This study examined how different types of mayonnaise mixed with potatoes of various shapes. The less stable, larger-particle mayonnaise separated easily, particularly when mixed with mashed potatoes. Stable, fine-particle mayonnaise prevented oil separation, even with mashed potatoes. Most early Japanese potato salad recipes used cut potatoes, likely because the mayonnaise was less stable before 1955. Our findings suggest that improved emulsification technology has enabled modern recipes to use mashed potatoes rather than cut potatoes.

[Purpose] Seasonings have diverse characteristics depending on the country or region and are deeply rooted in local culinary traditions. Tamari soy sauce is produced mainly in the Tokai region, particularly in Aichi Prefecture, supporting the unique food culture represented by Nagoya-style cuisine. However, it remains relatively unknown nationwide, posing a challenge for broader consumption. By communicating the value of tamari soy sauce in cooking with scientific evidence, demand stimulation can be expected. This study aimed to analyze and quantify the cooking properties of tamari soy sauce as perceived by users. The study focused on (1) its ability to enhance gloss and sheen, (2) viscosity enhancing effects, and (3) cooking time reduction, comparing it with the widely used koikuchi soy sauce.

[Methods] The experiment involved cooking teriyaki of yellowtail and chicken using tamari or koikuchi soy sauce, followed by sensory evaluation using a paired comparison method to assess gloss and sheen. The viscosity of the teriyaki sauce was measured using a Rapid Visco Analyzer. Additionally, clam shigure-ni and simmered daikon were prepared with either tamari or koikuchi soy sauce, and changes in free amino acid and sodium content due to heating time were examined.

[Results] The gloss and sheen of the teriyaki were significantly stronger when using tamari soy sauce compared to koikuchi soy sauce. This was due to two factors: the brightness of the teriyaki sauce made with tamari soy sauce was lower than that made with koikuchi soy sauce, and its viscosity was 1.3 to 1.5 times higher, which increased the amount of sauce adhering to the surface of the food. Additionally, higher viscosity was expected to make flavors adhere more easily. Furthermore, for both clams and daikon, using tamari soy sauce resulted in the same free amino acid concentration in approximately half the heating time compared to koikuchi soy sauce, allowing for about 30% sodium reduction. Sensory evaluation revealed that clam shigure-ni was significantly softer and more palatable when cooked with tamari soy sauce.

[Purpose] Previous studies have shown that sake lees are rich in ingredients derived from raw materials and their metabolites, which are by-products of the sake brewing process, a traditional Japanese technique. Additionally, studies have indicated that sake lees possess health benefits. However, the disposal of sake lees has recently become a challenge due to their limited applications and shelf life, as well as shifting food preference, particularly among the younger generation. Hence, this study focused on mature lees, which can be stored for a long time and have a unique flavor, and the microorganisms in them. The study also reported changes in nutrients and functional ingredients produced by aminocarbonyl reactions and microbial activities during storage. This study further explores cooking methods that utilize the unique ingredients and flavors of sake lees to expand their applications.

[Method] The samples were provided by a sake brewer in Hyogo Prefecture who brews using the traditional natural fermentation inherited from the Edo period (1603-1868). They were obtained during the sake brewing process using Yamada Nishiki rice from Hyogo. Previously, we reported on sake lees stored for 50, 100, and 200 days at room temperature, along with a separate sample of 3-year lees. We compared six types of sake lees including 1000-day lees with an extended storage period. In addition, we isolated and cultured bacteria in the sake lees and 200-day lees, and identified the species by the 16SrRNA gene analysis. Based on these results, we analyzed the cooked products made from sake lees and stored lees.

[Results and Discussion] The genetic analysis identified two bacterial species in both sake lees and 200-day lees. One is B. subtilis which includes natto bacteria, and the other is P. megaterium, commonly found in fermented foods and wine. The latter produces vitamin B12, which explains its abundance in sake lees, despite its low concentration in raw rice. To promote broader use of sake lees, we explored cooking methods such as heating or pairing them with cheese or citrus fruits to balance their characteristic flavor and improve their appeal.

[Introduction] Antimicrobial-resistant bacteria are ineffective or difficult to respond to antibiotics. Contamination of food products as well as medical facilities and the livestock and fisheries industries with antimicrobial-resistant bacteria has been reported. Therefore, One-health action is needed on a global scale to prevent the spread. In particular, vegetables and seafood are often eaten raw, which may lead to the creation of new antimicrobial-resistant bacteria in the human body. To clarify the risk of this transmission, this study investigated the distribution of antimicrobial-resistant Gram-negative bacteria including Vibrio spp. in retail seafood, and attempted to detect antimicrobial resistance genes and identify the bacterial species.

[Materials and Methods] Antimicrobial resistance genes were detected using each strain isolated from 50 retail seafood samples reported previously (53 strains isolated by direct smear, 229 strains isolated by enrichment selection). Octaplex PCR was used to detect antibiotic resistance genes in addition to last year's method. In addition, 16S rRNA gene sequencing was used to identify the bacterial species of the resistant strains.

[Results and Discussion] Among the direct smear isolates, CTX-M type extended-spectrum β-lactamase (ESBL) gene (bla_CTX-M) was detected in 7 strains (13.2%) and class 1 integron (intI1) was detected in 1 strain (1.9%). Among the selected isolates after enrichment culture, bla_CTX-M was detected in 6 strains (2.6%) and intⅠ1 was detected in 9 strains (3.9%). Octaplex PCR results showed that the AmpC β-lactamase gene was detected in 2 strains(3.8%) from direct smear isolates and in 31 strains (13.5%) from selective isolates. The species were mostly Enterobacterales, including Citrobacter spp. and other Enterobacteriaceae, and Morganellaceae, including Providencia spp. and Serratia spp. Other species identified were Aeromonas spp., Pseudomonas spp. and Acinetobacter spp.

[Objective]Texture is a characteristic that determines the deliciousness of bakery products, and it is important to objectively understand the changes that occur after baking and to conduct research to control these changes. In this study, sensory evaluation of the differences in texture between freshly baked and stored rolls and French bread was conducted based on the results of a questionnaire survey, with the aim of clarifying the relationship between texture and overall evaluation of bread under different storage conditions.

[Methods]In the questionnaire survey, 55 texture evaluation terms extracted from previous studies1) were presented, and participants were asked to select the appropriate term (n=219, female university students in their 20s) by imagining the texture of bread rolls, French bread, and bread based on their daily eating experiences. The frequencies of the selected terms were tabulated, and the similarity of the terms was examined by cluster analysis. Sensory evaluation (n=17-20) was conducted using a linear scale from -4 to +4. Samples for sensory evaluation were control samples without storage, and control samples stored at different temperatures (4°C, 25°C) and times (24h, 48h, 72h). The French bread was also re-baked.

[Results] Based on the results of the questionnaire data, 55 texture terms were classified into 7 clusters. Based on the classification, four terms were selected as evaluation terms for both items. Sensory evaluation results showed that both items showed an increase in “crispiness” and a decrease in “softness” with storage, and the change was greater at 25°C than at 4°C. The French bread showed an increase in ‘crispiness’ and a decrease in “softness” with storage at 25°C than at 4°C. The scores of French bread improved after re-baking. Although refrigeration is generally considered undesirable for starch aging, the results of this study showed the opposite trend. These results revealed that the texture characteristics of the two bakery products were related to the overall evaluation after baking, and suggested that the susceptibility to the storage conditions varied depending on the type of bread.

In recent decades, the commercial use of cooked rice, for ready-made meals, has been steadily increasing in Japan. In Miyagi Prefecture, approximately half of the rice produced is supplied for the market, including restaurants, food processing, and other commercial applications. To identify rice varieties suitable for commercial use, we established novel evaluation indices: weight stability while molding the rice and tolerance to breakage when fluffing after cooking. Correlations between these new indices and conventional eating quality parameters were analyzed to reveal their relationship. There was a significant correlation between weight stability and physical properties of cooked rice surface. Also, tolerance to breakage showed a correlation between physical properties of whole cooked rice, amylose contents and Mido-value.

[Objective] This study introduces “Opekta,” a pectin product sold by Opekta Trading Company, which was operated by Otto Frank, the father of Anne Frank, author of “The Diary of a Young Girl.”

[Methods] Using the book “Kook- en huishoudboek” (Cooking and Home Economics) published in 1937 (Showa 12), the content and related matters were investigated in the section titled “HET MAKEN VAN JAM MET GEBRUIK VAN ‘OPEKTA’” (How to Make Jam Using ‘Opekta’) on pages 90–98. The author, Wilma Münch, was a teacher of agriculture and home economics. The publisher was Münch Bookstore, the place of publication was Utrecht, and the edition was the third revised edition of the first one published in 1931.

[Results] The Amsterdam Opekta Company was established by Otto Frank in 1933 (Showa 8) as a branch of the Swiss Basel headquarters. The company primarily manufactured and sold gelling agents and pectin used in jam and jelly production. Otto also operated the Pectacon Company (spice sales for meat products, 1938–). The “hiding place” where Anne and others hid during the war was located behind the office building of these companies. Opekta was pectin extracted from apples, with its natural origin emphasized. The product was available in liquid and dried forms. Compared to traditional jam-making methods, the advantages of using Opekta were as follows: shorter heating times, preservation of aromatic components, and the ability to make jam from fruits that did not easily thicken. The fruits listed as jam ingredients included strawberries, apples, blackberries, blueberries, raspberries, currants, cherries, plums, apricots, peaches, rhubarb, tomatoes, and oranges.

[Purpose] Curcumin is a yellow polyphenol compound found in turmeric (turmeric (English: turmeric), scientific name: Curcuma longa). It is classified as a curcuminoid. It is used as a colouring agent in spices and foodstuffs and is designated as an existing additive (colouring agent) in Japan as turmeric pigment. Curcumin's physiological effects are known to include anti-tumour, antioxidant, anti-amyloid and anti-inflammatory effects. This study reports on the development of new recipes using turmeric for young people, including children who are not fond of spicy food.[Methods] Six recipes were prepared. The recipes were examined in terms of taste, ingredients, cooking utensils and methods, nutritional value, cost, time and effort, etc. [Results] The results suggest that the recipes presented here can be prepared at home, etc. On the other hand, many of the menu items are only freshly prepared when they are ready to eat. It is necessary to develop recipes for lunchboxes and other dishes that can be eaten after a certain amount of time. The recipes presented here are mainly dishes that use turmeric as a seasoning. The challenge for the future is to develop recipes in which turmeric plays a leading role in the true sense of the word.

[Purpose] Dietitians are expected to possess precise knife handling and culinary skills. However, many students aiming to become dietitians lack sufficient experience or accuracy in their knife techniques. To address this, we explored an instructional method that utilizes data recorded with motion sensors to objectively assess and improve students’ knife handling skills.

[Method] First-year students at a junior college were asked to record their movements while slicing cucumbers using a kitchen knife equipped with a sensor on the handle. Based on the results of data analysis, individual students were made aware of areas for improvement by referring to the characteristics of their individual operation data, the operation data of skilled workers, and interview content. Step-by-step guidance was then provided. Measurements were taken again in the fifth week, and the changes in data analysis were compared with those before the guidance.

[Results] Before coaching, students tended to show larger movements around the roll axis compared to the pitch axis, indicating instability in their cutting motion. After instruction, the pitch-to-roll ratio increased in most students, reflecting a shift toward more controlled, forward-directed cutting. Notably, all 12 participants exhibited the emergence of pitch-dominant motion at the rear end of the knife handle, leading to reduced blade wobble and a cutting motion closer to that of experienced practitioners.

[Objective]

It is expected that juiciness has a significant effect on the taste and palatability of fruits and vegetables, although the details of this effect are unknown. In this study, two samples with different physical properties created from the same amount and composition of fruit juice and coagulant were compared by sensory evaluation to clarify the effect of juiciness on taste and palatability.

[Materials and Methods]

Strawberry, mandarin, and melon fruit juices hardened by adding agar (gel samples) and samples soaked with fruit juice on tasteless, odorless, spongey agar that was freeze-dried after hardening water (spongey samples) were prepared. The gel and spongy samples were instrumentally analyzed for moisture content, juice release rate, and hardness. In addition, sensory evaluation was performed to compare sweetness, sourness, and juiciness intensity and palatability.

[Results and Discussion]

The moisture content of the prepared samples was lower in the spongy samples compared to the gel samples only for strawberries. The reason for this was considered to be the low penetration of fruit juice into the spongy agar resulting in a higher ratio of coagulant in the sample. There was no difference in moisture content between the mandarin and melon samples. In all samples, the spongy samples were softer and had a higher juice release rate. The results of the sensory evaluation showed that the spongy samples were significantly higher in juiciness than the gel samples for all of the strawberry, mandarin, and melon samples. However, the mandarin and melon samples showed no difference in moisture content, while the strawberry sample had a lower moisture content. These results indicate that higher moisture content does not necessarily increase juiciness. In terms of taste, the sweetness of the spongy sample was significantly stronger in all samples, while there was no difference in the sourness of the samples. Regarding palatability, the spongy sample with stronger juiciness was significantly preferable for mandarins, whereas there was no difference for strawberries and melons. These results indicate that the higher juiciness does not necessarily increase palatability.

Recent studies on astringency and fat-substitute will be reported. Frictional coefficient of model wines (tartaric acid, ethanol, water) and artificial saliva (porcine gastric mucin, KCl, NaCl etc) was measured using steel on 3 PDMS pins method, and the Stribeck curves were obtained. Together with DLS, AFM and QCM-D, results showed that the larger the size of the complexes with the model saliva, and the higher the thickness, viscoelasticity, and roughness of the adsorption film formed with increasing concentration of tannin, which resulted in the increase of friction coefficient in the boundary lubrication regime. It was found that the maximum value of the friction coefficient in the boundary regime has the best positive correlation with the astringency perception intensity of the model wine. To reduce or replace trans fatty acid using plant-based food materials, oleogels were prepared by adding a small amount of water to soy fibre particles (SFP) (SFPs are agricultural residues which can contribute to sustainability) -soy oil dispersion. It was shown that the SFP based networks were dominated by the capillary force which was originated from the second fluid. The rheological properties and yield stress of the oleogels could be modulated by particle size and particle content of SFP in oil phase, as well as the second fluid content in the system. Bread made with butter or SFP-oleogels showed similar appearance, inner structure, and color, exhibiting their potential to displace the butter in bread.