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Frozen Storage (freeze + storage)
Selected AbstractsChanges in the Radical-Scavenging Activity of Bitter Gourd (Momordica charantia L.) during Freezing and Frozen Storage with or without BlanchingJOURNAL OF FOOD SCIENCE, Issue 7 2008C. Myojin ABSTRACT:, The effects of blanching, freezing, and frozen storage on the retention of radical-scavenging activity (RSA), total phenolics, and ascorbic acid in bitter gourd were investigated. Blanching of sliced bitter gourd resulted in considerable losses of RSA and total phenolics, and most extensively, of ascorbic acid. In the subsequent frozen storage at ,18 °C, RSA and total phenolic content of unblanched and blanched bitter gourd underwent little change for 90 d then gradually declined, but at ,40 °C, they practically remained unchanged throughout the entire storage period. On the contrary, ascorbic acid content of both unblanched and blanched bitter gourd decreased abruptly at the early stage in frozen storage. The results show that blanching of bitter gourd improves the retention of RSA and total phenolics during subsequent frozen storage but markedly aggravated loss of ascorbic acid. Finally, it is to be noted that RSA, total phenolics, and ascorbic acid originally contained in the raw bitter gourd were overall best retained by quick freezing followed by frozen storage at ,40 °C without preceding blanching. [source] Evaluation of Lipid Oxidation and Oxidative Products as Affected by Pork Meat Cut, Packaging Method, and Storage Time during Frozen Storage (,10 °C)JOURNAL OF FOOD SCIENCE, Issue 2 2007S.Y. Park ABSTRACT:, Lipid oxidation and oxidative volatiles as affected by pork meat cut and packaging method during frozen storage at ,10 °C were evaluated. Pork belly cut had higher thiobarbituric acid reactive substance (TBARS) and pH values than did the loin, whereas the loin had higher free fatty acid (FFA) values than that of the belly cut. Peroxide values increased with increased storage time, but were not affected by pork meat cut and packaging method. Volatiles with carbon numbers less than 10 in the belly cut were higher than those in the loin cut, whereas those with carbon numbers greater than 10 in the loin cut were higher than those in belly cut. Most volatiles were decreased with increased storage time, except for propane. Both 4-pentenal and 4-methyl-2-hexanone in the belly cut showed a positive correlation with FFA, whereas 2,4-dimethyl-1-heptene and 9-octadecenal in the loin cut were positively correlated with TBARS and FFA, respectively, even though the values were not high enough to predict the degree of lipid oxidation. [source] Functional and Thermal Gelation Properties of Squid Mantle Proteins Affected by Chilled and Frozen StorageJOURNAL OF FOOD SCIENCE, Issue 6 2003M.C. Gómez-Guillén ABSTRACT: Fresh squid (Loligo vulgaris) mantles that underwent chilled and frozen storage were studied for their ability to form thermal gels as well as the effects of changes to the functional and chemical properties of the muscle proteins during storage. Assays of protein extractability in 5% NaCl, apparent viscosity, autolytic activity, and SDS-PAGE (of the soluble fraction) were carried out periodically. After 4 d of chilled storage, there was a significant drop in protein functionality that negatively affected the thermal gelation profile. The rate of proteolysis remained very high throughout frozen storage, however functional properties and thermal behavior remained very stable. [source] Effects of different pre-freezing blanching procedures on the physicochemical properties of Brassica rapa leaves (Turnip Greens, Grelos)INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2006Alicia del Carmen Mondragón-Portocarrero Summary For optimal freeze storage, green vegetables should first be blanched. The present study compared four different procedures for the blanching of grelos (leaves of Brassica rapa L.): steaming for 2 min, immersion in boiling water for 2 min, immersion in boiling water containing 1% citric acid for 1 min, and immersion in boiling water containing 5% citric acid for 1 min. After blanching, the grelos were stored for up to 120 days at ,18 °C, with sampling at two-weekly intervals for analysis of physicochemical properties (ash weight, vitamin C content, pH, acid value, moisture content and CIEL*a*b* colour variables). In almost all respects steam blanching gave the best results: notably, vitamin C losses were markedly lower, while moisture content and colour remained closer to those of the fresh product. [source] | ||||||||||