issue 1 2010
Andrea Storto
Abstract The sensitivity of the forecasts to different observation groups is evaluated by comparing moist total energy norm-based cost functions within the HARMONIE/Norway regional model. We quantify the quality loss associated to each observation type. The use of a localisation operator has allowed us to obtain results for the whole domain and for the area of continental Norway only, as well as for different vertical sub-regions of the atmosphere. Results show a prominent role of in situ observations for short-range forecasts, while for medium-range forecasts microwave satellite observations result in the largest impact, especially the AMSU-A channels peaking within the troposphere. Copyright 2010 Royal Meteorological Society [source]


Control of Pathogenic and Spoilage Microorganisms in Fresh-cut Fruits and Fruit Juices by Traditional and Alternative Natural Antimicrobials

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2009
Rosa M. Raybaudi-Massilia
ABSTRACT:, Traditional antimicrobials have been extensively used for many years. However, consumers are currently demanding wholesome, fresh-like, and safe foods without addition of chemically synthesized preservatives. The application of novel natural antimicrobials to assure safety of fresh-cut fruits and unpasteurized juices while preventing quality loss is a promising alternative. The effectiveness of these natural substances added to fruit derivatives has been studied by different researchers. Antimicrobials of animal (lactoperoxidase, lysozyme, and chitosan), plant (essential oils, aldehydes, esters, herbs, and spices), and microbial origin (nisin) can be used to effectively reduce pathogenic and spoilage microorganisms in fresh-cut fruits and fruit juices. Nevertheless, the use of these compounds at a commercial level is still limited due to several factors such as impact on sensory attributes or, in some cases, regulatory issues concerning their use. Therefore, extensive research on the effects of each antimicrobial on food sensory characteristics is still needed so that antimicrobial substances of natural origin can be regarded as feasible alternatives to synthetic ones. [source]


Quality preservation in chilled and frozen fish products by employment of slurry ice and natural antioxidants

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2009
Isabel Medina
Summary Fish products are known to provide high levels of constituents important for the human diet. At the same time, wild and farmed fish species are highly perishable products, the quality and freshness of which rapidly declines post-mortem. Accordingly, efficient storage and processing technologies need to be employed to reduce postmortem quality losses until the product reaches the consumer. The present review covers recent efforts carried out on some new and advanced strategies related to chilled and frozen storage. In the first part, research concerning the use of binary systems (slurry ice) is reviewed, this focussed on the commercialisation of fresh fish products as such or to its employment as raw material for processing. Then, the application of exogenous antioxidants to ensure retention of high quality is addressed; in this part, special attention is accorded to the endogenous antioxidant content retention and to the antioxidant/pro-oxidant balance in fish foods. [source]


NONLINEAR CONSTRAINED OPTIMIZATION of THERMAL PROCESSING II.

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2003
FINITE CYLINDRICAL GEOMETRIES, VARIABLE PROCESS TEMPERATURE PROFILES to REDUCE PROCESS TIME, to IMPROVE NUTRIENT RETENTION IN SPHERICAL
ABSTRACT Conventional methods for thermal processing of foods use constant processing temperature profiles (CPTPs) for a prescribed processing time, which is based on achieving a required microbial lethality to comply with public health standards. This also results in degradation of nutrients and quality factors. the variable process temperature profiles (VPTPs) obtained by using optimization methods can reduce quality losses and/or processing time compared to CPTPs. the objective of this research was to evaluate VPTPs using the Complex Method to reduce the processing time and/or improve quality retention for a specified level of lethality in thermal processing of conduction heated foods. the VPTPs were obtained for volume average retention of thiamine considering different sizes of spheres (small and large) and finite cylinders (small and large), and the thiamine retention and processing time results were compared with a conventional method (processing at 121.1C) for a specified lethality level. the use of VPTPs resulted in a 37 and 10% decrease in processing times in spherical and 40 % and 6 % for finite cylindrical shapes, for the same objective function value and specified lethality compared to the CPTP process. For the same processing time, the improvements in thiamine destruction were 3.7 and 2 % for spheres, and 3.9 and 2.2% for finite cylinders. [source]


SELECTED DRYING CONDITIONS AND STORAGE PERIOD AND QUALITY OF WALNUT SELECTIONS

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2003
M. A. KOYUNCU
Walnut selections were hulled at harvest time, and 3 and 5 days after harvest to determine the effects of hulling time on postharvest quality. Walnuts removed from their hulls were stored shelled and unshelled under ambient conditions after being dried at selected conditions. Among the tested hulling dates, the best results were obtained from the walnuts hulled at harvest time. At the end of the storage period, the least quality losses were determined in the walnuts dried in the sun. Generally, quality losses in the shelled walnuts were greater than quality losses in the unshelled walnuts. According to the research results, walnuts removed from their hulls and dried under sun can be stored under ambient conditions (21 1C and 50,65 RH) and retain acceptable quality for 12 months. [source]


Preservation of Microstructure in Peach and Mango during High-pressure-shift Freezing

JOURNAL OF FOOD SCIENCE, Issue 3 2000
L. Otero
ABSTRACT: A histological technique was used to evaluate modifications on the microstructure of peach and mango due to classical methods of freezing and those produced by high-pressure-shift freezing (HPSF). With the high-pressure-shift method, samples are cooled under pressure (200 MPa) to -20C without ice formation, then pressure is released to atmospheric pressure (0.1 MPa). The high level of supercooling (approximately 20C) leads to uniform and rapid ice nucleation throughout the volume of the specimen. This method maintained the original tissue structure to a great extent. Since problems associated with thermal gradients are minimized, high-pressure-shift freezing prevented quality losses due to freeze-cracking or large ice crystal presence. [source]


Use of alginate or zein as edible coatings to delay postharvest ripening process and to maintain tomato (Solanum lycopersicon Mill) quality

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008
Pedro Javier Zapata
Abstract BACKGROUND: Edible coatings could be effective tools for delaying the ripening process of fruits. Alginate or zein as edible coatings were assayed in tomato in order to maintain parameters related to quality during postharvest storage. RESULTS: Coated tomatoes showed lower respiration rate and ethylene production than control ones, with a twofold lower concentration of ethylene precursor. In addition, the evolution of parameters related to tomato quality losses, such as softening, colour evolution and weight loss, was significantly delayed (4,6 days on average) in coated tomatoes as compared to controls. Thereafter, sugars, organic acids (and especially ascorbic acid) and scores from sensory analysis remained at much higher levels at the end of storage in treated than in control tomatoes. CONCLUSIONS: Coatings based on alginate or zein could be effective tools for delaying the tomato-ripening process during postharvest storage, and in turn maintaining tomato quality and its acceptability by consumers. Copyright 2008 Society of Chemical Industry [source]


Infrared Heating in Food Processing: An Overview

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2008
Kathiravan Krishnamurthy
ABSTRACT:, Infrared (IR) heating provides significant advantages over conventional heating, including reduced heating time, uniform heating, reduced quality losses, absence of solute migration in food material, versatile, simple, and compact equipment, and significant energy saving. Infrared heating can be applied to various food processing operations, namely, drying, baking, roasting, blanching, pasteurization, and sterilization. Combinations of IR heating with microwave heating and other common conductive and convective modes of heating have been gaining momentum because of increased energy throughput. This article reviews aspects of IR heating and presents a theoretical basis for IR heat processing of food materials and the interaction of IR radiation with food components. The effect of IR on food quality attributes is discussed in the context of samples and process parameters. Applications of IR heating in food processing operations and future research potential are also reviewed. [source]