Quality changes of cooking in hypobaric-packaged winter squash fruits were studied in relation to the differences of cooking temperature (70, 80 or 100°C) and degree of vacuum (30 or 100 Torr) in packaging. The cooking of winter squash fruits packaged under reduced and normal pressures with the usual cooking methods was investigated.
Winter squash fruits cooked at 100°C or 80°C showed no changes in surface colour.In Winter squash fruits which were packaged under reduced pressure at 100 Torr or normal pressure, browning occured with cooking at 70°C, but the browning did not occur in winter squash fruits packaged under reduced pressure at 30 Torr and in ordinary cooked winter squash fruits.
There were no appreciable differences between hardness of winter squash fruits and degree of vacuum during cooking at 70 or 80°C. In the cooking at 100°C, winter squash fruits remained harder with the lowering of the degree of vacuum while those packaged under normal pressure remained hardest.
The content of total ascorbic acid in winter squash fruits was kept higher during cooking at 100°C. On the other hand, at temperatures below 100°C, the content in hypobaric-packaged winter squash fruits showed higher than that in winter squash fruits packaged under normal pressure or in ordinary cooked winter squash fruits. The higher degree of vacuum, the lower became dehydroascorbic acid content at all the temperatures. Winter squash fruits cooked under normal pressure at 100°C showed highest value of dehydroascorbic acid among all the treatments.
There were no considerable differences between sugar content and degree of vacuum in packaged winter squash fruits. However, sugar content in ordinary cooking was lower when compared with that of the cooking of packaged winter squash fruits except when cooked at 100°C.
It is suggested that cooking at 80°C or higher temperatures and under reduced pressures is good for keeping quality of winter squash fruits.

View full abstract

Fresh sweet basil and purple basil were stored at 2°C and 20°C, and the effect of packing with sealed in polyethylene bag (30μm in thickness. PE), perforated polyethylene bag (PEf) and polyethylene stretch film (12, μm in thickness. PES) on the keeping quality of basils were studied.
The rete of weight loss was the greatest in PEf package with both kinds of basils at both temperatures, The freshness of sweet basil in PES, rapidly deteriorated to the limit of saling after storage for 6 days at 20°C. In PEf, it was deteriorated and reached to limit of saling at 7 days, while it was kept for 9 days at 20°C in PE package. The freshness of purple basil was kept for 9 days at 20°C in every kinds of package. At 2°C storage, the deteriorating rate of the freshness was faster than that at 20°C in every kinds of package and both basils. It was browning of leaves by chilling injury.
No difference of changes in ascorbic acid and free amio acid content was observed in both kinds basils and package.
The aroma evaluation score decreased with the progress of the storage time, and the rate was faster in PEf than that in PE at 20°C of sweet basil, but it was not observed in purple basil. The difference of decreasing rate on packaging method was not observed in both kinds of basils stored at 2°C. Chilling injury occurred severely under 10°C in sweet basil.
It was concluded that 12°C was the most suitable low temperature to prevent the chilling injury in basils. PE was the most effective to keep the quality of basils.

View full abstract

A new process for Worcestershire sauce using fermented mixture of vegetables and fruits juices is proposed. The experimental results on the preservation of fermented mixture of vegetables and fruits juices and the production of a new Worcestershire sauce using these fermented juice were as follows : (1) Tomato juice, supplemented with 8% (W/W) glucose, was fermented for 15 days at 22.5 ±2.5°C. The content of alcohol was reached to 7.5% (W/V) at 3rd day and thereafter maintained constant during fermentation period (15 days). The organoleptic properties of the fermented juice were maintained at higher level from the 3rd day. (2) The lactic acid fermentation of the mixture of vegetables juice [lettuce : cabbage : celery : onion : carrot=6 : 6 : 10 : 10 : 14 (W/W)] was also investigated and 84.8% of lactic acid was produced up to 3rd day and thereafter maintained constant during fermentation period (10 days) at 32.5±2.5°C. (3) The preservation of these fermented products was studied using both the alcohol fermented tomato juice supplemented with 8% (W/W) glucose and 3% (W/W) salt, and the lactic acid fermented mixture of vegetables juice which contained 9% (W/W) salt. The data indicated that these products could be kept for 15 days at room temperature (20-25°C) without any putrefaction. (4) A new type of Worcestershire sauce, using the fermented mixture of vegetables and fruits juice, was tested. Comparing the new Worcestershire sauce with those on the market, it was found that the former had high quality. The data from these experiments suggested that the introduction of fermentation process was effective for the production and the quality of a Worcestershire sauce.

View full abstract

This paper describes the relation between the activity of three phenol oxidases, such as monophenol oxidase (MPO), o-diphenol oxidase (_oDPO) and laccase (LA) in the tissues gill and pileus of shiitake (Lentinus edodes Sing.) mushroom and the browning of shiitake, and the difference of their activities between the strains Kanebo (C) and Meiji 1303-B (F). The effect of packaging with polyethylene bag on the changes in phenoloxidases activities and the browning of the mushroom was also observed.
The activity of MPO in gill was higher than that in pileus, but the activities of _oDPO and LA were higher in pileus. In strain F to brown easy, _oDPO and LA showed higher activities, MPO's activity rapidly raised at the time shiitake browned. In the shiitake sealed with polyethylene bag, these enzymes activities were inhibited considerably, but they increased with browning of shiitake packaged with perforated polyethylene bag. We suggest that the browning of shiitake was caused not only by the action of _oDPO, but also by the participation of MPO and LA.

View full abstract