Antioxidant Capacity of Tempura Deep-Fried Products Prepared Using Barley, Buckwheat, and Job's Tears Flours.

Tempura is a dish of battered and deep-fried foods, and wheat flour is typically used; however, barley, buckwheat, and Job's tears have an antioxidant capacity. This study investigated whether replacing wheat flour with flours from these three crops in tempura affects the antioxidant capacity and deterioration of frying oil. Radical scavenging activity and polyphenol content of tempura were measured by chemiluminescence-based assay and the Folin-Denis method, respectively. The peroxide value, p-anisidin value, acid value, and polar compound of the oil used in frying were measured as indexes of oil deterioration post-frying due to oxidation. Although the frying oil of barley showed higher p-anisidin value than that of wheat, the oil samples' deterioration level measured in this study was low. The antioxidant capacity and polyphenol content in the three flours samples were higher than those in wheat sample, with buckwheat producing the greatest values, followed by Job's tears, and then barley. Thus, deep-fried products prepared using the three flours demonstrated superior antioxidant capacity owing to the abundance of antioxidant components. Therefore, tempura can be enjoyed in a healthier manner by using batter prepared using those flours, and substituting wheat flour with the three flours can increase the antioxidant capacity of deep-fried products.

Radical scavenging activity of 'Nikogori' gelatin gel food made from head, bone, skin, tail and scales of fishes measured using the chemiluminescence method.

Head, bone, skin and tail mixed parts of yellowtail and bream, scales of bream and head of salmon which have nutritional values and are usually discarded were made into 'Nikogori' gelatin gel. They are not only a good source of protein but are also useful for elderly people with swallowing problems. Soy sauce, a traditional seasoning in Japan, was added to enhance the taste of 'Nikogori'. The rheological properties were examined by a rheometer and the peroxyl radical scavenging activity was measured by the chemiluminescence method. Sensory evaluation was also conducted employing 20 faculty members and students of the Laboratory of Cookery Science, Tokyo Kasei University, Japan to assess its acceptance. It was found that 'Nikogori' has peroxyl radical scavenging activity. Moreover, addition of soy sauce to 'Nikogori' enhanced the peroxyl radical scavenging activity. The rheological properties of 'Nikogori' and of the soy sauce added conformed to the standard set by the Ministry of Health, Labour and Welfare of Japan for elderly people with swallowing problems. From the data of the antioxidative activity and the sensory evaluation, the soy sauce-added 'Nikogori' was preferrable to that of the non-added one.

Effect of soy sauce on the antioxidative capacity of the gelatin gel food 'Nikogori' measured using the chemiluminescence method.

Oxygen-related free radicals have been suggested as a cause of aging and various diseases, for example, various cancers and rheumatoid arthritis. Because of this a radical scavenger as an antioxidant has been sought in many foods. 'Nikogori' gelatin gel from cooked fish is a traditional food in Japan. Recently, 'Nikogori' has been noted as a readily consumed food for the elderly and those with medical problems associated with swallowing. In this study we report that the 'Nikogori' gelatin gels made from the collagen in various meats have a high peroxyl radical scavenging capability as the antioxidative capacity using the chemiluminescence method and the order of the strength of antioxidative capacity (IC(50) value) was the Japanese common squid mantle meat (0.163%) > flatfish (marbled sole) meat (0.534%) > chicken wing meat (0.585%) > beef shin meat (0.655%) > yellowtail meat (0.659%) > chub mackerel meat (0.789%). Furthermore, when soy sauce was added to the 'Nikogori' gelatin gel, the antioxidative capacity increased markedly to 0.098% of IC(50) value of yellowtail, 0.165% of chicken, 0.182% of flatfish and 0.252% of chub mackerel.

Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

Antioxidative activity of the buckwheat polyphenol rutin in combination with ovalbumin.

Buckwheat flour is well known for its highly antioxidative ingredient, rutin. We have undertaken to examine alterations in the characteristics of rutin treated with various proteins. In this study, the radical scavenging activities of a rutin-ovalbumin complex were examined. Dissolved rutin hydrate and ovalbumin were combined and boiled in water for 10 min. In the resulting rutin-ovalbumin complex, a new high molecular weight peak was detected using gel permeation chromatography analysis, and an existing high molecular weight area of ovalbumin was observed to be increased by the addition of rutin. This suggested that ovalbumin molecules produce a complex through their interaction with rutin. Alkaline luminol chemiluminescence and electron spin resonance analysis revealed the formation of a rutin-ovalbumin complex that markedly enhanced the peroxyl, but not the hydroxyl, radical scavenging activity of rutin. Rutin also demonstrated antioxidative activity against hydroxyl radicals in a DNA protection assay. We therefore conclude that, compared with ovalbumin or rutin alone, the rutin-ovalbumin complex has improved antioxidative activities in the form of enhanced peroxyl radical scavenging activity and DNA protection from apurinic/apyrimidinic site formation caused by hydroxyl radicals.