Canadian Institute of Food Technology Journal最新文献

Forty-one samples of dry commercial gravy bases (involving ten brands), and 44 prepared gravies from these bases were collected from 28 restaurants, drive-ins and coffee houses in the Edmonton area. All samples were examined for SPC, and for presence of coliforms, thermophiles, coagulase-positive staphylococci, salmonellae and Cl. perfringens. No salmonellae or Cl. perfringens were detected in any of the samples examined. Some gravy bases and gravies showed presence of coliforms, thermophiles, coagulase-positive staphylococci and other bacteria. All coliforms and staphylococci were eliminated after three-minute boiling, but SPC and thermophile counts decreased very slowly during further boiling. A number of ingredients used in the preparation of gravy bases also were investigated. Some coagulase-positive staphylococci were detected in onion powder and ground savory, and large numbers of coliforms were detected in ground sage, marjoram, alaman paprika and black pepper. However these organisms were eliminated after three-minute boiling. The investigations revealed that there was little danger for foodborne illnesses from gravies prepared from commercial gravy bases, providing one follows the preparation instructions, boil the gravies for at least five minutes, and hold the product at 160°F prior to serving.

Comparison of the color and processing qualities of berries stored in nitrogen with those of berries stored in air (both at 3.3°C for up to 12 weeks) showed that in a nitrogen atmosphere berries could be stored longer with less decay yielded a better sauce and juice than when stored in air.

Sauce from cranberries stored for six weeks in nitrogen atmospheres was superior in flavor to sauce from berries stored in air and equivalent in flavor to sauce from freshly harvested berries. Color measurements indicated significant enhancement of the color of whole nitrogen stored berries. With nonenzymic juice extraction, nitrogen stored berries yielded darker juice than air stored berries but with enzymic extraction the differences were not apparent. Storage in nitrogen significantly increased the titratable acidity of the juice.

Fat accumulation occurred in the myocardium of young rats fed docosenoic acid provided by liquid or partially hydrogen-ated rapeseed oil or partially hydrogenated herring oil. The composition of the cardiac fatty acids and the histopathology in rats receiving oil as 40% of calories were studied after 3, 7, 14 and 28 days. In those fed liquid rapeseed oil, a peak accumulation was reached at 7 days and thereafter decreased, and the concentration of docosenoic acid was higher than in those fed the hydrogenated oils.

A zero-effect level of abnormal fat deposition from liquid rapeseed oil was found to be 5% by weight of the diet or 10% of calories. Further increases in the level of dietary rapeseed oil enhanced the cardiac fat droplets and the accumulation of dietary fatty acids, particularly docosenoic acid.

Canbra oil had no effect on lipid accumulation in the heart.

A new process is described by which a comparatively high yield of leaf protein concentrate may be obtained from alfalfa, white clover or pea vines. The leaves were first comminuted and the juice pressed from the pulp; the nitrogenous compounds were then precipitated with a measured volume of polar solvent (acetone or ethanol) added to the juice and finally the precipitate was washed with the solvent. A tasteless, odorless and creamy colored fine powder was obtained after air drying. The effect of some of the process variables on the yield of concentrate were examined, Losses of water from the leaves in the field decreased the yield of concentrate sharply. Allowing leaf juice to stand at room temperatures favored enzymatic proteolysis. Recovery of protein concentrate increased as the proportion of polar solvent to plant juice increased up to a ratio of 4 to 1, reaching a plateau at this level. Yields of concentrates obtained from alfalfa and white clover leaves were of the order of 32 and 15 g/kg respectively.

A parameter is introduced in order to evaluate various handling or cooling treatments for fresh foods. This parameter is obtained by assuming that food quality is greatly affected with storage time and temperature. A procedure is developed to estimate the parameters of initial cooling treatments for refrigerated food.