A Study of an Aroma Extraction Method and Evaluation of the Aroma Extract Contribution to the Palatability and Reinforcement Effect of Dried Bonito Using Mice

Abstract

Humans have a strong preference for sugars and fats, and they recognize dishes and sweets rich in sugars and fats as palatable food. Rodents also have a strong preference for sugars and fats. Two-bottle choice tests using sugars and fats have been reported to show not only their high palatability but also a reinforcement effect (1,2). Conditioned place preference (CPP) tests have been widely used to determine the reinforcement effect of a given sample (3).Tastes considered palatable by humans are not limited to sugars and fats. For example, broths, which contain taste components such as flavors and distinctive aromas extracted from plants and animals, are indispensable for enhancing the taste of dishes. Dashi (broth) made from katsuobushi (dried bonito) is a very basic and indispensable element in Japanese cuisine. Although it is not rich in sugars or fats, Japanese cuisine has provided satisfying meals by fully utilizing the unique aroma and taste of katsuodashi (dried bonito broth). Therefore, it is important to re-evaluate the value of Japanese cuisine that provides satisfaction with low calories.Katsuobushi (dried bonito) is made from katsuo (Skipjack tuna, Katsuwonus pelamis) by the following processes: cutting raw katsuo into pieces, boiling-aging, roasting-drying (smoking and drying over a smoking wood fire), molding, mold inoculation, and sun drying. In this process, the intermediate product from the roasting-drying step is called arabushi. Because tar from the roasting-drying step is deposited on the surface of the arabushi, the surface is shaved during the molding step and the powdery shavings are called G powder. The product from the molded arabushi that is subjected to repeated cycles of mold inoculation and sun drying steps is called karebushi. Both arabushi and karebushi are widely marketed as katsuobushi. A hot water extract of shavings of arabushi or karebushi is called katsuodashi (dried bonito broth), an indispensable broth in Japanese cuisine. Other fishes including maguro (yellowfin tuna, Thunnus albacares), goma-saba (spotted mackerel, Scomber australasicus), souda-katsuo (bullet tuna, Auxis rochei), and katakuchi-iwashi (Japanese anchovy, Engraulis japonicus) are processed in similar ways for use in making broths.Kawasaki et al. and Ackroff et al. found a preference for dried bonito broth in two-bottle choice tests using mice (4, 5). Furthermore, Kawasaki et al. performed CPP tests and found a significant reinforcement effect for a dextrin solution containing natural dried bonito broth (BD), but not for a dextrin solution alone (6). In addition, they analyzed taste components in natural Summary Japanese cuisine has provided satisfying meals by fully utilizing the characteristic aroma and taste of katsuodashi (dried bonito broth), though it is not rich in sugars or fats. Katsuodashi is a very basic and indispensable element in Japanese cuisine, and is a hot water extract of katsuobushi (dried bonito). It has been reported that a dextrin solution containing natural dried bonito broth has a si...

The contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect

“…The trimmings from the smoked bonito during shaping (G flour) contain abundant tar components, and the solution with aromatic extract from the G flour did not induce significant preference. 7) Based on this, the contribution of phenolic compounds in 28re to the preference may be low, and other aromatic components derived from lipid oxidation are possibly responsible for the preference. However, further verification is required.…”

“…As previously reported, the test solution with arabushi sCO 2 extract evokes preference and a reinforcement effect. 7) We have conducted the present experiments to elucidate the compounds that are contributed to the preference and reinforcement effect. Arabushi sCO 2 extract contains volatile components as well as low volatility components with a high boiling point.…”

“…Arabushi sCO 2 extract was prepared as described in the previous report. 7) The experimental scheme is shown in Fig. 1.…”

“…Amitsuka et al prepared various extracts using different types of dried bonito and methods. 7) Obtained extracts were added to dashi-taste solutions and subjected to two-bottle choice tests. As a result, a solution containing aroma extract obtained from arabushi (a type of dried bonito) by supercritical CO 2 extraction method (sCO 2 ) was preferred.…”

“…These findings indicate that the sCO 2 aroma contains components contributing to the preference and reinforcement effects. 7) This study aims to elucidate the components contributing to the preference and reinforcement effect associated with dried bonito and to apply findings from the study in daily life in the future. We fractionated and analyzed the aromatic components of the arabushi…”