In this study, we compared the physicochemical properties and sensory attributes of low temperature pasteurized (LTLT) milk and ultra-high temperature treated (UHT) milk, both of which were produced using the same raw milk. The consumer tests indicated that the odor, sweetness, thickness, and after-taste were weaker in the LTLT milk compared to that in the UHT milk (p＜0.01) and that the LTLT milk was more refreshing than the UHT milk (p＜0.01). Although the taste of UHT milk was more familiar than that of the LTLT milk (p＜0.05), there was no difference in palatability of the two milks. The odor of the LTLT milk resembled that of raw milk when the odor was analyzed at 40°C, 50°C, and 60°C by using an odor sensor. However, the odor of UHT milk was different from that of both the LTLT milk and the raw milk. The viscosity of the LTLT milk was lower than that of the UHT milk (p＜0.05). The hardness of custard puddings prepared using LTLT milk was lesser than that of custard puddings prepared using UHT milk (p＜0.01). In addition, the sensory evaluation with the expert panel indicated that the custard pudding prepared using LTLT milk was softer and had a better melting feeling in the mouth compared with that prepared using UHT milk (p＜0.01).
The purpose of this study was to propose novel tasks that may increase both subjective and objective stress responses.In this study, we assigned the experiment collaborators a 30-minute calculation load similar in format to the Uchida–Kraepelin psychodiagnostic test. In Experiment 1 (measurement of objective stress response), we measured salivary α-amylase activity (sAMY) at one point before the calculation load and at eight points after the calculation load. In Experiment 2 (measurement of subjective stress response), we asked the subjects to rate their degree of stress before and after the calculation load, using a 5-point evaluation method.The results showed that the sAMY value recorded immediately after the loading was significantly higher than that before the loading.The degree of stress reported using the 5-point evaluation method also varied significantly between before and after the loading. We concluded that the calculation tasks used in the present study significantly increased subjective and objective stress responses.
We investigated the feasibility of using an audience response system (ARS) to measure and immediately display the effect of lectures on food safety, related to pesticide residue and radiological substances, on an audience’s responses. Students were asked closed questions about typical misperceptions related to food safety, both during and after their lectures. In Experiment 1, 105 students answered six true-or-false questions, including those about pesticide residue and bovine spongiform encephalopathy (BSE). In Experiment 2, 101 students also answered six true-or-false questions, but one question about BSE was replaced by a question about radioactive material. All students responded using an ARS, and the overall true/false rate for each question was displayed to them immediately after each response. The results reveal that the proportion of questions answered correctly was higher after the lecture than during the lecture in both experiments. In addition, the number of participants who answered each question correctly after the lecture was significantly larger than that during the lecture for four of the six questions in both experiments. This study indicates that the effect of a food safety lecture on students’ understanding is easily measurable using an audience response system.
In this study, the correlation between sensory values and rupture properties of pork was examined. Rupture properties were significantly correlated with fibrous feeling, fiber coarseness, juiciness, overall judgment, and chemical properties. However, they were not correlated with tenderness and overall texture. Stress–strain curves were also examined; a linear shape indicates a constant stress–strain increase, while a curved shape indicates a gradual increase. Pork varieties yielding a curved shape were considered tender. Upon examination of the compression ratio, 20–30％ of the compression properties were well correlated with the sensory values. These results emphasized that initial tenderness in the first bite is important.