Changes of the Na-, Ca- and Mg-content in the aqueous pectin solution, prepared from radish root and placed in a dialyzing membrane tube, by soaking in sodium chloride solutions was investigated. Infrared spectroscopy and atomic absorption spectroscopy revealed that most of the carboxyl group in the pectic substance was easily changed into the Na-salt and both Ca and Mg in the pectin were replaced by Na of sodium chloride. From these results, it is assumed that the leak of Ca and Mg from the crude cell wall during salting of radish root for pickles manufacture, as reported in the previous paper, may be caused by the exchange of Ca and Mg with Na of sodium chloride, and also by the change of carboxyl group into Na-salt, in the tissue pectin.

View full abstract

The changes in flavor components of cooked cured pork loins during the process using the traditional pickle curing method(TPCM)or the pickle injection method(PIM)were investigated by chemical anaiysis and products produced by both methods were compared by sensory tests. Pork loins were cured for 13 days in the TPCM, while pork loins were injected with 15% pickle solution in weight ratio and then massaged in the PIM. Both were then dried and smoked. The results obtained were as follows. (1) ATP related compounds degraded during the curing period. Apparent changes were clearly noticeable in the TPCM treated loins, while they were minutely detected in the PIM treated loins. Therefore the composition of ATP related compounds in products produced by the TPCM was different from that produced by the PIM. (2) The free amino acids contents except glutamine, increased during the curing period. The changes were clearly evident in the TPCM than in the PIM. (3) Succinic acid content in the TPCM clearly decreased than in the PIM. (4) Changes in sugars and nitrite radical contents were similar in both methods. (5)The panels of investigators concluded, based on sensory tests, that products produced by the TPCM were better than those produced by the PIM.

View full abstract

The preparation and regeneration of mycelial protoplasts from Flammulina velutipes and Pleurotus ostreatus were examined. With both F. velutipes and P. ostreatus, the age of mycelium remarkably affected the isolation of protoplasts. High yields of protoplasts (6.7×10⁷ cells/ml in F. velutipes and 3.8×10⁷ cells/ml in P. ostreatus)were obtained from young mycelium (2-3 days culture). Older mycelium(7-8 or 20-24 days culture) gave low yields. The components of a liquid medium showed a significant effect on the yield of protoplasts. In the case of both mycelium, the highest yield of protoplasts was obtained from the mycelium cultured on OS(Onion-soysauce)medium. The most suitable combination of commercial enzymes for digesting cell walls of mycelium was cellulase "ONOZUKA" RS (or R-10), Zymolyase 5000, chitinase and β- glucuronidase. In the case of both F. velutipes and P. ostreatus protoplasts, the development of hyphae was observed after 2 days on the solid media, but only after 5-10 days in liquid media. Three characteristic patterns could be observed for the regeneration of protoplasts. In the first, one or more germ tubes were directly produced from spherical protoplasts. Regeneration of this type occurred most frequently. In the second, some protoplasts formed a short chain of "yeast-like cells". In the third case, several modified "bud-like cells" were formed giving rise to germ tubes. The protoplasts cultured on the OS solid medium showed the highest regeneration frequency.

View full abstract

Nickel papain was immobilized by the use of various parts of citrus fruit. The pectic support prepared from the mixed materials of citrus albedo and segment cover had properties superior to those of the others in 0.1M phosphate buffer, pH6.8. However, the other buffer systems are recommended for the immobilized enzyme reaction at high temperatures. Properties of nickel papain were similar to, or superior to those of mercury papain reported in the previous paper. It was observed that the activity of immobilized nickel papain was also maintained at high levels after 25 times repeated use as mercury papain.

View full abstract

The research was carried out to clarify the seasonal variation of air borne fungal flora in a small scale of confectionery. In June and December, 1981, air borne fungi were collected by means of a pin hole sampler for ten continous days. The fungal content was 0.69±0.50 cfu/l of air in the summer, and was 0.12±0.06 in the winter. Although the main air borne fungi were Penicillium, Cladosporium, Aspergillus and Rhizopus, their appearance varied seasonally. Penicillium was the most predominant and occupied 70% of the air borne flora in the summer. In winter, Penicillium decreased remarkably, and Cladosporium and Aspergillus increased to a considerable extent. The flora in this time consisted of 42% Penicillium, 24% Cladosporium and 14% Aspergillus. Furthermore, it was shown that the fall-out flora was somewhat different from the floating flora in the air. While, Penicillium and Cladosporium sedimented onto a plate surface predominantly in the summer, the fall-out of Aspergillus increased significantly in the winter.

View full abstract

The relationship between yeast population and volatile components including alcohols, esters and aldehydes prouced in fermenting must and aged wine was investigated by using gas chromatography for the quality control of wine making. Gas chromatographic analysis using 10% polyethyleneglycol 20 M proved that the volatile components in grape juice were ethyl alcohol (400.3 ppm) and trace quantity (less than 1 ppm) of n-propyl alcohol, isobutyl alcohol and furfural. On the other hand, those found in the fermenting must were ethyl alcohol (4721.3 ppm), acetaldehyde (139.4 ppm), furfural (23.0 ppm), isoamyl alcohol (21.3 ppm), isobutyl alcohol (18.1 ppm), ethyl caprylate (16.4ppm), n-propyl alcohol (7.2 ppm) and trace quantity (less than 1 ppm) of ethyl acetate, ethyl caprate, ethyl laurate and p-phenetyl alcohol. A positive correlation was found between yeast population and volatile components in fermenting must. The correlation coefficients between the yeast population and isoamyl alcohol, furfural, n-propyl alcohol, isobutyl alcohol, ethyl caprylate, acetaldehyde were 0.837, 0.838, 0.848, 0.866, 0.876 and 0.887, respectively.

View full abstract

The effects of mixing temperature, fermentation time, punching of dough and final proofing time on the quality of final products of white bread prepared by the straight dough method were investigated using the experiment of orthogonal L₈ design. The pH value, total titratable acid ity(T. T. A.), specific volume and residual sugar of the products were measured, and the following results were obtained. The pH value was affected by the mixing temperature and the fermentation time. The T. T. A. value was affected by the final proofing time, fermentation time and mixing temperature. Specific volume was also changed by punching of the dough. The amount of residual disaccharide in the bread was affected by mixing temperature, fermentation time and punching of dough.

View full abstract

The effects of the combination ratio of materials(sugar, skim milk powder, eggs and margarine)in the production of white bread by the straight dough method were investigated using the experiment of orthogonal L₈ design. The pH value, total titratable acidity(T. T. A.), specific volume and residual sugars of the products were measured, and the following results were obtained. The pH vaiue and T. T. A. of the products were changed by the addition of skim milk powder and eggs which produced a buffer action, but were not affected by the addition of sugar which had a fermentation property.The addition of margarine affected only the T. T. A. value of the product. The specific volume of the product was not changed by the amount of sugar, margarine, or the addition of skim milk powder and eggs in the procedure of white bread production when the usual combination ratio of the materials were used. The amount of the residual monosaccharide in the products was increased with the addition of sugar and the residual disaccharide was increased by the addition of skim milk powder.

View full abstract