Retardation by Glandless Cottonseed Flour of Lipid Oxidation and Discoloration in Raw Ground Beef Containing Salt

Salt (NaCl) was added to raw ground beef at levels of 0, 0.5, 1, 2 or 3% of the weight of the meat and defatted glandless cottonseed flour (GCF) was added at 0 or 3% levels. Patties were made with these mixes and stored for 3 or 6 days at 4°C or for 30 or 60 days at –20°C. Lipid oxidation (TBA values) in samples stored at 4° and –20°C and discoloration in samples stored at 4°C were determined. In samples made with salt only, TBA values within each storage period for each storage temperature increased with increasing salt levels up to 2%; increasing salt from 2 to 3% decreased TBA values. GCF markedly reduced TBA values at each salt level. Discoloration of samples stored at 4°C was also decreased by GCF.     

Storage Stability of Intermediate Moisture Mullet Roe

A storage stability study was performed on intermediate moisture roe (a_w= 0.84, salt content = 4%). Samples were stored at various temperatures for up to 1 month. Microbial analyses indicated that bacteria could grow from 5–25°C. Fungi grew at 15° and 25°C while their growth was inhibited at 5°C; however, a lag phase was detected at 15°C. TBA values increased linearly during storage. Microbial analyses, chemical determination of rancidity and sensory evaluations showed that the product was still acceptable after 30 days storage at 5°, 15° or 25°C.     

Effect of Further Processing and Storage of Mechanically Deboned Chicken on Proximate Composition, Thiamin, Riboflavin and TBA Values

Mechanically deboned chicken (MDC), and its further processed products, frankfurters (FK) and bolognas (BG), were evaluated for proximate composition, thiamin, riboflavin and TBA values following processing and storage. Vitamin concentrations were found stable in MDC stored at 2°C for 2 days or at – 18°C for 180 days. The processing of FK and BG reduced the vitamin levels by0–12% on a dry weight basis. Storage of FK and BG for 42 days at 2°C or 180 days at – 18°C had no measurable effect on vitamin content. TBA values were generally low except their increases were significant in the salted MDC held at – 18°C. Proximate composition varied among products but was not affected by storage time and temperature.     

The effect of pH,sodium chloride,sodium nitrite and storage temperature on the growth of Clostridium perfringens and faecal streptococci in laboratory media

The effects of salt concentration (1–12% w/v) in combination with unheated sodium nitrite (0–400 μg/ml) on growth of mixed strains of Clostridium perfringens and of faecal streptococci at three pH values (5.6, 6.2, 6.8) and storage temperatures ranging from 10°C to 35°C is reported. At pH 6.2, following storage at 15°C, 1% salt and 50 μg/ml nitrite inhibited growth of C. perfringens. At 20°C and pH 6.2, 200 μg/ml nitrite plus 3% salt, or 50 μg/ml plus 4% salt were required to inhibit growth. Growth of C. perfringens was prevented by levels of curing salts used commercially providing the pH was 6.2 or below. At pH 6.8 or above at least 4% salt and 50 μg/ml nitrite was required to prevent growth at 20°C. The faecal streptococci grew in medium containing 6% salt and 400 μg/ml nitrite irrespective of pH or storage temperature. In 8% salt growth was prevented by storing at or below 17.5°C or, if pH was 6.2 or lower, by adding 200 μg/ml nitrite irrespective of storage temperature. Growth of faecal streptococci was not controlled by concentrations of curing salts which would be acceptable in meat products.     

Physicochemical Changes Occurring During Storage of Precured Beef Blends at Different Temperatures and Two Levels of Salt

Preblends of lean beef (20% water, 75 ppm nitrite, 3 or 6% salt) were stored at -10, 0 and 15°C and samples were analyzed at 0, 1, 2 and 3 days of storage. Emulsifying capacity (per 100 mg of total protein) was not significantly different between the 3 and 6% salt levels; and, was not significantly affected by storage temperature but decreased with storage time. The viscosities of the extracts were not significantly affected by the amount of added salt or the temperature of storage; however, they increased significantly during storage. Water-holding capacity increased significantly with the quantity of salt and length of storage time. Correlation analysis resulted in a negative correlation between pH and viscosity and a positive correlation between pH and salt soluble proteins. Surprising was the significant negative correlation between emulsifying capacity and water-holding capacity.     

Lipid Oxidation in Ground Beef Patties as Affected by Time-Temperature and Product Packaging Parameters

Oxidative rancidity in fresh and stored ground beef samples was measured using a thiobarbituric acid (TBA) assay with antioxidant protection. The independent variables were fat concentration (15 or 30%), package type (polyethylene or vacuum-packaged), freezer storage temperature (-12.2°, -23.3° or -34.4°C) and storage time (4, 8, 12, 16, or 20 weeks). At the end of each storage time samples were thawed and TBA values were determined on the samples before and after cooking. TBA values increased during the first 12 to 16 weeks after which time it decreased for both the cooked and uncooked samples. The higher fat samples, packaged in polyethylene, had higher TBA values for both cooked and uncooked patties. Uncooked patties stored at - 12.2°C had higher TBA values than those stored at -23.3°C or -34.4°C but cooked sample TBA values showed no dependence on storage temperature.     

Packaging Film Permeability in Conjunction with Sodium Nitrite, Potassium Sorbate or Lactic Acid Starter Culture for Control of Clostridium sporogenes (PA3679) Growth in Sliced Bologna

A sliced bologna was prepared and inoculated with Clostridium sporogenes (PA3679), packaged in films ranging in oxygen permeability from 0.1 cc/m²/24 hr to 120 cc/m²/24 hr and stored at 5°C, 15°C or 25°C. Subsequent bologna preparations included either 156 ppm sodium nitrite, 0.26% potassium sorbate or a lactic acid starter culture. Water activity, pH, TBA number and PA3679 counts were monitored during 28 days of storage. TBA numbers increased in packages with over 60 cc/m²/24 hr permeability but PA3679 counts did not change as a function of packaging film. Nitrite and sorbate were equally effective as inhibitors. At 15°C and 25°C, the lactic acid culture allowed the least PA3679 growth. Oxygen permeability did not alter any inhibitory effects even when increased TBA numbers resulted from using an oxygen-permeable film.     

Sodium Lactate Effects on Shelf-Life, Sensory, and Physical Characteristics of Fresh Pork Sausage

The objective of our study was to evaluate the effects of various levels (0%, 1%, 2%, 3%) of sodium lactate on selected physical, sensory, and microbiological characteristics of fresh pork sausage stored at 4°C for 28 days. Samples containing 0% and 1% SL reached 10⁸ CFU/g after 10 days refrigerated storage. Addition of 2% or 3% SL to fresh pork sausage delayed microbial deterioration, pH decline, and development of sour- and off-flavors 7 days at 4°C. Samples containing 2% SL did not reach total plate counts of 10⁸ CFU/g until 24 days storage. SL appeared to protect red color, and to “enhance” pork-and salty-flavors in sausage. TBA, L-, a-, and b-values were unaffected by SL level.     

Combination effect of sodium lactate and irradiation on color,lactic acid bacteria,lipid oxidation and residual nitrite in Chinese sausages during storage at 25 °C

Chinese sausages, with the addition of 0 or 2% sodium lactate, were vacuum‐packaged and stored overnight at 4°C. Refrigerated sausages were gamma‐irradiated at 0, 3 or 5 kGy absorbed dose. Meat samples were stored at 25°C for up to 30 days. Color, lactic acid bacteria, pH, lipid oxidation and residual nitrite were determined during storage. Irradiated samples were reduced in redness as a result of irradiation and storage time. Irradiation at 5 kGy alone or in combination with 2% sodium lactate and irradiation at 3 kGy could completely inhibit lactic acid bacterial growth. Thiobarbituric acid reactive substances (TBARS) values decreased as the pH values of samples increased. Sodium lactate decreased TBARS values of all samples and protected against a decrease of residual nitrite during storage. Irradiation reduced residual nitrite in Chinese sausage, and residual nitrite decreased with increased time. Copyright © 2004 Society of Chemical Industry     

Lipid Oxidation and Sensory Analysis of Cooked Pork and Turkey Stored under Modified Atmospheres

Precooked pork and turkey were stored at 4°C for 18 hr and at - 20°C for 3 months in vacuum and in atmospheres of air, carbon dioxide, and nitrogen. For both short-term refrigerated storage and long-term frozen storage, vacuum-packaging of precooked turkey and pork resulted in more meaty and less warmed-over flavor and aroma than the other packaging treatments. Samples stored in carbon dioxide and nitrogen atmospheres were less “oxidized” as indicated by sensory scores and TBA values than those stored in air but were more “oxidized” than vacuum-packaged meat. Warmed-over and rancid flavor and aroma scores correlated highly and consistently with TBA values, but inconsistently with the less sensitive fluorescence method. Vacuum-packaged turkey was darker and redder than other samples after frozen storage.     

EXTENDING THE CHILLED SHELF LIFE OF VACUUM-PACKAGED GROUND BEEF USING ASCORBIC ACID, NITRITE OR SALT

The objective of this study was to extend the shelf life of ground beef in chilled conditions. Samples were treated with 2% salt, 2% salt  +  500-ppm ascorbic acid, or 2% salt  +  100-ppm sodium nitrite. The control sample did not contain any additives. Protein, nitrite, moisture contents, pH, thiobarbituric acid (TBA) value, color attributes and microbial counts of samples were determined. Samples were vacuum packaged and stored in refrigeration, and chemical and microbial analyses were performed throughout storage. The pH of samples decreased during storage, and the sample having 2% salt and 500-ppm ascorbic acid had the greatest pH decline. TBA values generally increased ( P <  0.05) with storage time. Samples having 2% salt  +  500-ppm ascorbic acid had the lowest TBA value. On a given storage day, samples having 2% salt  +  100-ppm sodium nitrite had lower microbial microbial count than other samples, indicating the antibacterial effect of nitrite. A significant storage time  ×  treatment interaction ( P <  0.05) existed for almost all quality parameters studied.

PRACTICAL APPLICATIONS

Ground beef has commercial importance for the meat industry in Turkey. Meat processors have difficulties in marketing ground beef because of its relatively low shelf life. By adding ascorbic acid or salt, it is possible to extend shelf life and preserve its color, and to limit lipid oxidation, which will collectively help to increase market share of ground beef.     

Chilled storage life of hot-boned, pre-rigor, salted minced beef

Pre-rigor beef mince with 2% added salt was stored under CO₂ at −1.5 °C (A). The same mince with 100 ppm sodium nitrite was stored under CO₂ at 5 °C (B) and −1.5 °C (C), and under vacuum at −1.5 °C (D). Microbiological and sensory analyses were carried out for up to 21 weeks. Indicative storage life was taken as the time for microbial numbers to reach 10⁷ colony forming units per g. Mince stored under regimes B or D attained these numbers by 6 and 14 weeks, respectively; mince stored under regimes A and C had not attained these numbers by the end of the storage trial. Mince stored at 5 °C developed storage flavours of sufficient intensity to be detectable by consumers by 9 weeks storage. In general, the other minces did not develop unacceptable levels of storage or off flavours. Over 90% of the added sodium nitrite had disappeared after 10 weeks of storage, partly through conversion to sodium nitrate. Mince pH was not affected by the storage conditions and remained at about 6.0. The water holding capacity of the pre-rigor mince deteriorated during prolonged storage.     

Precooking Method Affects Warmed-over Flavor of Broiler Breast Patties

Broiler breast patties cooked in a water bath (85°C vs 95°C) or oven (160°C vs 180°C) to an internal temperature of 83°C were stored at 3°C foT 3 days, reheated, and evaluated by headspace GC and thio-barbituric acid (TBA) methods. Cooking temperature within the same cooking medium had no effect on TBA values or headspace GC profiles of cooked, stored samples. During post-cooking storage TBA values and several headspace volatiles increased. The changes were more severe in oven-cooked than water-cooked patties, which could have been partly due to lower moisture content of the oven-cooked patties. Significant correlations were found between TBA values and several major headspace volatiles (pentanal, hexanal, heptanal, and total volatiles).     

DRYING AND STORAGE TREATMENTS FOR OVERCOMING DORMANCY IN MALTING BARLEY

A batch of deeply dormant Triumph barley was stored at ?18°C. The grain was so dormant that its viability, 97–98%, could not be determined using standard tests. Samples were dried to 12% moisture at various rates by varying the temperature and relative humidity of the drying air. Dried samples were stored at three temperatures (15°, 27° and 38°C). At intervals the germination characteristics of subsamples were determined. Germinability improved with storage time, improving faster at the higher temperatures. However some of the samples stored at 27°C and all the samples stored at 38°C suddenly showed a loss of viability, preceded by a loss in vigour. The rate of recovery from dormancy was independent of the drying regime used. Initially the germinability of the barley was 5–10% (1 ml agar test) and 0–4% (3 ml agar test). Recovery from dormancy was extremely slow at 15°C, so that after a year germination values were around 80% (1 ml agar test) and 45% (3 ml agar test). After 27 weeks the viability of grain stored at 27°C began to decline, germinability was 85–90% (1 ml agar test) and 50–60% (3 ml agar test). At 38°C the initial decline in dormancy was rapid, but germinability fell catastrophically at various times between 3 and 30 weeks storage. Other samples of the same lot of Triumph barley were dried to various moisture contents, 9.4%, 10.3%, 11.0%, 13.0% and 14.5%. These were stored at 38°C. The initial rate of recovery from dormancy was rapid, and was unrelated to the moisture content of the grain. The samples dried to 9.4% and 10.3% m.c. achieved germination values close to the viability value, around 95% (1 ml agar test) and 90% 3 ml (agar) tests in 15–18 weeks storage and showed no signs of deterioration in 30 weeks. Grain held at 11% moisture deteriorated after 12 weeks and that stored at 13% and 14.5% deteriorated after 3 weeks. The germinabilities of the samples dried to 9.4% and 10.3% and stored for 15–18 weeks at 38°C were so good, reaching maximal values at 2 days in the germination test, that it is concluded that they could probably not be matched by samples stored cool. The possibility of using higher storage temperature to overcome dormancy and water sensitivity more rapidly, is discussed. Experiments with other grain samples have confirmed that, in most respects, the original barley was typical of deeply dormant Triumph. Samples of Carmargue and Golden Promise matured much more rapidly than Triumph. However water sensitivity was extremely persistent in a sample of Doublet.     

Evaluation of Milk Mineral Antioxidant Activity in Beef Meatballs and Nitrite-cured Sausage

ABSTRACT: The objective of this study was to determine the antioxidant activity of 1.5% milk mineral (MM) added to uncured cooked beef meatballs and to evaluate possible synergistic effects of MM in combination with 20-ppm or 40-ppm sodium nitrite in beef sausages. All treatments were also formulated with 1.5% salt and 10% added water. Thiobarbituric acid (TBA) values and Hunter color values were determined at 1 d, 8 d, and 15 d of storage at 2°C. Meatball cooked yield was also measured. Cooked yield was not different (P < 0.05) between control meatballs and those containing MM. As expected, treatments containing nitrite had higher redness ( CIE a* ) than samples without nitrite. Redness values increased with storage time in sausages containing 40-ppm nitrite. However, redness values decreased (P < 0.05) during storage for control meatballs, associated with increased lipid oxidation (higher TBA values). Lipid oxidation was lower ( P < 0.05) in samples containing 1.5% MM with TBA values <1.2 after 15 d of storage compared with 6.1 for control samples. There was no synergistic inhibition of lipid oxidation in samples containing 20-ppm or 40-ppm sodium nitrite plus 1.5% MM. Milk mineral alone at 1.5% of meat weight was sufficient for inhibition of lipid oxidation in cooked beef samples.     

Changes in Quality of All-Beef and Soy-Extended Patties as Influenced by Freezing Rate, Frozen Storage Temperature, and Storage Time

All-beef and soy-extended patties were frozen to - 18°C in either 24, 48, 72 or 96 hr and stored at -23, -18 or -7°C for 0, 6, 9, 12, 18 or 24 months prior to evaluating various quality factors. In evaluations made immediately post-freezing, freezing to - 18°C in 96 hr reduced beef flavor intensity and juiciness for both types of patties. Except for juiciness, storage at -7°C for just 6 months produced sizeable reductions in quality. Longer storage produced gradual, but continual deteriorations in quality, especially color, odor, flavor and TBA values. Inclusion of soy reduced many of the negative effects of storage on quality.     

The influence of storage temperature and storage time on color stability,retail properties and case-life of retail-ready beef

Steaks from three different muscles were either vacuum or carbon dioxide packed and stored for up to 24 weeks at three different storage temperatures (−1.5, 2, or 5 °C). Following storage, they were displayed for up to 30 h. CIE color coordinates, the oxidative states of myoglobin and pH were measured and muscle color, surface discoloration, retail appearance, and odor were evaluated prior to storage and during display (0, 1, 2, 4, 6, 24 and 30 h), and/or immediately prior to and following display. Prior to display, pH was negatively related to duration of storage, and samples stored at −1.5 °C had the highest and samples stored at 5 °C, had the lowest pH. Perception of muscle color was influenced by duration of storage and display, but lower storage temperatures appeared to produce a stabilizing effect. Both lightness of muscle color and deoxymyoglobin content were apparently not influenced by storage temperature or duration of storage or display. Both oxymyoglobin (OMB) and redness, as defined by CIE a* values, were lost progressively during storage and display, but this loss was progressively lower as storage temperature decreased. Yellowness of muscle color, as defined by CIE b* values, generally decreased as storage was prolonged, and this decrease was observed more quickly at higher storage temperatures. Surprisingly, b* values were not related to duration of display. Both surface discoloration and metmyoglobin (MMB) content increased progressively during storage and display. Samples stored at 5 °C displayed the most surface discoloration, while samples stored at −1.5 °C contained the least MMB and displayed the least surface discoloration. Retail appearance deteriorated progressively during storage in all samples stored at 2 and 5 °C and in samples stored at −1.5 °C, which were displayed for at least 24 h. Retail appearance also deteriorated progressively during display in samples stored at −1.5 and 2 °C for three weeks or longer and in samples stored at 5 °C for 0 to 15 and 24 weeks. In unstored samples, samples to be stored at −1.5 °C generally received the lowest retail appearance scores, but after prolonged storage and display, samples stored at −1.5 °C received higher retail appearance scores than samples stored at 5 °C, particularly when samples were stored for 12 weeks or longer and displayed for 1 h or more. Odor deteriorated progressively during storage when measured both prior to display and after 30 h of display. In samples stored for three weeks or longer, samples stored at −1.5 °C generally received the lowest odor scores and were perceived to have the least prevalent off-odors. Samples stored at −1.5 °C maintained a retail case-life of 30 h, when stored for up to 17 weeks, while samples stored at 2 and 5 °C maintained a retail case-life of 30 h, when stored for only eight and seven weeks, respectively. Consequently, storage life can be more than doubled by storage at subzero temperatures (−1.5 °C).     

Antioxidant effect of turmeric powder,nitrite and ascorbic acid on stored chicken mince

This investigation was carried out to evaluate the antioxidant effect of turmeric (turmeric 1000 ppm, turmeric 5000 ppm), nitrite (nitrite 200 ppm) and ascorbic acid (ascorbic acid 500 ppm) on raw minced chicken stored at 4 ± 1 °C. Physicochemical properties [pH, water activity, cooking loss, thiobarbituric acid (TBA) value, peroxide value (PV), free fatty acid (FFA)] were evaluated on 0, 2, 4 and 6th day of storage. Highly significant differences (P < 0.01) in pH, TBA value, PV and FFA value were noticed between treatments and between storage periods. TBA values were observed to be lowest for nitrite 200 ppm and then turmeric 5000 ppm, and there was no significant difference between nitrite 200 ppm and turmeric 5000 ppm, and both were superior to ascorbic acid 500 ppm and turmeric 1000 ppm. Among different treatments, PV was found to be lowest in turmeric 5000 ppm and highest in nitrite 200 ppm. FFA value was found to be lowest in turmeric 5000 ppm and highest in ascorbic acid 500 ppm among all treated samples. It can be concluded that turmeric has potential to replace synthetic antioxidants presently used in meat processing with many added advantages.     

Freezing Qualities of Raw Ovine Milk for Further Processing

Raw whole ovine (sheep) milk was frozen at −15°C and −27°C and microbiological and physico-chemical properties were evaluated periodically. Total bacteria decreased at a faster rate in milk stored at −15 than at −27°C. Acid degree values for milk stored at −15°C were significantly higher than that stored at _27°C. Samples stored at −15°C exhibited protein destabilization after 6 mo of storage, while those stored at −27°C were stable throughout the 12-mo storage period.Frozen ovine milk was evaluated in several products including cheese, yogurt, and whey protein concentrates. Products produced from milk frozen at −27°C exhibited good sensory and functional characteristics. Ovine whey showed a higher proportion of β-lactoglobulin, about the same proportion of α-lactalbumin and lower proportions of serum albumin and immunoglobulin than bovine whey. Ovine whey protein concentrate showed significantly better foam overrun, foam stability, and gel strength than bovine or caprine whey protein concentrates.     

Sensory and Chemical Characteristics of Pork Chops as Affected by Precooking, Curing and Frozen Storage

Four processing procedures were compared as methods of reducing warmed-over flavor (WOF) of pork chops during frozen storage for 84 days, These procedures were (1) oven-broiled chops, (2) chops from loins precooked with no additives, (3) chops from loins cured with 0.5% salt and 40 ppm NaNO2 and precooked, and (4) chops from loins cured with 2% salt and 120 ppm NaNO2 and precooked. Samples were evaluated by the TBA test, Warner-Bratzler shear, hydroxyproline assay and by sensory analysis after frozen storage at -18°C. Chops from the three precooked treatments were more tender than oven-broiled chops. Nitrite inhibited WOF development of precooked chops during frozen storage and 40 ppm nitrite was nearly as effective as 120 ppm.