Most dried food is produced by traditional hot-air drying methods, by which the fresh flavour, natural texture and color are liable to be lost or changed. Case hardening and thermal denaturation can also occur, which decrease the rate of drying and prevent the rehydration of dried meat. An important quality criterion for such dried meat products is rehydration capacity; the drying process should not affect water absorption capacity of the meat. We dried minced raw chicken, molded into 4 thin pieces (130mm×130mm, thickness 3mm, weight 0.07kg/piece), at various levels of microwave power and at various air temperatures. The samples were immersed in an aqueous solution of 2% NaCl at 10°C after drying, and their rehydration was examined. We obtained dried chicken of quality with minimum heat damage by choosing appropriate drying conditions. Forced draft drying at 80°C, gave almost the same dehydration curve as did microwave-assisted forced draft drying at 0.14kW/kg microwave power and 60°C. However, the proteins of meat dried in this way were obviously damaged in drying, and on reconstitution, only a fraction of the moisture it originally contained was absorbed. The optimal conditions were; microwave power 0.14kW/kg, air temperature 60°C, and drying time 2 hours. On reconstitution, the meat dried in this way returned to a state that closely resembled raw meat, which will be useful as an ingredient in various meals.

View full abstract

The effects of chitin hydrolysates made from shell of crustaceans (King crab, Paralithodes camtschatica and Japanese fan lobster, Ibacus ciliatus) and cartilage of cephalopods (Spear squid, Doryteuthis bleekeri) on the denaturation and the state of water of lizard fish myofibrillar protein (Mf) during drying process were investigated. Five grams (dried matter) of each chitin hydrolysate was added to 100g of Mf, and water activity (Aw) of Mf and Mf Ca-ATPase activity were examined during drying process. The addition of each chitin hydrolysate caused a decrease in Aw at the same moisture content, and an increase in the amount of multilayer and monolayer sorbed water obtained from a desorption isotherm curve as compared to a control (without chitin hydrolysates). The activity of Ca-ATPase of the control decreased rapidly, on the other hand, that of chitin hydrolysate containing groups lowered gradually in all Aw area. These results suggest that a chitin hydrolysate decreases Aw and suppresses Mf denaturation during dehydration process. The protection effect by chitin hydrolysates may be caused by stabilizing hydration water around Mf by added chitin hydrolysates.

View full abstract

As for the miso and the soy sauce, the soybean fermentation food which has long history in our country is typical. Peculiar flavor and a taste are given in the process of the fermentation, and such traditional foods form the taste culture which is characteristic of Japan. As for the soybean fermentation food done like this, an unpleasant taste such as astringency and an astringent taste is improved in the process of the fermentation. This is expected by the microorganism involved in brewing in the process of the fermentation having resolved the unpleasant taste element of the soybean. So, when the separation of the lactic acid bacteria was done from soybean fermentation food, it got the Streptococcus sp. S85-4 which had an effect on improvement of the unpleasant taste. It could get the fermentation food which had a refreshing taste when it went by using Streptococcus sp. S85-4 which separated through the fermentation of the soybean milk. And, fermented flavors such as acetoin and diacetyl wasn't recognized by using Streptococcus sp. S85-4. The effect on environment in the intestine was suggested because raffinose and stachyose, couldn't degraded by the separated Streptococcus sp. S85-4. Furthermore, soybean oligo-saccharide and isoflavon were thought to have the effect on prevention from many adults' disease because these beany component couldn't degraded in the process of the fermentation by Streptococcus sp. S85-4, too.

View full abstract

Pathogenic fungi contaminating bean sprout seeds (mung bean, black mappe) cause putrefaction to bean sprouts. Sterilization treatment should be done safely because it is usually consumed within 10 days after the treatment. We tried sterilization of bean sprout seeds using allylisothiocyanate (AIT), the food additive and the main flavoring component of Wasabi (Japanese horseradish) and mustard. We showed the following three things. (1) Growth of mung been sprouts was affected by dose of AIT, the product concentration multiplied by exposure time. It was showed that less than 600ppm·hr of AIT dose does not inhibit bean sprouts growth. (2) AIT exposure under 20ppm/RH 100% for 24hr inhibited damage caused by C. gloeosporioides, A. alternata and F. oxysporum with no influence on bean sprouts growth. (3) It is desirable to use chloride treatment and AIT treatment together. AIT treatment could inhibit chloride resistant disease, but AIT treatment alone was not successful for some disease for which chloride treatment was effective.

View full abstract

Chlorella has long been considered to be a healthy food for hypercholesterolemic patients. However, its immediate effect on serum lipid levels has not yet been sufficiently elucidated clinically. We therefore evaluated the serum cholesterol lowering effect of Chlorella, cultured under heterotrophic conditions with glucose as a carbon source, in patients with mild hypercholeste-rolemia. Twenty patients with type II_a hypercholesterolemia were divided into two groups with similar clinical demographics. Eleven patients were each given 3g of Chlorella daily for 3 months (Chlorella group), while nine patients were not (Control group). In the Chlorella group, serum total cholesterol and LDL-cholesterol levels were significantly decreased. The Apo A-I level in serum was increased and atherogenic index (Apo B/Apo A-I) was decreased compared to that before Chlorella ingestion. Improvements in general physical conditions were also observed based on the results of a questionnaire survey. No appreciable side effects were seen during the study period. In the control group, no significant changes were observed during the study period in clinical findings except a temporary increase of the Apo B level in serum. These results indicate that daily ingestion of Chlorella has the potential to lower serum total cholesterol, LDL-cholesterol and atherogenic index in patients with mild hypercholesterolemia.

View full abstract

Actinidin, a cysteine protease in kiwi fruit, is known to affect the taste, allergenic properties and characteristics for food processing of the kiwi fruit. In six Actinidia deliciosa, five A. chinensis and two A. arguta cultivars, the actinidin concentration and the protease activity in the fruit juice were determined by quantitative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and spectrophotometric assay using L-pyroglutamyl-L-phenylalanyl-L-leucine p-nitroanilide as a substrate. In Abbott, Koryoku, Kuimi and Sinzan, both actinidin concentration and protease activity in the juice were significantly higher than those of Hayward, the most common cultivar of kiwi fruit. In contrast to these cultivars, protease activities in Rainbow red, Hort 16A and Kosui fruit juice were less than 7% of that of Hayward. In these three cultivars, little or no proteolytic effect on milk or pork myofibrillar proteins was observed. These results indicate that there is a wide range of varietal difference in actinidin content in kiwi fruit.

View full abstract

We examined the antihypertensive effect of Japanese taste seasoning containing γ-amino butyric acid (GABA) on mildly hypertensive, high-normal BP subjects and normal subjects. The extract of yeast was used as a source of GABA. In the first, the examination to determine the amount of optimal ingestion of GABA between 20mg/day and 40mg/day was conducted, and it was set in 20mg/day. Secondly, we conducted a trial to evaluate the antihypertensive effect of the Japanese taste seasoning containing 20mg of GABA (trial food). A randomized single-blind cross-over placebo controlled study was conducted on 48 subjects who are the worker at the same factory. The group of mildly hypertensive and high-normal BP subjects (SBP>130mmHg, DBP>85mmHg), and normal BP subjects were consisted of 17 and 31, respectively. All subjects were administered 15ml of trial food or placebo food for two weeks, and checked the blood pressure every day. The blood pressure was significantly lower after two weeks taking on mildly hypertensive and high normal BP group than before (6mmHg/SBP, 4mmHg/DBP). The blood pressure of normal BP group was not changed. This result showed that the Japanese taste seasoning containing 20mg GABA is effective to control the blood pressure of mildly hypertensive and high-normal BP group. The any adverse effects were not observed on all subjects by taking this seasoning.

View full abstract

A non-destructive and continuous method to measure gelatinization of rice samples in a rice-water system during rice cooking process was examined. An aluminum pot and a lid of a rice cooker were used as two electrode plates, and changes in dielectric properties (capacitance: C, and dielectric dissipation factor: tan δ) of the samples in the rice cooking process were measured by a capacitance meter. Differential scanning calorimetry (DSC) was used to measure gelatinization enthalpy and to determine the degree of gelatinization. Dielectric loss was calculated from the dielectric properties, which changed as the rice cooking process proceeded. Thus, we defined the degree of gelatinization as the value obtained by integrating the dielectric loss with respect to time. The degree of gelatinization based on the dielectric properties was consistent with that based on the DSC. We concluded that the degree of gelatinization in the rice cooking process can be non-destructively and continuously determined by measuring the dielectric properties.

View full abstract

In order to assess the deterioration of frying oil, viscosity-increasing ratio and a new thinlayer chromatography method (3M PCtester) were evaluated with 46 daily oil samples from commercial delicatessens, restaurants, and frozen food makers producing fried foods. We also determined color, acid value, anisidine value, polymerized compounds, and polar compounds. The viscosity-increasing ratio was highly correlated with the amount of polymerized compounds (correlation coefficient: 0.980). The traveling distance in PCtester was also highly correlated with the amount of polar compounds (correlation coefficient: 0.921). However, the acid value and the anisidine value were less correlated with the amount of polymerized or polar compounds. Polymerized compounds and polar compounds were determined usually by HPLC, which needs long time. However, the determination of viscosity-increasing ratio and the PCtester method are simple and rapid. Therefore, these methods in combination with acid value determination can be used as an easy comprehensive frying oil control method for business use. We recommend the viscosity-increasing ratio 15-20% and the PCtester traveling distance 24-27mm as the criteria for wasting deteriorated frying oil.

View full abstract

Packed tofu was prepared from the mixture of soymilk and whole blood or fractionated blood. Gel strength of the tofu increased by mixing whole blood and at the same time drain rate decreased. The red blood cell fraction had more remarkable effect than the plasma fraction. Little improvement in quality was observed when a hemoglobin solution was mixed. It was suggested that the improvements in gelling properties were caused by protein-protein interactions or that some materials other than proteins play an important roll in gel formation. No blood proteins were detected in the drain from the tofu, suggesting that blood proteins contribute for forming a gel network.

View full abstract