As the physical properties and functionality of dipeptides differ from those of amino acids, they have attracted attention in metabolomics; however, their functions in vivo have not been clarified in detail. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and its major cause is chronic hepatitis. This study was conducted to explore tumor-specific dipeptide characteristics by performing comprehensive dipeptide analysis in the tumor and surrounding nontumor tissue of patients with HCC. Dipeptides were analyzed by liquid chromatography tandem mass spectrometry and capillary electrophoresis tandem mass spectrometry. Principal component analysis using 236 detected dipeptides showed differences in the dipeptide profiles between nontumor and tumor tissues; however, no clear difference was observed in etiological comparison. In addition, the N- and C-terminal amino acid compositions of the detected dipeptides significantly differed, suggesting the substrate specificity of enzyme proteins, such as peptidase. Furthermore, hepatitis-derived HCC may show a characteristic dipeptide profile even before tumor formation. These results provide insight into HCC pathogenesis and may help identify novel biomarkers for diagnosis.

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In general, vegetables are abundantly consumed in a calorie-restricted diet to achieve sufficient satiety through fresh food or various cooking methods. In this study, we examined the effects of different cooking methods on appetite and specific perceptions of the food after consumption; eating approaches were also analyzed by meal duration. A total of 153 individuals aged 20-59 years were assigned to 2 groups: raw vegetable or boiled vegetable meals, including packed meals that were served as test meals with the same energy and vegetable amount. Subjective levels of sensory properties and meal duration were assessed over time using visual analog scales, including questionnaires. Results showed that meal duration was significantly longer for raw vegetable meals than boiled vegetable meals, and there were significantly stronger correlations between meal duration and fullness. A higher degree of fullness was provided by a raw vegetable meal than a boiled vegetable meal, especially in men. However, an excess of raw vegetables led to overall insufficient satisfaction. Taken together, these findings suggest that cooking methods should be altered for different situations with an adequate amount of vegetables, and the meal duration should be recommended to be given as much attention as cooking methods.

: Reducing dietary calorie density (CD) is useful in body weight management. This study investigates the association between dietary habits and preferences for different CDs. We conducted a randomized crossover study of 232 healthy subjects who consumed packed lunch boxes containing a control, high-meat and low-rice, low-vegetable, medium-fat and low-vegetable, high -fat, and high -fat and low-vegetable meals over six sessions. The subjective levels of sensory properties were assessed over time using a visual analog scale and the area under the curve. Subjects were assessed for dietary habits using a brief-type self-administered diet history questionnaire (BDHQ) and were divided into two groups based on a daily fat energy ratio 25% % (high fat [HF], n = 116) and 25% % (normal, n=116) that was matched for age, body mass index, and sex ratio. Our findings indicate that the desire for sweetness was higher in the HF group than in the normal group, regardless of the meals consumed. Particularly, among the 500-kcal low-CD meals, a high-protein meal provided greater fullness and satisfaction and lower prospective consumption in the HF group than in the normal group. Therefore, our study demonstrates that postprandial appetite sensation is associated with dietary habits of fat intake.