Accelerated Fermentation Process for the Manufacture of Fish Sauce Using Histidine

Addition of histidine accelerated hydrolysis of fish protein during fermentation in the manufacture of fish sauce and after 4 mo fermentation yielded a product typical of traditional fish sauce. The liquefaction rate of the histidine-treated sauce was faster than that of the control. The degree of hydrolysis was much greater in the histidine-added sauces than in the control. Most amino acids were higher in the histidine sauces compared to commercial patis sauce (as reference). Addition of histidine to the fish mixture during fermentation did not increase the histamine content of the sauces.     

SCREENING OF RESISTANT TRIACYLGLYCEROLS TO THE PANCREATIC LIPASE AND THEIR POTENTIALITIES AS A DIGESTIVE RETARDANT

A gradual retarding of lipid digestion and absorption might contribute to preventing the visceral fat accumulation and obesity in humans. The lipolysis rates of different triacylglycerols (TAGs) by pancreatic lipase in vitro were studied in order to find suitable components as a retardant for lipolysis. Several TAGs containing longer acyl chains than stearic acid or containing unsaturated fatty acids whose double bonds are located closely to the carboxyl group like petroserinic and γ-linolenic acid showed significantly lower lipolysis rates as compared with triolein (OOO) control. Most of these resistant TAGs contributed to decelerating the lipolysis rate when replaced at 10% into the OOO control. Especially, 1-behenoyl-2,3-dioleoyl- rac -glycerol (BOO) was comprehensively thought to be a suitable TAG as a digestive retardant among them. Each 10% replacement of edible oils by BOO gave 15% to 30% reduction of the lipolysis rate in vitro . Resistant TAGs that are able to melt or solubilize into liquid oil at body temperature have some potential as a digestive retardant for lipids.

PRACTICAL APPLICATIONS

Visceral fat accumulation and obesity in humans are thought to be correlated with the rate of lipid digestion and absorption. The entire rate of lipid absorption is controlled by their partial replacement with some digestive retardant. Resistant triacylglycerols may have some potential as a digestive retardant of lipids. Results of the present study propose a new fat system for foods with antiobesity effect.     

Oxygen Effect on Volatile Acids Formation During Fermentation in Manufacture of Fish Sauce

Volatile acids of aerobically and anaerobically fermented fish sauces were investigated using GC and GC-MS. There was no significant difference in pH values of the two types of sauces. Volatile acids found in the aerobically fermented sauce had concentrations significantly higher than the anaerobically fermented one. Sensory evaluation revealed that the aroma of the anaerobically fermented sauce was a little sweet, less acidic and less rancid than the aerobically made sauce which was sharp, and cheesy. Thus, fermentation under anaerobic condition altered the aroma quality of the sauce during manufacturing, yielding an acceptable product.     

MOLECULAR PROPERTIES OF POST-MORTEM MUSCLE. 9. Effect of Temperature and pH on Tropomyosin-Troponin and Purified α-Actinin from Rabbit Muscle

SUMMARY– A study was done on the effects of in vitro storage of purified α-actinin, troponin, tropomyosin, and the tropomyosin-troponin complex on the activity of these protein fractions in the ATPase and superprecipitation assays. Storage was done at various combinations of temperatures between 0 and 40°C and pH values between 5.7 and 7.0. Even after 40 hr of storage, activities of purified tropomyosin and the tropomyosin-troponin complex were not affected by any combination of temperature and pH included in this study, but activities of purified α-actinin and troponin were almost completely lost after 16 hr at 40°C and pH 5.7. Storage for 40 hr at low pH (5.7) and low temperatures (0°C) did not affect the activity of either α-actinin or troponin, but 40 hr of storage at high temperatures (40°C) and neutral pH caused some loss in activity for both these proteins. This loss of activity caused by 40°C, pH 7.0 storage was much more noticeable in the case of troponin than in the case of α-actinin. Storage periods of 40 hr or longer were required before any loss of α-actinin activity could be detected at pH 7.0 and 40°C. Since most meat animal carcasses are chilled soon after exsanguination and attain muscle temperatures of 25°C or lower before the pH falls below 6.2, it is probable that α-actinin and tropomyosin-troponin activity remain almost unchanged in meat handled through normal market channels. However, myofibrillar tissue in those porcine animals whose musculature undergoes a very rapid post-mortem decline in pH so that values of 5.7 or less are reached while muscle temperatures are still 37°C or higher may lose much of its α-actinin and tropomyosin-troponin activity during the first 24 hr post-mortem.     

A case study on measuring inspection performance for inspection job design

In the quality control system, most of the information for decision making and problem solving can be obtained by inspection activities. Therefore, the inspection work should be organized to maximize meeting the quality objectives. It has already been publicized that data obtained from measurement of inspection performance will supply an effective basis for assessment and design of the inspection station and inspection job. This paper is intended to report on a case study of measurement of inspection performance conducted for the assessment and design of an inspection job in a manufacturing company. Quality control specialists selected three groups of items having representative deficiencies under routine inspection, inspected as inspection job samples. They had individual inspectors inspect each sample to obtain data consisting of the rate of defects detected out of all the defects, and the proportion of erroneous findings in the total number of findings by each inspector. Thus they identified many problems in the inspection job to be corrected to enhance the inspection accuracy. Appropriate action was taken to remedy the situation. In the first place, the inspection job was redesigned. In the second, the method of training inspectors was reviewed and modified. As a result, the probability of defects passing the inspection undetected was greatly reduced.     

Oxygen-Sensor-Based Simple Assay of Histamine in Fish Using Purified Amine Oxidase

Oxygen consumption was measured by an oxygen sensor after addition of purified fungal amine oxidase to fish extracts. The oxidation of histamine to imidazoleacetaldehyde proceeded stoichiometrically. Based on the equimolar relationship between histamine and oxygen consumption, histamine was determined selectively by the oxygen sensor. Neither sample pretreatment removing interfering materials nor daily calibration by histamine standard was required. Histamine contents in scombroid fish were determined rapidly with good accuracy. AOAC and oxygen sensor methods showed a very high correlation (r=0.999, n=6).     

Overall Quality and Sensory Acceptance of a Lysine-Fortified Fish Sauce

The feasibility of making fish sauce with added lysine was studied. A difference was found in quality of the volatile compounds detected from the control and from the lysine-added samples. High concentration of lysine did not significantly affect acceptance due to aroma but reduced acceptance of flavor and color. Addition of lysine could feasibly increase protein level of fish sauce. Sensory evaluation in terms of overall quality showed that addition of up to 2.0% lysine was quite acceptable.