Milk proteins play an essential role in yogurt manufacture, by adsorbing onto the fat globule interface. This study aims to clarify the impacts of milk fat globules on the physicochemical properties of stirred yogurt, by modifying the particle size distribution of fat globules in reconstituted milk. The results show that high-pressure homogenization increased the association between milk proteins and milk fat globules. The zeta potential and protein surface hydrophobicity of reconstituted milk samples increased. Stirred yogurt prepared with reconstituted milk homogenized at high pressure (≥ 20 MPa) exhibited a fine mesoscopic structure with higher water holding capacity and apparent viscosity. Based on transmission electron microscopy and atomic force microscopy, the milk fat globules tended to form effective connections with casein micelles, giving the yogurt a finer network structure and higher viscosity. These findings reveal that controlling milk fat globule size can effectively improve stirred yogurt quality.

Tons of eggshell waste contribute to the reduction in landfill capacity worldwide. This situation necessitates the development of diverse applications to expand their effective use. To develop new applications for eggshell, this study investigated the effects of eggshell powder on the flow properties of potato starch. Changes in the flow properties were evaluated by adding fine eggshell powder to potato starch at a concentration of 0.5–2.0 % (w/w). The angle of repose of potato starch without eggshell powder was 63 °. However, it decreased to 38 ° following the addition of eggshell powder at 2.0 % (w/w). In addition, eggshell powder positively affected the dynamic flow, bulk, and shear properties, indicating improvement in the flow properties of potato starch. Furthermore, eggshell powder changed the pasting properties of potato starch, with low and stable viscosities observed during heating. The findings demonstrate that the addition of eggshell powder improves the flow properties of potato starch. This could expand the applicability of this powder as an additive in food production.

β-Conglycinin (β-CG), a major soy protein, has been associated with the reduction of body fat and triglycerides in the blood. Quantitation of the α, α′, and β subunits in β-CG is desirable to establish the functional properties of β-CG in soybean. Therefore, in this study, we used the Jess System, a capillary electrophoresis-based immunoassay system, for quantifying β-CG in soybean foods. The validity of this method was confirmed using soybeans and processed soy milk. The within-laboratory reproducibility of the total β-CG amount was < 15 %, and its trueness was > 80 %. The β-CG content in the commercially available soybeans, Kori-tofu, soy milk, soy yogurt, Okara powder, and soy meat was determined to be 40.3–148.5, 65.2–97.2, 6.1–7.8, 3.5, 18.0, and 57.5 mg/g, respectively. For the first time in the literature, this method enables the quantitation of individual subunits of β-CG, despite the large variation in the amount of each subunit.

The behavior of a raw carrot bolus through a vertical pipe was investigated with a laser detector. To investigate the effect of cohesiveness, samples were pre-processed in various stages, as follows: no compression, 50 % and 80 % compression, and blending with xanthan gum. First, the transit time of the bolus was measured from the time series signal of the voltage drop corresponding to the density of the food fragments. The results showed that the transit time was shorter for the bolus with greater assumed cohesiveness. Next, we analyzed the structure of the bolus flow by obtaining the power spectrum of the time series signal, which exhibited a power-law relationship of the form P(f) ~ f^−α. The value of the exponent α, reflecting the structure of the bolus flow, was also shown to be correlated with the assumed cohesiveness. Therefore, we propose that α can be used as an index to evaluate bolus cohesiveness under shear conditions.

Three tsukudani seasoning liquid models of soy sauce and amino acid seasoning liquid mixed with rare sugar syrup (RSS, main rare sugars: d-allulose, d-sorbose, d-tagatose, d-allose), glucose-fructose liquid sugar (GF), and white sugar (WS) were heated in a headspace sampler to create a delicious aroma. The aroma components generated were then analyzed using HS-GC/MS. As a result of the Maillard reaction, brown color intensity measured at absorbance 420 nm in the RSS liquid was significantly higher than in the GF and WS liquids. Principal component analysis of the quantitative data of the aroma compounds revealed 1.1–4.5 times more furans such as furfural, furfuryl alcohol, 2,5-diethyl tetrahydrofuran, and 3-phenylfuran were released from RSS than from GF and WS, which contributed to the characteristic aroma components of the tsukudani seasoning liquid. These results suggest that the four main rare sugars in the RSS are involved in the aroma formation.

Pineapple is an important representative fruit of Okinawa Prefecture, Japan. The fruits of the five new breeding lines (“Okinawa No. 22,” “Okinawa No. 25,” “Okinawa No. 26,” “Okinawa No. 27,” and “Okinawa No. 28”) were evaluated for physicochemical traits, total carotenoids, volatile components, and orthonasal aroma profiles. The fruits had comparable weight, total soluble solids, and titratable acidity but displayed different color space b* values (yellow index). This yellow indicator was positively associated with total carotenoid content, with the “Okinawa No. 26” line having the most (8.74 mg/kg). The amount and composition of volatile components and, consequently, aroma-active compounds varied between fruits. The “Okinawa No. 28” line contained the most active-aroma compound methyl 2-methylbutanoate (odor activity value = 297.78). Except for “Okinawa No. 25,” the lines were associated with pleasant orthonasal aromas, such as fruity, sweet, coconut-like, and peach-like, indicating their potential use in fresh or processed foods.

The astringency of persimmon fruits is a significant factor for consumers and the nutritional industry. To date, astringents, such as polyphenols, specifically persimmon condensed tannins, have been assessed using polyphenol quantification assays, such as the Folin–Ciocalteu method, based on their reducing power. However, these methods are influenced by the presence of other reducing substances. In this study, we developed a cost-effective liposome turbidity analysis using a portable visible spectrophotometer based on the interaction between liposomes and astringents. Authentic astringents, such as catechins and theaflavin-3-O-gallate, were analyzed, and their half-maximal effective concentrations (EC₅₀) were calculated. These results indicated that the affinity to the membrane was similar to that of astringency, as determined by sensory analysis. Additionally, the EC₅₀ values of partially purified tannins from non-astringent and astringent persimmons were calculated. In conclusion, we determined the application methods to assess astringent persimmon fruits with and without the removal of astringency.

In this study, the dnaK gene-deletion mutant strain of Escherichia coli BW25113 showed a higher susceptibility than the wild-type strain of E. coli BW25113 to phage S127BCL3. Flavonoids, myricetin and quercetin which had been reported to suppress the role of DnaK were tested to examine their effects on the phage susceptibility of E. coli BW25113. A 6-h pretreatment with 500 µmol/L myricetin or quercetin increased the phage susceptibility of E. coli BW25113. A similar result was observed in E. coli O157:H7. Real-time quantitative polymerase chain reaction (qPCR) was conducted to investigate the effects of flavonoids on the transcription of chaperone genes (dnaK, dnaJ, groEL, and grpE) in E. coli. Pretreatment of wild-type E. coli BW25113 with flavonoids decreased the transcription of chaperone genes. This is the first report demonstrating the enhancement of the phage susceptibility of both E. coli BW25113 and E. coli O157:H7 by flavonoids. The results of this study on the combined effects of flavonoids involved in foods and phages on E. coli provide scientific bases for development of a novel biocontrol method of foodborne bacteria.

It is known that using high-purity water such as distilled water or Milli-Q water for extracting coffee changes the taste. Further, since the purity of ice manufactured by an ice-making system is also high, we investigated whether the taste would change when coffee was extracted using water produced from melted ice. Sensory evaluation showed that coffee brewed with the melted-ice water had an improved clean taste. Content analysis of chlorogenic acid, caffeine, cations and anions showed that the coffee brewed with melted-ice water had a low sodium content. When sodium was added as an organic-acid salt to the coffee extraction water, taste sensor analysis revealed that the salty taste increased and the clean taste of coffee decreased. Therefore, this suggests that the clean taste of coffee depends on the sodium content of its extraction water.

Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry was utilized to analyze the volatile compounds in cooked barley. A total of 56 compounds were identified, including 18 aldehydes, 13 ketones, 6 alcohols, 6 furans, 5 acids, 2 furfurals, and 6 others. The grains of waxy and nonwaxy barley were pearled and stored at either 5 °C or 40 °C for 5 months prior to cooking. The waxy genotypes exhibited higher levels of key odorants in cooked barley, such as hexanal, 2-octenal, 2,4-nonadienal (E, E), and 2,4-decadienal (E, E), compared to the nonwaxy genotypes. Elevated storage temperatures (40 °C) led to an increase in 42 volatile compounds, particularly 2-butyl-2-octenal in cooked barley. Principal component analysis revealed distinguishable profiles of volatile compounds among the nonwaxy 40 °C storage group, the waxy hull-less 40 °C storage group, the waxy hulled 40 °C storage group, and the 5 °C storage group.

The isoflavone aglycone (IA) contents of commercial fermented soybean products in Korea, such as cheonggukjang and doenjang, and the IA-producing ability of the Bacillus subtilis strains isolated from the products were examined. Among three commercial products, product C (doenjang), which is produced using a long fermentation method, showed the highest conversion rate of isoflavone glucosides to aglycones. Of all eight B. subtilis strains isolated from the products, four strains had the same or higher level of IA production than B. subtilis (natto), with the C-3 strain showing the highest level. Hence, the difference in the conversion rate among the products might be attributed not only to fermentation time during the manufacturing process, but also the IA-producing ability of the B. subtilis strains. Moreover, the C-3 strain produced IA during the early stage of culture with soybean liquid medium, and the IA-producing ability of the C-3 strain in the fermentation with soybean solid medium was higher than that of B. subtilis (natto). Thus, the rapid IA production by the B. subtilis C-3 strain might contribute to the high IA content of product C.

Despite considerable research and developments in the color properties of plant-based meat analog (PBMA) products, their color changes during the grilling process are one of the main unsolved challenges. Recently, it was reported that a novel browning system for PBMA products containing a red pigment (betanidin) and a multicopper oxidase (laccase; LC) can simulate the color changes (red to brown) of animal meat. However, the reaction products in PBMA using this system have not been analyzed in detail. Thus, this study aimed to clarify the reaction products of betanidin oxidized via LC-catalyzed reaction. It was found that LC-catalyzed oxidation in the PBMA patties degraded betanidin to betalamic acid and cyclodopa, subsequently polymerizing these degradation products to produce unknown brown polymers. These findings provide suggestions for the browning mechanism of PBMA patties containing betanidin via LC-catalyzed oxidation.

From traditional Gifu ayu-narezushi, Leuconostoc, Latilactobacillus, and Enterococcus were isolated as dominant genera. Isolated strains of Leuconostoc mesenteroides showed high growth inhibition activity against Staphylococcus aureus and Escherichia coli. The isolated strain, Enterococcus lactis EC52, could produce γ-aminobutyric acid (GABA). These results indicated that Enterococcus lactis and Leuconostoc mesenteroides were lactic acid bacteria, which have GABA-producing and antimicrobial activities, respectively, in traditional Gifu ayu-narezushi.

Luteolin, widely present in plants, has various physiological functions. Here, we aimed to investigate whether luteolin affects lifespan and oxidative stress tolerance using Caenorhabditis elegans. Luteolin had no effect on the lifespan of wild-type N2 worms under normal conditions. In contrast, luteolin prolonged the lifespan of N2 worms under oxidative stress, suggesting that luteolin enhances oxidative stress tolerance. Luteolin upregulated the expression of gst-4, sod-1, sod-2, sod-3, and ctl-3 in N2 worms under oxidative stress conditions. The expression of these genes was regulated by DAF-16. Prolongation of lifespan and induction of gene expression by luteolin under oxidative stress conditions were not seen in daf-16 (mu86) mutants. These results suggest that the enhancement of oxidative stress tolerance by luteolin was mediated by the daf-16 pathway in C. elegans.

We investigated the antiallergic effects of 80 % methanol (80M) extracts obtained from Ecklonia cava subsp. stolonifera, harvested along the coast of Nishinoshima Town, Oki Islands, Shimane Prefecture, Japan, at different stages of algal powder manufacturing (involving heating operations). The radical-scavenging activity of the extracts increased during the manufacturing process. The extracts could mitigate allergic inflammation in mice and degranulation in rat basophilic leukemia-2H3 cells. The contents of typical algal polyphenols, such as phlorotannins (eckol, 6,6′-bieckol, 8,8′-bieckol, dieckol, and phlorofucofuroeckol-A), in the 80M extracts were analyzed via high-performance liquid chromatography and liquid chromatography-mass spectrometry, which revealed that eckol and dieckol were more abundant than the other three phlorotannins throughout the manufacturing process, while an increasing trend in the contents of all five phlorotannins was observed in later stages of the manufacturing process. Furthermore, measurement of the total polyphenol content revealed the probability of polyphenol polymerization during manufacture.