In order to obtajn a suitable method for defrosting, effects of defrostjng temperature and defrosting velocity on the quality of defrosted whale meat were investigated by various methods, such as air defrosting at 0°, 10°, 20°, 30° and 50°C and high frequency defrosting.
Some changes occured in the defrosted meat by raising defrosting temperature. Ratios of weight reduction and free drip increased and Young's modulus and maximum strain energy measured with a Tensilon decreased and slope of stress-strain curve lowered. Under the microscopic observation of the defrosted meat, some damages in muscular tissue and in meat fiver which was defrosted at high temperature such as 30° and 50°C were shown. The close reverse correlation was observed between Young's modulus and ratio of free drips. Total nitrogen contents in free drip from the meats defrosted at 0°, 30° and 50°C were higher than those defrosted at 10° and 20°C.
It was recognized that these facts were caused from the difference of the time taken for the zone of maximum ice crystal in each defrosting temperatures. Defrosting at 10° and 20°C, followed by the high frequency defrosting gave best results in quality, but some defects such as uneven defrosting were shown.

View full abstract

Heat penetration into food-simulated materials packaged with the laminated flexible films during heat processing by using the steam-and-air retort was investigated.
Appreciable difference has not been found among the values of heat penetrating-rate parameter, f, obtained with packages using two types of laminated films (12μ polyester-50μ polyethylene and 12μ polyester-3μ foil-50μ polyethylene) and at different processing temperatures from 105 to 120°C.
Surface coefficients of heat transfer, h, have been estimated from the f-values obtained with infinite slab type packages. The estimated coefficients are 1.13±0.05×10^-2 and 0.826±0.117×10^-2 cal cm^-2sec^-1 deg^-1 for the samples processed under 65-90% and 55% steam ratios, respectively.
The f-values of the finite slab type packages at the steam ratio of 65-90% have been found in good agreement with the values calculated from the theoretical equation by using h-value estimated in the infinite slab experiments.

View full abstract

The extraction rate equations were derived for the mixture of several consistuents having different diffusion constants. It was found that the curve fitting and Laplace inverse transformation method were successful to estimate the distribution function of diffusion constants from the results obtained as ratios of extractable material content to the initial extractable material content vs. time. As it requires so much efforts, we simplified the method by assuming some approximations about the distribution function mentioned as follows.
By choosing the normal distribution as one of the approximation, the extraction rate equation was derived and discussed about the effects of standard deviation on the extraction, and figures were calculated to estimate the average value and standard deviation of diffusion constants.
The diffusion rate of fish oil were measured to determine the average value and standard deviation of diffusion constants and it was concluded that the effect of temperature on average value of diffusion constants D can be expressed as the known relation, D∝T/μ.

View full abstract

During the harvest season from 1973 to 1974, we examined the difference of juices qualities processed by In-Line juice extractor and Chopper pulper juice extractor.
The In-Line juice extractor was more usefull than the Chopper pulper juice extractor, but the yield of juice was less than that of another one.
The contents of pulp, flavanones and hesperidin in the juice (CPJ) processed by the Chopper pulper juice extractor were higher than that processed by the In-Line juice extractor (ILJ).
Essential oil content in ILJ was about twenty times of that in CPJ. This was marked difference in the qualities between ILJ and CPJ.
ILJ was more yellowish than CPJ.
The visual absorption of carotenoid pigments in petroleum ether extracted from CPJ was higher than that from ILJ.

View full abstract

Essential oil was recovered from the waste fluid in preparation of Citrus unshiu juice by InLine juice extractor at the periods from November, 1973 to March, 1974.
Physical and chemical properties and yields of essential oil were examined monthly. Gas chromatography was conducted to separate aromatic constituents and components were identified by comparison of retention times with authentic compounds. In gas chromatography, better results were obtained by DEGS column to separate low boiling components, and by PEG-6000 column to separate high boiling components.
Twenty six components were separated from essential oil by PEG-6000 column with program rate 4°C per minute.
The major aroma components were terpene hydrocarbones whose prominent component was d-limonene.
Terpene alcohols, sesquiterpene hydrocarbons and aliphatic aldehydes, were minor components.
From the result of sensory evaluation, it was recognized that the minor components correlate to the flavor of essential oil.

View full abstract

In order to establish the evaluation method of the appearance color of green tea, the correlation between the Hunter's color difference meter values and the sensory scores by expert panels were investigated using commercially packed green teas with three grades, high, medium and low.
The best correlation was obtained between the Hunter's a/b ratio value and sensory scores. The correlation coefficient between both values were about -0.9 or higher for each grade teas.
Furthermore, high and low grade teas were discriminated by the quality control diagrams made from two variables, Hunter's a/b ratio value and nitrogen content, which relates the appearance and flavor of tea, respectively.
From these results, it was concluded that the Hunter's color difference measurement method is usefull to grade green tea by the appearance color.

View full abstract

The ether extractS of steam distillate (distilled under acidifying with tartaric acid) of natural orange juices showed the similar pattern to benzoic acid in UV spectrum. The distillates were subjected to silica-gel column chromatography followed by gas chromatography.
Benzoic acid and acetic acid were identified by means of UV, IR and mixed melting methods. Contents of benzoic acid in Citrus Unshu and Citrus Natsudaidai peel were about 0.04 and 0.006% of fresh weight, respectively. From the results that recovery of the acids increased by treatment of alkali hydrolysis, it was suggested that they exist in the form of esters of high boiling substances. Existence of formic acid, isobutyric acid and n-butyric acid were tentatively identified by threshold volume of silicagel column and gas chromatography. The acids may contribute to off-flavor of concentrated juices of Citrus Unshu and Citrus Natsudaidai.

View full abstract

Hydrogen peroxide (H₂O₂) has been used for the purpose of sterilization of noodle in Japan, and the maximum amount of residual H₂O₂ permitted by the Food Sanitation Law is under 100ppm in Japanese noodle (udon). In this paper, the influence of H₂O₂ on loss of food additives in noodle and on some proteins (gluten and concentrated protein from rye or foxtail millet flour which were the materials reacting to reduce H₂O₂) were studied. Glycine and lysine were not decomposed by H₂O₂. Thiamine hydrochloride and dibenzoyl thiamine were decomposed in according to the additional amount of H₂O₂. By the treatments of steaming (100°C, 15min.) and storage (37°C, 7 days) of 20g of noodle-paste, additional glycine (1.1%) and H₂O₂ (850ppm) induced 2.3ppm of folmaldehyde. The oxidation of the proteins above-mentioned by H₂O₂ might be considered to be negligible, because the amount of oxygen-gas evoluted by the reaction of these proteins with H₂O₂ was equal to the calculated amount from the H₂O₂ decomposed by each protein. Composition of amino acids of proteins in noodle, which was stored for 3 days at 37°C after addition of H₂O₂ (0-850ppm) and steaming (100°C, 15min.), was analyzed by an automatic amino acid analyzer. The treatment of H₂O₂ gave almost no influence on the composition of amino acids.

View full abstract

Frozen-thawed white sauce tends to degrade remarkably than fresh one.
The degrees of degeneration were examined by organoleptic tests and rheological measurements.
The sauces were frozen and stored at -25--28°C. After 7 days, they were thawed in an icebox below 5°C and viscosity, thixotropic properties and volume of released water were measured immediately.
Rheological changes were perceived distinctly in relating to degeneration as shown by organoleptic tests of frozen-thawed sauce.
Additions of lecithin, sodium alginate, carageenan, or the mixture of these three additives at the level of 0.1%, showed no effect on prevention of changes.
Addition of sodium alginate at the level of 0.1% was partly effective on improvement of properties.

View full abstract