The Effect of Sodium Hexametaphosphate on Cottage Cheese Yields

A major concern in the cottage cheese industry is the inefficient use of the available milk proteins. Currently, the methods of cottage cheese manufacture convert an average of only 74.9% of the milk proteins into cottage cheese, while the remainder are removed in the by-product whey (43, 56). As protein is the main determinant of both the yield and nutritional value of cottage cheese, if 25% of the available protein is lost to the whey, then potential cottage cheese yield and nutrition have been lost as well. The proteins lost in the whey are mainly -lactalbumin and β-lactoglobulin, which remain soluble during the conditions of cottage cheese manufacture and thus do not become part of the curd (38, 39). Although these proteins have the highest known nutritional value (21, 22, 45, 60, 71), they can be an added expense rather than a benefit to the dairy industry. The proteins as whey solids must either be processed further, disposed of, or both. Processing whey is expensive and difficult because cottage cheese whey is both dilute, 94% water, and highly acid, pH 4.6, (3, 9, 39, 65). Concurrently, the products produced by processing cottage cheese whey such as animal feeds, dried or concentrated products, and fermentation products have a limited and competitive market and are not highly profitable (39, 51). However, disposal is a less attractive and more expensive alternative because whey has a high biochemical oxygen demand (BOD) making it 3 major pollutant requiring high levels of microbial action for treatment (3, 10). Public response to whey as a pollutant has forced the passing of statutes forbidding the disposal of untreated whey into lakes, streams, and rivers. Concurrently, whey disposal in sewage systems has become increasingly expensive (3, 9, 39). The whey protein, as part of the whey, thus present a temperamental enigma and overshadowing dilema to the cottage cheese industry: being the most nutritious proteins known, they remain virtually too unprofitable to process, but too expensive to throw away. Recovery of some of the proteins dissolved in the whey is possible by the use of polyelectrolytes that will precipitate the whey proteins, allowing them to be recovered by centrifugation (25, 28, 33, 34). The substances reported to provide the largest recovery are carboxymethyl cellulose (CMC) and several phosphate compounds such as sodium hexametaphosphate (SHMP). If the procedures for recovering proteins from the whey using polyelectrolytes could be combined with the procedures for manufacturing cottage cheese, then the finished product would include the whey proteins, providing higher yields and nutritional value. The objective of this study was to explore the possibility that polyelectrolytes may increase the yield of cottage cheese by removing proteins from the whey and adding them to the curd. The chosen additives were screened, and then the yields and composition of cottage cheese made by a widely accepted culture procedure (70) were compared with the yield and composition of cottage cheese made from milk containing 0.05 or 0.2 sodium hexamctaphosphatc

Acrylamide in potato crisps prepared from 20 UK-grown varieties: effects of variety and tuber storage time

Twenty varieties of field-grown potato were stored for 2 months and 6 months at 8 °C. Mean acrylamide contents in crisps prepared from all varieties at both storage times ranged from 131 μg per kg in Verdi to 5360 μg per kg in Pentland Dell. In contrast to previous studies, the longer storage period did not affect acrylamide formation significantly for most varieties, the exceptions being Innovator, where acrylamide formation increased, and Saturna, where it decreased. Four of the five varieties designated as suitable for crisping produced crisps with acrylamide levels below the European Commission indicative value of 1000 μg per kg (Saturna, Lady Rosetta, Lady Claire, and Verdi); the exception was Hermes. Two varieties more often used for French fries, Markies and Fontane, also produced crisps with less than 1000 μg per kg acrylamide. Correlations between acrylamide, its precursors and crisp colour are described, and the implications of the results for production of potato crisps are discussed

Existing antivirals are effective against influenza viruses with genes from the 1918 pandemic virus

The 1918 influenza pandemic caused more than 20 million deaths worldwide. Thus, the potential impact of a re-emergent 1918 or 1918-like influenza virus, whether through natural means or as a result of bioterrorism, is of significant concern. The genetic determinants of the virulence of the 1918 virus have not been defined yet, nor have specific clinical prophylaxis and/or treatment interventions that would be effective against a re-emergent 1918 or 1918-like virus been identified. Based on the reported nucleotide sequences, we have reconstructed the hemagglutinin (HA), neuraminidase (NA), and matrix (M) genes of the 1918 virus. Under biosafety level 3 (agricultural) conditions, we have generated recombinant influenza viruses bearing the 1918 HA, NA, or M segments. Strikingly, recombinant viruses possessing both the 1918 HA and 1918 NA were virulent in mice. In contrast, a control virus with the HA and NA from a more recent human isolate was unable to kill mice at any dose tested. The recombinant viruses were also tested for their sensitivity to U.S. Food and Drug Administration-approved antiinfluenza virus drugs in vitro and in vivo. Recombinant viruses possessing the 1918 NA or both the 1918 HA and 1918 NA were inhibited effectively in both tissue culture and mice by the NA inhibitors, zanamivir and oseltamivir. A recombinant virus possessing the 1918 M segment was inhibited effectively both in tissue culture and in vivo by the M2 ion-channel inhibitors amantadine and rimantadine. These data suggest that current antiviral strategies would be effective in curbing the dangers of a re-emergent 1918 or 1918-like virus