The objective of this study was to evaluate the appearance, texture, palatability, and nutritional content of apple chips fried either under vacuum or at normal pressure. Furthermore, we also evaluated the effects of heating temperature (75°C, 85°C, 95°C) on the properties of apple chips fried under vacuum.

Vacuum-fried apple chips (VFACs) were brighter than normal-pressure-fried apple chips (NFACs). A palatability evaluation revealed that the VFACs were lighter in color, smelled better, less greasy, had a more suitable texture, and tasted better compared to NFACs. VFACs had a significantly higher vitamin C content and lower amounts of lipid peroxidation products compared to NFACs, indicating that oxidation was suppressed during the processing of VFACs.

A palatability evaluation revealed that VFACs that were heated at 75°C were lighter in color, less greasy, and tasted better compared to VFACs that were heated at 95°C. VFACs that were heated at 75°C had a significantly higher vitamin C content compared to VFACs that were heated at 95°C, indicating that the aminocarbonyl reaction was inhibited and oxidation was suppressed during the processing of VFACs at 75°C.

Higashi is a generic term that refers to dry Japanese confectionery, and uchimono, such as rakugan and wasanbon, is one of the representatives of higashi. Uchimono is made and moulded from powdery ingredients (such as sugar and flour), and melts quickly in the mouth with a flavourful sweetness derived from wasanbonto (refined sugar made in Japan from sugar cane).

The present study examined the methods of making uchimono. Through a literature review, various issues involved in the preparation of uchimono were investigated. Preparation methods were classified according to the four main ingredients (such as sugar, rice flour, other flour and salt). The effects of different kinds of sugar on the colour and physical properties of uchimono "Wasanbon", made using only sugar, were examined. Uchimono made with wasanbonto had more hardness and lesser brightness than that made with refined white sugar. The method of adding nekimizu (water containing starch syrup) affected the hardness of uchimono. It was easier to make uchimono using nekimizu than with water without starch syrup.

Using a questionnaire, we conducted a survey to collect data on the methods used for cooking rice porridge, which is usually the first solid food given to infants in Japan. The subjects belonged to two main groups: the parents of children born between March and May 2018, and the parents of university students aged 19.7±1.1 years. The results of the survey showed that at present rice porridge is mainly being cooked using a microwave oven, rice cooker, or hand blender, instead of using a traditional pot. However, 18.9% of present-day parents checked "preparing the rice porridge in a pot using cooked rice" as the primary method used by them, suggesting that the traditional method is still in use. Freezing for storage has become more common and the corresponding storage period has become longer compared to 20 years ago. These findings could be attributed to the rise of freezing at home. This also suggests a need for dissemination of information on appropriate home freezing methods. Furthermore, in terms of storage containers, the proportion of parents who use dedicated containers for storing baby food increased compared to 20 years ago.

Various studies have reported the importance of acetic acid in preventing lifestyle-related diseases. However, the actual amount of acetic acid that can be used in commercial products and menus introduced through vinegar-based cooking has not been investigated. Analysis of acetic acid content revealed that it was difficult to consume 750 mg acetic acid per day, which appears to be effective in preventing lifestyle-related diseases. Therefore, for the purpose of consuming 1,000 mg of acetic acid per serving, a portion of chicken breast was cooked in vinegar containing bitter ingredients in addition to sweet, salty, and umami ingredients through a new vacuum cooking method using a sealed bag, following which the acetic acid content was determined. In the steam mode (100% steam at 85°C in a steam convection oven), when the chicken breast core temperature reaches 75°C, then continue to heat for 5 minutes and soak for 2 days, the acetic acid content was found to be ≧1,000 mg on an average per 100 g of cooked chicken breast.

We investigated the current state of rice-cooking practical lessons taught by home economics teachers in 306 public elementary schools in the Kinki district in 2013 and 234 schools in the Kanto district in 2014 by administering a questionnaire. The results revealed that in most schools, fifth-year students participated in these lessons. More than 90% of the classes used cooking pots of which 85% were made of glass. The practical lessons were based on the instructions given in textbooks. Many teachers experienced difficulties in the instructions related to the control of heat intensity, countermeasures against burning, and instructions to control heating time. The teachers understood that their students were satisfied when they cooked the rice by themselves and that the students were interested in the changes the rice underwent during cooking. The teachers were of the view that rice-cooking practical lessons were important. It is recommended that the three problems noted should be addressed in the future.