Effect of intramuscular fat content on the sensory characteristics and dynamic flavor attributes of Japanese black cattle beef.

The intramuscular fat (IMF) in beef affects its flavor intensity and attributes, which have a significant impact on palatability. We conducted a sensory evaluation by descriptive analysis, Temporal Check-All-That-Apply, and a chemical analysis of 40 ribeye steaks from Japanese Black cattle to determine the relationship among IMF% and sensory characteristics including dynamic flavor attributes. The increased IMF% of Japanese Black cattle beef had intensified sweet and grilled/roasted flavors and reduced off-flavor, whereas excessive IMF% resulted in a decrease in water-soluble precursors of volatile and taste compounds including free amino acid and reducing sugars and weakened the flavor intensities. Beef with IMF% of approximately 40% exhibited strong and long-lasting sweet and grilled/roasted flavors represented by butter- and roasted nut-like, respectively, and a low perception of off-flavors represented by gamey, bloody, and grassy. These flavor attributes may be responsible for its high flavor intensity and overall evaluation score, whereas an IMF% of >55% lowered these scores. The excessive IMF% of beef may induce the less palatable sensory characteristics.

Enhanced lactic acid bacteria viability with yeast coincubation under acidic conditions.

The enhancing effects of yeasts on the viability of lactic acid bacteria (LAB) under acidic conditions were investigated. Meyerozyma guilliermondii, coaggregative with both LAB strains under acidic conditions, significantly enhanced the viability of Lactobacillus pentosus and L. paracasei in pH 3.0 lactic acid (LA) buffer at 10°C (p < 0.05). Non-coaggregative yeasts (Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Cyberlindnera saturnus) also significantly enhanced the LAB viability (p < 0.05), and physical contact between LAB and yeasts was not essential for the viability-enhancing effect, indicating that the coaggregation had no relation to the enhancing mechanism. Although yeast metabolites and LA assimilation had no enhancing effect, hydrogen peroxide (H2O2) decreased after yeast coincubation, and H2O2 elimination improved L. pentosus viability. H2O2 elimination alone did not sufficiently improve L. paracasei viability, but the addition of antioxidants was effective. These results suggest that the antioxidant activity of yeast increased the LAB viability under acidic conditions.

Japan Diet Intake Changes Serum Phospholipid Fatty Acid Compositions in Middle-Aged Men: A Pilot Study.

AIM: The Japan Diet nutritional education program effects on serum fatty acid compositions for prevention of atherosclerotic cardiovascular disease in middle-aged men brought up in the westernized dietary environment of modern Japan were examined. METHODS: Thirty-three men, 30-49 years of age, attended a nutrition education class and were recommended to consume Japan Diet volumes (more fish, soybeans and soy products, vegetables, seaweed, konjak, mushrooms, and unrefined cereals and less animal fat, meat and poultry with fat, sweets, desserts and snacks, and alcoholic drinks) for 6 weeks. Three-day weighted dietary records were kept, and fatty acid intakes were calculated. Serum phospholipid fatty acid compositions were examined. RESULTS: During the 6 weeks, fish, soy, and seaweed and/or mushrooms and/or konjak were consumed 1.0, 1.1, and 1.0 times daily on average, whereas daily fatty meat and poultry and sweet consumptions were 0.3 and 0.3, respectively. These changes were attributed to increased intake of n-3 polyunsaturated fatty acids (PUFAs) such as C20:5(n-3), C22:6(n-3), C18:4(n-3), and C20:4(n-3) and decreased intakes of all saturated fatty acids and unsaturated fatty acids such as C18:1 and C18:2(n-6). As to the phospholipid fatty acid composition, C18:0 decreased, whereas C15:0, C17:0, and C20:0 increased. Marked increases in C20:5(n-3) and C22:6(n-3) raised total n-3 PUFA from 10.30% to 13.20% along with n-6 PUFA decreasing from 33.92% to 31.16%. Despite decreases in C20:4(n-6) and C20:3(n-6), the C20:4(n-6)/C20:3(n-6) ratio used as an estimate of delta-5 desaturase activities increased and correlated positively with fish intake at completion of the intervention. CONCLUSIONS: The Japan Diet is effective for changing the fatty acids to an anti-atherosclerotic profile.The clinical trial registration number: UMIN000020639.

Effects of a Japan Diet Intake Program on Metabolic Parameters in Middle-Aged Men.

AIM: We conducted a pilot study to clarify the effects of the Japan Diet nutritional education program on metabolic risk factors for atherosclerotic cardiovascular disease in middle-aged men who were brought up in the westernized dietary environment of modern Japan. METHODS: Thirty-three men, 30-49 years of age, attended a nutrition education class to learn food items and recommended volumes comprising the Japan Diet (more fish, soybeans and soy products, vegetables, seaweed, mushrooms and unrefined cereals, and less animal fat, meat and poultry with fat, sweets, desserts and snacks, and alcoholic drinks), and were encouraged to consume the Japan Diet for 6 weeks. Anthropometric and biochemical parameters were measured and 3-day weighted dietary records were kept before and at completion of the intervention. RESULTS: Ninety-one percent of participants showed improvements in more than one cardiovascular risk factor after 6 weeks. Body weight, serum low density lipoprotein (LDL) cholesterol, malondialdehyde modified (MDA)-LDL and triglyceride concentrations decreased significantly, while high density lipoprotein cholesterol was unchanged. Fish, soy, and sum of seaweed, mushrooms and konjak intakes doubled, and green and yellow vegetable intakes also increased as compared to baseline. Meanwhile, intakes of refined cereals, meat and poultry, sweets, desserts and snacks, and margarine and shortening decreased. Total energy, lipid, and saturated and monounsaturated fatty acid intakes decreased, while n-3 polyunsaturated fatty acid, dietary fiber, beta-carotene, vitamins D and K, potassium, and magnesium increased, with no change in sodium intake. CONCLUSIONS: The Japan Diet is suggested to improve atherosclerotic cardiovascular disease risk factors in middle-aged Japanese men.The clinical trial registration number: UMIN000020639.

Random presentation enables subjects to adapt to two opposing forces on the hand.

Studies have shown that humans cannot simultaneously learn opposing force fields or opposing visuomotor rotations, even when provided with arbitrary contextual information, probably because of interference in their working memory. In contrast, we found that subjects can adapt to two opposing force fields when provided with contextual cues and can consolidate motor memories if random and frequent switching occurs. Because significant aftereffects were seen, this study suggests that multiple internal models can be acquired simultaneously during learning and predictively switched, depending only on contextual information.