The authors reported in the previous paper that the ultrastructure, observed by transmission electron (TE) microscope, of heated and frozen chicken and duck albumen was changed evidently by removing of ovomucin. Here differences between TE micrographs of chicken and duck ovomucin were observed. Ovomucin of fresh chicken and duck egg albumen was precipitated by dilution (1: 4) or with 1N HCl (pH 5.50) and the precipitate was washed thoroughly with 2% KCl and then water. Precipitation and washing were carried out by centrifugation (2850×20min). In the washing process, all floating materials separated from ovomucin was discarded. Total nitrogen, hexose and hexosamine of the prepared dilution-ovomucin and acid-ovomucin were determined. Washed wet ovomucin was heated in water at 95-98°C for 20min. Materials were frozen at -20°C and thawed at room temperature (20-25°C). Micrographs of ovomucin was taken by the use of TE microscope operated at 75kV. In micrographs of chlcken ovomucin electron dense fibrous figures were observed. Micrographs of duck ovomucin Showed characteristic electron dense figures which were composed of loosely condensed clumps or patches. These figures in chicken and duck ovomucin were almost unchanged in heating or freezing process. The characteristic figures of duck ovomucin are more evident in dilution-ovomucin than in acid-ovomucin. In all materials observed here protein matrix seemed to be condensed into electron dense clumps or fibers by heating or freezing.

View full abstract

Alcoholic fermentation of raw Satsuma mandarin peel was carried out by a nonconventional method. The enzymes used for liquefaction and saccharification were hydrolases of Aspergillus niger cultured in the medium containing Satsuma mandarin peel as substrate. A 5.2g of ethanol was produced from 100g of raw material in a day. Distillate obtained from raw citrus peel gave out fragrance originated from volatile oils, and high boiling compounds such as d-limonene, citronellal, linalool and α-terpineol were detected. The crude protein content of residue after alcoholic fermentation was 19.4%. Therefore, alcoholic production from peel wastes might be valuable to convert them to commercially valuable products such as liquor and animal feed.

View full abstract

Lipid and fatty acid composition of total lipids in seeds and endocarps of bayberries (Myrica rubra SIEB. et ZUCC.) were studied by means of silicic acid column chromatography, thin-layer chromatography and gas-liquid chromatography. Three cultivars of barberry used as oil material were 'Moriguchi', 'Tateishi' and 'Kohgyoku'. The results obtained were as follows. (1) Total lipid content were 46.2-50.1% (50.5-54.7% in dry matter) in seeds and 0.4-0.8% (0.5-0.9% in dry matter) in endocarps. (2) Neutral lipid content in total lipids were 96.5-97.1% in seeds and 66.2-70.3% in endocarps. While, glycolipid and phospholipid content in total lipids were 2.5-2.6%, 0.3-0.9% in seeds and 22.4-24.5%, 6.6-9.3% in endocarps, respectively. (3) In both seeds and endocarps, the main lipid in neutral lipid was triacylglycerol (TG, 92.9-95.5% in seeds, 73.9-77.4% in endocarps). (4) The main lipid in glycolipid in both parts were acylsterylglucoside, monogalactosyldiacylglycerol, while the main lipid in phospholipid were phosphatidylcholine and phosphatidylserine. (5) The main fatty acid in the four lipid fractions (TL, NL, GL and PL) were 18:2, 18:1 and 16:0 acids in seeds and endocarps. However, there was a little difference between two parts and among four lipid fractions.

View full abstract

The use of Saccharomyces cerevisiae (for sake, wine and bread etc.) for the manufacture of soybean protein curd from soybean milk was investigated. S. sake coagulated soybean milk easily by culture on 30°C, but under the same conditions, it did not coagulate milk and skim added 2% glucose. The compositions of soybean curds which were obtained by use of sake, wine bread yeasts were similar to tofu, but those curds had fermented flavour instead of beany flavour. Protein and fat yields in curds were approximately 86-88% and 100%, respectively. During the process of fermentation, S. sake formed acetic acid, succinic acid and malic acid, and it was suggested that coagulation was caused by acidic products. In case of S. rouxii, coagulation of soybean milk was slower than that with S. cerevisiae.

View full abstract

Treatment of waste-water discharged from a dried-bonito processing factory using yeast which was collected from wood sap and soil, was examined. Results obtained are as follows; (1) The waste-water contained a large amount of nitrogen compounds and a small amount of carbohydrates. (2) Among 1, 670 yeast strains tested, strain No. 48 showed the highest ability to utilize organic substrances in the waste-water (3) This strain was identified as Hansenula anomala var. anomala. (4) The waste-water was treated by semi-continuous cultivation of the strain No. 48, in which two thirds of the waste-water was exchanged a day. The waste-water contained 24600ppm of COD and 3610 ppm of nitrogen, and after the treatment, they were reduced to 6, 450ppm and 1050ppm, respectively.

View full abstract

A computer-aided technique was used to design a packaging system to keep dried laver, Porphyra yezoensis. Loss of chlorophyll a in dried laver could be described by first-order kinetics at all water activities tested. A linear relationship was obtained between the logarithm of the first order rate constant and moisture content. An empirical equation proved to be suitable to express the moisture sorption isotherms of dried laver and of desiccant. With these results, mathematical models to evaluate the moisture and chlorophyll a changes of the packaging system which included an enclosed desiccant was developed. Simulated values obtained by the proposed models gave a close approximation to the actual values.

View full abstract

The fermented product of Antarctic Krill so called shiokara was prepared by the addition of 5% sorbitol (method 1) or 5% ethanol (method 11) to the usual method of small shrimp-shiokara processing. Changes of volatile components of the modified method 1 during fermentation were studied by simultaneous distillation and extraction with NICKERSON'S apparatus. On the other hand, the collection and analysis of the headspace volatiles from method II by Tenax-GC was carried out. Twelve pyrazines, 8 aldehydes, 7 alcohols, 7 ketones, 2 thiazoles and 10 others were identified in sample of the modified method 1 by GC and GC-MS. Among the fermented products from the modified method and the usual method, sensory difference was confirmed and quantitative difference was observed on gas chromatograms, which were considered to be desirable flavor of the fermented product by the modified method.

View full abstract

A bitter peptide fraction from the peptic hydrolysate of a fish protein concentrate was treated with crystalline wheat carboxypeptidase. The bitterness of the bitter fraction lessened with an increase in free amino acids. The enzymatic hydrolysate obtained from the digest of the bitter peptide fraction by wheat carboxypeptidase was chromatographed on Sepandex G-15 and separated into three fractions: high molecular weight fraction, dipeptide fraction and free amino acid fraction. Glutamic and aspartic acids costituted 50% of all amino acids in the dipeptide fraction. When the release percentage of total free amino acids was approximately 38%, those of hydrophobic amino acids with a Δf value (cal/mol)>1600 were 40-84% except for proline, and amino acids with a Δf value<1600 had a tendency to be released less than hydrophobic amino acids. The wheat carboxypeptidase seems to eliminate bitter taste under the cooperative effects of the selective release of hydrophobic amino acids and the formation of acidic dipeptides from the bitter peptides.

View full abstract

The free amino acids, organic acids and aroma components of the Chinese vinegars were examined comparing with those of Japanese rice vinegar. The Chinese vinegars were rich in the amount of alanine, glutamic acid, lysine and leucine and comparatively less in that of tryptophan, histidine, proline and cystine. The amount of these amino acids were approximately ten times of that of Japanese rice vinegar. Lactic acid was the most dominant in amount followed by pyroglutamic acid among the organic acids except acetic acid in Chinese vinegars. Among the aroma components of Chinese vinegars, n-propyl alcohol, iso-propyl alcohol, iso-butyl alcohol, acetoin, diacetyl, n-butyl acetate, iso-amyl caprate, ethyl acetate, n-propyl acetate and furfural were in high level. In a sensory test, the stimulus smell of acetic acid was comparatively less but burning smell (burning taste), bitter and astringent taste were felt obviously. The difference of the amount between Chinese and Japanese vinegar seemed to be caused by the difference of the materials and making methods.

View full abstract

The test solution for estimating ascorbic acid (AsA) in the fruit of Satsuma mandarin (Citrus unshiu Marc.) was prepared in the usual procedure except for containing the destruction of ascorbate oxidase in the fruit by the heating with micro wave and the removal of an interfering factor against total AsA analysis by the adsorption Japanese acid clay. Total AsA, AsA and dehydro AsA in the test solution were determined by the difference spectral method and the content of these compounds was surveyed at different growing stages of the fruit. Total AsA (mg%) in the peel of the fruit was comparatively high in an early growing stage (late in June) and then decreased toward the middle of August, when it showed a minimum value. Afterwards, the compound increased to the same level as a young fruit until the last stage of development. The amount of total AsA calculated per fruit slightly increased by late August and markedly rose after this period. This suggests that the compound may be stored in the peel as the fruit was ripened. The tendency in the change of its amount in the pulp was similar to that in the peel. Total AsA in both peel and pulp of the fruit was mostly AsA. Dehydro AsA was rarely found in developing fruits.

View full abstract

White crystal or sediment that often found in Shiokara made of firefly squid (Watasenia scintillans, BERRY) during the refrigeration causes unpleasantness for consumers. Amino acid analysis and microscopic study proved that the crystal or sediment in Shiokara is due to the crystallization of tyrosine. Tyrosine contents, as a free amino acid, in mantle, arm, liver and ovary of firefly squid were 26, 23, 237 and 45mg/100g, respectively. Tyrosine in the liver of firefly squid was thought to be the major cause of the white crystal or Sediment in Shiokara because of its solubility in cold water, 40mg/100ml at 17°C.

View full abstract