Frozen Storage Time Research Articles

EFFECTS OF ADJUNCTS ON RESTRUCTURED PORK

ABSTRACTBoneless pork shoulders were excised 24h postmortem, frozen, tempered, flaked and blended with one of the four formulations: (1) 1% NaCl and .25% sodium tripolyphosphate (STP); (2) .5% NaCl, .5% KCl and .25% STP; (3) 1% NaCl, .25% STP and .125% lecithin; or (4) .5% NaCl, .5% KCl, .25% STP and .125% lecithin. The blended samples were converted to restructured chops and stored at ‐ 18C until evaluated at 5, 14 and 56 days. Appearance and taste attributes were measured objectively and subjectively. Objective and subjective measurements of color and other visual traits revealed that storage time affected these traits more than the adjuncts; whereas, all treatments had a minimal effect on texture and juiciness. Increased frozen storage time and lecithin contributed to flavor degradation and increased TBA values. Further research is needed to determine the effect of varying amounts of lecithin on oxidative rancidity of restructured muscle foods.

Studies on thermal treatment of hake. Part 2. Effects of thermal treatment and frozen storage on volatile ammonium bases content.

Dynamics of volatile ammonium bases (VAB) in minced meat of the Pacific hake (Merluccius productus) in function of heating temperature (40, 60, 80, 100, 120 and 130 degrees C) and of storage duration (3-8 months at -28 degrees C) was followed. A gradual increase in the VAB content was found with increasing temperature and frozen storage time; the increase proved statistically significant when compared to the VAB content in the control.

Studies on thermal treatment of hake Part 1. Effects of thermal treatment and frozen storage on the content of SH groups and rheologic properties of hake flesh

AbstractEffects of frozen storage (3–8 months at –28° C) and heating temperatures (40, 60, 80, 100, 120 and 130° C) on SH groups content and minced meat hardness of the Pacific hake (Merluccius productus) were studied. Of the two factors under study, temperature effects proved dominating, both on the SH dynamics and on hardness. The duration of frozen storage did not influence the maximum content of SH groups: it affected only the location of the peak of the thiol groups contents temperature curve. Additionally, a high correlation between the SH content and hardness was found as a function of heating temperature; the correlation, however, became weaker with frozen storage time.

Vacuum-Packaged Trimmings as a Source for Ground Beef Patties: Changes During One Year of Frozen Storage

Vacuum-packaged beef trimmings were stored for four time periods of 0, 1, 2 and 3 wk (4 lots) at 5°C. After the storage period, the four lots of trimmings were evaluated for chemical, microbial and sensory properties. Each lot was then made into beef patties. Two lots of patties (0 and t wk of storage at 5°C) were further stored at −18°C for 0, 3, 6, 9 and 12 months and used to determine sensory properties. The two lots prepared from trimmings stored for 2 and 3 wk were evaluated for chemical properties at 0, 6, 9 and 12 months of −18°C frozen storage. Patties prepared from vacuum-packaged beef trimmings stored for 2 and 3 wk had significantly lower sensory ratings as compared to ratings for patties made from trimmings stored for 0 or 1 wk. Microbial counts indicated that bacterial action could be more important than oxidative rancidity as the cause for these changes. Increased length of frozen storage time did not markedly affect sensory properties.

Structural Stability of Fresh and Frozen‐Thawed‘Valencia’(C. sinensis) Orange Juice

ABSTRACTValencia orange juice was subjected to different freezing rates and different storage times to study the effects of those treatments on the structural and dispersion properties of the insoluble particles. Examination with an electron microscope revealed that the juice contained plastids, mitochondria, oil droplets and cell walls. Fragments consisting mainly of vesicular membranes were present both before and after freezing and thawing. A slow freezing rate resulted in plastids with various degrees of disintegration. Separation of insoluble particles from the juice serum increased with increasing frozen storage time and was especially apparent at slower primary freezing rates. A decrease in color intensity and deterioration in appearance is related to longer storage time and to slower primary freezing rates.

Chemical and Sensory Assessment of Nonspawning Capelin (Mallotus villosus) Subjected to Long Term Frozen Storage

ABSTRACTNonspawning capelin (Mallotus villosus) were processed immediately after being caught, after 5 days of iced storage or after being frozen at sea and later thawed. Fish from all variables were stored at −23°C for up to 21 months. Both pre‐processing treatment and frozen storage time significantly (P ≤ 0.05) affected all sensory variables except appearance. Regardless of treatment, the sensory quality was very stable during early and intermediate stages of frozen storage; capelin processed at sea was superior to that of the other two treatments. Appearance, dimethylamine, timethylamine, moisture and thiobarbituric acid values were dependent upon an interaction between pre‐processing treatment and frozen storage time. Hypoxanthine concentration had the greatest potential as an index of sensory quality.

Chemical and Sensory Assessment of Roundnose Grenadier (Macrourus rupestris) Subjected to Long Term Frozen Storage

ABSTRACTRoundnose grenadier (Macrourus rupestris) were filleted either immediately when they were caught or after storage (gutted or ungutted) in ice for different periods of time. The fillets were frozen and then stored at −23°C for up to 24 months. Both pre‐freezing treatment and frozen storage time significantly (P < 0.05) affected all sensory variables. The sensory quality was very stable during early and intermediate stages of frozen storage and compared very favorably to that reported for other groundfish species. Dimethylamine, trimethylamine, and moisture concentrations were also significantly affected by both pre‐freezing treatment and frozen storage time but extractable protein nitrogen and hypoxanthine were dependent upon an interaction between both major treatments. The usefulness of any of the chemical variables as indices of sensory quality was questionable.

Organoleptic assessment of products frozen by two methods: liquid nitrogen and blast freezing

SummaryMacaroni cheese, poached fish, carrots and coq au vin were prepared and frozen by two methods, liquid nitrogen and blast freezing. The precooked frozen food was stored in the frozen state at – 18°C either for less than 18 days or more than 6 weeks. The products were reheated and rated by a taste panel for appearance, texture, odour and flavour; they were also assessed for degree of like or dislike.Products frozen by both methods were not significantly different except in respect of the texture and flavour of macaroni cheese which had been stored in the frozen state for more than 6 weeks. In these instances the liquid nitrogen product was rated higher than the blast frozen product. These results indicate therefore that for the products tested, liquid nitrogen freezing of multiportion packs of cooked products offers no appreciable advantage over freezing food in an efficient blast freezer, particularly when the frozen storage time is short.

FREEZING OF RAW BEEF: INFLUENCE OF AGING, FREEZING RATE AND COOKING METHOD ON QUALITY AND YIELD

The combined effects of aging, freezing rate, frozen storage and cooking method on beef quality and yield were studied in a multifactorial experiment, using 1.5 cm slices of LD muscles from young steers. Aging for 2 wk resulted in significantly more tender, but slightly less juicy frozen meat than aging for 4 days. Prolonged frozen storage gave tougher meat and a larger tenderness difference between aging times. Freezing rates of 13, 2.0 and 0.04 cm/h differed but little in their effect on sensory quality, but slightly lower yield and redness value were noted for the lowest rate. Pan frying directly from the frozen state resulted in slightly higher juiciness and cooking yield, with larger differences in yield between freezing rates, than cooking after previous thawing. Significant interactions were noted for cooking method × freezing rate and for aging time × frozen storage time

Measurements of the dielectric properties of frozen and defrosted meat and fish in the frequency range 10–200 MHz

AbstractDielectric constant and loss tangent were determined for lean meat (beef) and for codfish over the temperature range −25° to +10° and frequency range 10–200 MHz. More limited determinations were made for pork, animal fats and herring. The measurements were made using a Boonton RX‐meter for which a suitable test cell and measuring technique had been developed.The measuring technique is described and the results obtained presented in curves and tables showing the effects on dielectric properties of temperature, frequency, frozen storage time and the variability of dielectric properties of the raw material.The objective of the work done has been to obtain the raw material constants necessary for studying and evaluating the process of dielectric defrosting of meat and fish. The results are discussed from this standpoint.