Storage Stability Of Products Research Articles

Fatty acid oxidation of pistachio nuts stored under various atmospheric conditions and different temperatures

The fatty acid composition and stability of whole-split pistachio nuts were investigated at ambient conditions and under air and 98% CO2 at monolayer moisture content and different storage temperatures. High stability was determined under CO2 storage particularly at 10°C. It was revealed that, from the Arrhenius model, storage under CO2 was more temperature sensitive. A 18·24–72·05 reduction for linolenic and 2·15–20·16% for linoleic acid were observed depending on storage conditions. Rate constants of fatty acid oxidation at three temperatures and ambient conditions and Ea for various storage systems were estimated. Peroxide value and free fatty acid of pistachio nuts were also determined as indicators of product storage stability. Least product oxidation and hydrolysis occurred at or near the monolayer moisture content and under CO2 storage.© 1998 SCI.

Assessment of the Hygienic Characteristics of a Beef Carcass Dressing Process

Swab samples were obtained from the surfaces of randomly selected beef carcasses passing through a high-speed dressing process. A single sample was obtained from each selected carcass from one of 10 sites. At each of 3 points in the process, 25 samples were obtained from each carcass site. The aerobic bacteria, coliforms, and Escherichia coli recovered from each sample were enumerated. Values for the means and standard deviations of each set of 25 values were calculated on the assumption that each set of values was log-normally distributed. The E. coli data indicated relatively heavy (mean log numbers > 2/100 cm2) contamination of carcasses with E. coli during the skinning of posterior sites; redistribution of E. coli, from relatively heavily to relatively lightly (mean log numbers about 0/100 cm2) contaminated sites during evisceration operations, and reduction of E. coli numbers at most sites as a result of trimming and washing operations. However, posterior sites remained the most heavily contaminated with E. coli. The findings for coliforms were similar to those for E. coli. In contrast, the total count data indicated heavy (mean log numbers > 3/cm2) contamination of anterior (brisket) sites as well as posterior sites and little redistribution of bacteria during evisceration operations. After trimming and washing operations, the mean log total numbers at most sites were about 2/cm2, but one brisket site remained heavily contaminated. It is suggested that E. coli or coliform data are appropriate for assessing carcass dressing processes for hazard analysis critical control point (HACCP) system purposes, while total count data are inappropriate for that purpose but may be appropriate, in relation to product storage stability, for quality management (QM) system purposes.

Synthesis of novel organic oligomers containing SiH bonds

AbstractSeveral organic oligomers (Mw = 103–104 order) containing SiH bonds of the general formula 1 have been successfully synthesized by platinum‐catalyzed partial hydrosilylation reaction of an allyloxy (or an allyl carbonate) end‐blocked linear organic oligomer 2 with 2,4,6,8‐tetramethylcyclotetrasiloxane, [CH3(H)SiO]4 (3) (hereafter called hydrocyclotetrasiloxane). 1H‐NMR spectroscopy confirmed the introduction of hydrocyclotetrasiloxane moiety into the oligomers through SiC linkage by hydrosilylation reaction. 13C‐NMR analysis revealed that the cyclic structure of the starting hydrocyclotetrasiloxane 3 was retained intact in product 1. As the precursor for 1, allyloxy (or allyl carbonate) end‐blocked oligomers 2 could be prepared from hydroxyl‐terminated oligomers 4. The storage stability of product 1 was significantly influenced by the platinum catalyst still remaining in it. The poor stability was improved by decreasing the amount of the platinum catalyst and/or by adding coordinating compounds. As a result, an excellent stability of product 1 was obtained. © 1993 John Wiley & Sons, Inc.

Stability of Freshwater Sucker (Catostomus spp.) Flesh During Frozen Storage

Freshwater suckers (Catostomus spp.) were harvested from Lakes Huron, Michigan, and Superior during different seasons of the year. Initial compositional analyses and storage stability of products held at −18 °C for periods of 1, 3, 6, and 12 mo were determined for coarsely ground (eviscerated) fish, minced flesh, and loin and belly flap muscles. Moisture levels ranged from 75.3 to 83.5%, showing no consistent differences among lakes, harvest dates, or fish portions. Calcium levels of minced flesh averaged 0.08%, only about one tenth of that from coarsely ground fish. Lipid analyses (2-thiobarbituric acid test, TBA) showed increased lipid oxidation with storage time. Those results indicate that untreated minced flesh may be stored frozen for at least 6 mo without serious lipid oxidation, since TBA numbers averaged < 2.0 at that storage time. Lipids in loin muscle were least oxidized, followed by minced flesh, belly flap, and coarsely ground fish, respectively. Key words: fish, mechanically deboned, storage stability, sucker, lipid oxidation