Effective food texture control technologies are needed to meet the increasing demand for nursing care and alternative food products. Detailed information, including that on the textures of different food parts, is necessary to develop such technologies. Therefore, we consider to examine the surface stress distribution in different food products. In this article, we describe our findings on the pressure distribution measurement conditions for burdock root and carrot. Thickness should be uniform in all samples as differences in thickness affect the stress distribution measurements. A microtome blade or similar tool with a sharp thin blade was used to cut the samples. It is possible to evaluate the stress distribution for each part even when the food thickness is 5 mm or less.Thickness was set to 2.5 mm to evaluate the stress distribution in the burdock root microstructures with different textures. It is suggested that comparison of stress distribution in samples with different cutting directions may provide important information on the three-dimensional structure of food.

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Although thermal sterilization reportedly alters the flavor of packed food, few studies have systematically examined this change. We have previously demonstrated that inosinic acid, which imparts umami in dried bonito extract (katsuo-dashi), decomposes to inosine and hypoxanthine; this decrease in the inosinic acid concentration contributes to flavor alteration (corroborated by sensory evaluation of a model liquid). Suppressing inosinic acid decomposition via sterilization may preserve katsuo-dashi's flavor. This study was focused on the role of pH in maintaining the flavor of katsuo-dashi after sterilization. Samples of katsuo-dashi and a model solution were enclosed in borosilicate glass ampoules and heated in an oil bath at 110, 120, and 130 ℃ to simulate thermal sterilization. After heating, the concentration of inosinic acid in the model solution, with pH 4.8–6.8 buffers, remained higher at pH 6.8 than at pH 4.8, indicating that adjusting pH could suppress inosinic acid decomposition. Therefore, a similar warming test was conducted by adjusting the pH of katsuodashi. However, in this case, the results varied, and the findings from the model solution were not reproduced. The complex components of katsuo-dashi influenced these results. Thus, pH adjustment was not effective for controlling inosinic acid decomposition and preserving flavor during thermal sterilization.

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The efficacy of fig tea derived from Ficus carica L. leaves in suppressing type I allergies is compromised when stored above ambient temperature, indicating temperature-dependent modifications in its bioactive constituents. This study aimed to identify these bioactive components by subjecting fig tea to various storage temperatures and subsequently quantifying their component compositions. The results revealed a significant decrease in disaccharide concentrations, specifically difructose anhydride, sucrose, and turanose, which correlated with the storage duration. These disaccharides demonstrated inhibitory effects in in vitro cellular assays, indicating their potential as bioactive agents in fig tea. In contrast, furocoumarin, another bioactive component, exhibited an increase in concentration proportional to the storage time. Notably, a reduction in the suppressive effect was not observed in fig cultivars devoid of furocoumarin in the storage experiments. These findings indicate the potential involvement of furocoumarin in the inhibition of the suppressive properties of fig tea under specific storage conditions.

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Tea infusions prepared from fig (Ficus carica L.) leaves have been shown to possess antiallergenic properties. The leaves of many fig cultivars contain furocoumarins, such as psoralen and bergapten, which, when ingested at high doses, can cause cytochrome P450 inhibition and phototoxicity. In the present study, we examined the furocoumarin contents and allergenic effects of fig leaf tea using storage tests. Sterilized or unsterilized tea samples were stored at 4℃, 30℃, and 55℃ for 12 weeks. The results showed that after unsterilized storage at 30℃, the furocoumarin contents increased by approximately two-fold in the first four weeks of storage and the allergy (degranulation)-inhibiting effects were suppressed. In the samples subjected to unsterilized storage at 4℃ and 55℃ and all samples subjected to sterilized storage, the furocoumarin contents did not change and the degranulation-inhibitory effects were maintained. The microorganisms that grow in unsterilized tea have been suggested to metabolize furocoumarin precursors (glycosides),leading to furocoumarin production. Hence, during fig leaf tea storage, measures to inhibit microbial growth, such as sterilization and low-temperature treatments, are recommended.

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Large amounts of unused rind are discarded during dried persimmon production. Comprehensive gene expression analysis has shown that the consumption of fat-soluble persimmon peel extract (PPE) improves insulin resistance in animal models of diabetes. However, no changes in blood glucose levels and other parameters have been reported to date. Therefore, the purpose of this study is to investigate the effect of PPE on the insulin resistance of male mice fed a highfat diet (60% fat) with 1.5% PPE for six weeks via glucose tolerance test. High-fat diet with PPE decreased the blood glucose levels after glucose loading better than the high-fat diet alone. However, no significant decrease in adipose tissue weight was observed, indicating that PPE alleviated high-fat dietinduced insulin resistance.

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Pentacyclic triterpenoids present in peels that are discharged in large quantities during fruit processing, exhibit many potentially exploitable physiological activities. Because the structure of each triterpenoid is similar, it is difficult to isolate and purify individual molecules. We thus developed a simple method for the isolation and purification of pentacyclic triterpenoids. Liquid chromatography (LC) with a C30 column was used to determine an optimal mobile phase. In primary purification, water, methanol, and acetonitrile were assessed as mobile phases for the simultaneous purification of multiple components. In secondary purification, water and acetonitrile were used as mobile phases to achieve higher purity of the primary purified product. Pentacyclic triterpenoids were purified from dried apple processing residues using an established method, and euscaphic, annurcoic, and pomolic acids were simultaneously purified in the primary purification. Secondary purification of an annurcoic acid fraction yielded a highly purified product with a purity of 95.7% (HPLC). Purification was repeated and 10.15 mg of annurcoic acid was obtained from 85.79 g of dried apple processing residue. This established method can easily yield multiple pure pentacyclic triterpenoids using preparative LC. This method is thus expected to simplify sample preparation and contribute to the effective utilization of processing residues as source materials.

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Persimmon fruit has a characteristic fatty acid (FA) composition with a high cis-vaccenic acid (cis-VA: C18:1, n-7) ratio; however, the effect of ingesting cis-VA is unknown. Therefore, to elucidate the effect of cis-VA upon ingestion, it was orally administered to normal (C57BL/6JJcl) and diabetic (KK-A^y/TaJcl) mice for 7 d. The FA composition of each tissue was analyzed to identify the tissues in which cis-VA acts, as well as those that may be affected by FA metabolism. cis-VA administration altered the FA composition of the pancreas in normal mice and the hearts of diabetic mice. Multiple FA ratios were altered, with five FA showing common changes between the heart and pancreas. This suggests that cis-VA ingestion may affect the pancreas and heart, and cause common changes in FA metabolism. Overall, cis-VA may have unique actions that differ from those of other monounsaturated FA.

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We investigated the effects of the inorganic elemental composition of liquid fertilizers on the growth and yield of rockwool cultivated ‘Masui Dauphine’ (synonym of ‘San Piero’), the major domestic fig variety. In a previous report (Takahashi et al. 2022), we showed that liquid fertilizer with higher phosphorus and lower potassium, magnesium and manganese contents, and higher concentration than control fertilizer, produced a higher fruiting node rate. Furthermore, the amount of phosphorus in the leaves after harvest was positively correlated with the fruiting node rate, whereas the amount of iron was negatively correlated. In this study, we investigated (1) the effect of altering the liquid fertilizer composition and concentration on the regeneration of bearing shoots (immediate effectiveness), and (2) the concentration dependence of the liquid fertilizer effects. The results of (1) confirmed that changes in the composition and concentration of liquid fertilizer were immediately reflected in fruiting node rates. The results of (2) showed that the fruiting node rate increased depending on the concentration of the liquid fertilizer. However, the upper limit and optimum concentration have not been clearly defined.

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The effect of different pruning methods on breba (the second) crop production of a San Pedro type ‘Dauphine’ fig was studied. The pruning methods compared were “heading”, in which the bearing shoots grown from autumn of the previous year to July of the current year were cut back shortly after harvest in July, and “thinning”, in which bearing shoots grown from spring of the previous year to July of the current year were cut off from the bifurcation point where the bearing shoots for next season were developing. Both pruning methods were conducted in summer immediately after harvesting breba fruit. Although there were more cases of fruit overwintering in the ‘heading’ method, the number of mature fruits did not differ between the two pruning methods because of the subsequent fruit drop to maturity. In addition, no differences in ripening date and fruit quality (skin colouring and sugar content in the pulp) were observed; however, ‘thinning’ was clearly superior in fruit weight. Thinning, rather than heading, was rated as a more advantageous summer pruning to produce this fig cultivar in terms of obtaining larger fruits.

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To prevent the deformation of pressurized food containers during temperature changes, retort pressure control methods are used to maintain an appropriate pressure within the container gas headspace. The simplest of these, known as the Taguchi method, involves manual control of the retort pressure based on the measured temperature within the container. There is, however, a lack of understanding concerning the applicability of various types of containers and retort methods, and selection of the location of temperature measurement and respective offset values proposed by Taguchi. This study resolved these issues and provides an explanation of them. Three types of plastic cups with different thicknesses of gelatinized starch were used. Temperature within the cups was measured in the central vertical direction during a thermal process in which the cups were heated to 120°C for 30 minutes using a hot-water shower-type retort. The pressure calculated based on the temperature of the air within the cups during the heating process showed better consistency with the measured pressure than that measured at other locations. During the cooling process, the pressure calculated from the temperature within the retort chamber was strongly consistent with the measured pressure. The reason why the chamber temperatures and offset values are used in the Taguchi pressure calculation is attributed to the good heat conductivity of the contained air.

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The effect of the air-containing part of food packages on the location of the minimum Fo value was investigated. A 6% gelatinized starch liquid was packed into a cylindrical cup also containing air, and the temperature was measured at six points on the central vertical axis during thermal processing at 120 °C for 30 minutes. As a result, the position where the Fo value was at a minimum was found to be closer to the air-containing part than to the geometric center of the cylinder. When the temperature curves at each position were analyzed using the delay time (δ) of the ATS method, it was confirmed that the minimum Fo value occurred where the temperature rise was slow and the cooling was fast. These minimum Fo values were approximately 10% to 15% of the Fo value at the geometric center position. It is thus necessary to consider the risks of an inadequate thermal treatment due to assuming an incorrect temperature measurement location by not taking air pockets into account.

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Various heme pigments, including myoglobin (Mb), hemoglobin, and cytochromes, are present in meat. These heme pigments can be used to evaluate meat color. An acetone–hydrochloric acid mixture (75:0.7) was used to extract and quantify heme pigments from a meat sample in the form of hematin. To evaluate color changes due to differences in meat pH, heme pigments were extracted from a variety of meat samples to determine whether the hydrochloric acid content could be adapted. A calibration curve was prepared based on the total amount of heme pigment extracted from Mb dissolved in a buffer solution (pH 4.1–11). No adverse effects, including reduced extraction efficiency or heme pigment decomposition, were observed at different pH values. The salt produced from the neutralization reaction during the extraction did not affect extraction efficiency. No differences in yield were observed between extraction solvents with varying proportions of hydrochloric acid (0.4–1.6 mL, 0.7–2.8%) for meat samples adjusted to pH 4.4 and unadjusted samples (pH 5.6–5.7). At pH 10.5, it tend to much the heme pigments were extracted with 1.4% hydrochloric acid, however with no significant differences in extraction yield from 0.7–1.4%. Therefore, 0.7% hydrochloric acid is suitable for extracting and quantifying all heme pigments in a meat sample.

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During meat processing, connective tissue and fat are often removed. Previous studies have reported that protease treatment (PrT) and quick-freezing treatment (QFT) effectively remove connective tissue and fat from beef tallow during cooking. This indicated that tissue removal may be unnecessary; however, its applicability to general meat remains unclear. In this study, the juice loss, nutritional components, and taste of PrT/QFT-treated grilled pork loin meat were compared with those of untreated loin. The results revealed that PrT/QFT facilitates the removal of connective tissue and fat, thereby reducing the fat content and enhancing the protein content. Additionally, sensory evaluation indicated that PrT/QFT significantly reduced greasiness without affecting the comprehensive preference. These results indicated that PrT/QFT can enhance the nutritional value and sensory quality of general meat products.

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The effects of polyphenols on the texture of gels prepared from Alaskan pollock (Gadus chalcogrammus) surimi were investigated. The breaking force and strain of the polyphenol-containing gels were dependent on the type and amount of added polyphenol. Gels with 0.1% tannic acid, 0.1% gallic acid, 0.1% ellagic acid, 0.05% catechin, and 1.0% naringenin showed increased breaking forces compared with gels lacking added polyphenols. In contrast, supplementation with polyphenols decreases gel breaking force and strain. A comparison of catechins with different structures showed that the strength of reactivity was not proportional to breaking force. The number of free sulfhydryl groups in gels with gallic acid or catechins suggests that these polyphenols induce binding through sulfhydryl groups. Mass spectrometry imaging of the gel with gallic acid suggested the formation of protein-gallic acid complexes. The increase in the breaking force was inferred to be related to formation of cross-links and complexes between polyphenols and proteins through sulfhydryl groups. To control protein gel texture, selection of appropriate polyphenol and protein concentrations is important.

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The majority of wine containers are “Glass bottles”, and when they are replaced with “Cans”, the flavor of the wine may deteriorate. Although hydrogen sulfide generation has been reported in patents and studies on canned wine, there are no studies reporting the detection of hydrogen sulfide in commercial canned wine. Therefore, understanding of this process remains unclear. We report here results of a wine analysis study conducted on commercially available foreign canned wine (white) using large volume headspace gas chromatography-mass spectrometry (GC-MS). Two methods were used for analysis. Hydrogen sulfide was only detected in the refrigerated samples. Because refrigerated samples change little over time, hydrogen sulfide was detected only in the early stages of storage and not as an off-flavor substance that occurs during long-term storage. The examined canned wines were stored at room temperature for over a year, but no off-flavors were detected, and the odor seemed to have diminished. It appears that it is important to check not only for substances that have increased as off-flavors, but also for substances that have decreased.

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