Published Papers - TAKARA Kensaku

Determination of sotolon, sotolon precursors, and minerals in Okinawan awamori

Takara Kensaku, Soga Azusa, Irei Kotomi, Toguchi Shunpei, Asikin Yonathan, Wada Koji

Food Science and Technology Research ( 公益社団法人 日本食品科学工学会 )  31 ( 3 ) 223 - 232   2025 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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<p>Sotolon (3-hydroxy-4,5-dimethyl-2(5H)-furanone) is a volatile aroma compound with various desirable odors, including sweet, honey-like, and caramel-like. In this study, sotolon was quantified in 44 commercial awamori, an Okinawan rice-based distilled alcoholic beverage. Sotolon was detected at concentrations up to 20.5 µg ⁄ L, and awamori stored in earthenware jars had a significantly higher sotolon content than that in non-earthenware jars (p < 0.0001). Additionally, sotolon precursors (diacetyl, acetoin, acetaldehyde, and 2-oxobutyric acid) were present at concentrations of 0.13–1.48, 0.24–4.70, 77.50–332.50, and 0.16–0.96 mg ⁄ L, respectively, and showed no notable differences between storage vessels or periods. Moreover, Al and Cu were considerably higher in earthenware-jar-stored awamori, whereas Al, Cu, Fe, and Mn were markedly higher in aged awamori. These results suggest the possibility of mineral elution catalyzing the oxidation of sotolon precursors in earthenware jars and provide a foundation for further research on the mechanism of sotolon generation in awamori.</p>

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Characterization of Essential Oil Composition, Polymethoxyflavones, Total Carotenoids, and Sensory Properties of Japanese and Taiwanese Hirami Lemon (Citrus depressa Hayata).

Shimomura M, Tamura Y, Asikin Y, Oe M, Yamamoto M, Mitsube F, Lin SY, Arakaki M, Ayustaningwarno F, Takara K, Wada K

Journal of oleo science   75 ( 4 ) 465 - 476   2026 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Characterization of Volatile Organic Compounds in Citrus-Flavored Sesame, Palm, and Coconut Oils Using Gas Chromatography-Mass Spectrometry and Multivariate Analysis.

Ayu AM, Katherinatama A, Asikin Y, Oe M, Takara K, Anjani G, Afifah DN, Rustanti N, Ayustaningwarno F

Journal of food science ( Journal of Food Science )  90 ( 10 ) e70587   2025.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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ABSTRACT The incorporation of citrus‐based flavoring agents into vegetable oils has gained increasing attention because of their potential to enhance both the sensory and functional qualities. In this study, the aroma profiles of sesame, palm, and coconut oils flavored with three tropical citrus species, Kaffir lime (Citrus hystrix), Key lime (Citrus aurantifolia), and Nasnaran (Citrus amblycarpa), were investigated. Citrus‐flavored vegetable oils were prepared by blending various concentrations of fresh citrus slices (60%, 100%, and 140% w/v) with oils. Volatile organic compounds of the citrus‐flavored oils were analyzed using headspace gas chromatography–mass spectrometry. Monoterpene hydrocarbons, particularly limonene, β‐pinene, and β‐thujene, dominated the profiles (95.91%–99.88%), with Kaffir lime and Nasnaran contributing richer and more complex aroma profiles compared to Key lime. Coconut oil yielded the highest proportion of monoterpene hydrocarbons (ca. 99%), with minimal levels of other volatiles, which may be related to its medium‐chain saturated fatty acid content. In contrast, the other oils displayed greater chemical diversity, including esters, ketones, and pyrazines. Multivariate evaluations, such as hierarchical clustering and principal component analysis, demonstrated that the citrus type was the primary driver of volatile differentiation, surpassing the oil matrix and citrus concentration effects. Additionally, partial least squares–discriminant analysis highlighted ocimenes as key volatile markers responsible for volatile discrimination across oil types (VIP = 1.57–2.17). These findings underscore the importance of selecting appropriate citrus varieties and concentrations to differentiate volatile profiles of citrus‐flavored vegetable oils, provide novel insights into potent aroma–matrix interactions, and support the development of customized, naturally flavored oils for culinary and functional applications. Practical Applications Edible oils, such as sesame, palm, and coconut, can be utilized to extract volatile organic compounds from citrus fruits, resulting in citrus‐flavored vegetable oils with distinctive aroma profiles. The outcomes of this research can benefit both food producers and consumers looking for flavor‐enhanced, locally sourced vegetable oils.

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The Effect of Raw Sugar Addition on Flavor and Retronasal Olfaction Profiles of Processed Brown Sugar.

Asikin Y, Nakaza Y, Oe M, Arakaki E, Maeda G, Kaneda H, Takara K, Wada K

Foods (Basel, Switzerland) ( Foods )  14 ( 9 )   2025.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Processed brown sugar is produced by combining non-centrifugal cane sugar (NCS), raw sugar, and molasses. The present study aimed to examine the effects of NCS and raw sugar blending (10%:90%, 50%:50%, 75%:25%, and 90%:10%) on color traits, non-volatile and volatile compounds, retronasal aroma release, and sensory profiles of processed brown sugar, and hence, its flavor quality. The International Commission for Uniform Methods of Sugar Analysis (ICUMSA) color index and the +L* (brightness) and +b* (yellowness) color spaces were gradually altered upon the addition of raw sugar, with strong Pearson's negative correlations between the ICUMSA value and both color space indices (r = -0.9554 and r = -0.9739, respectively), causing a lighter color of the final product. Raw sugar addition also significantly reduced the concentration of non-volatile compounds, such as glucose and organic acids (p < 0.05). As the raw sugar proportion increased from 10 to 90%, the concentrations of total volatile compounds and Maillard reaction products (MRPs), such as pyrazines, furans, and furanones, also decreased significantly from 62.58 to 22.73 µg/100 g and 34.75 to 6.80 µg/100 g, respectively. Reduced intensities of ion masses of in-mouth and in-nose retronasal odors from volatile MRPs, as well as roasted aroma and richness properties, were observed in processed brown sugars with greater raw sugar content. Taken together, a higher proportion of raw sugar in processed brown sugar manufacturing enhances brightness while reducing acidity and aftertaste; however, increased NCS content results in darker products with greater roasted aroma and richness, affecting flavor quality.

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Volatile Organic Components and MS-e-nose Profiles of Indonesian and Malaysian Palm Sugars from Different Plant Origins

Katherinatama, A; Asikin, Y; Amano, R; Hajar-Azhari, S; Yudianto, D; Widyahapsari, DAN; Widarta, IWR; Takara, K; Wada, K

CHEMOSENSORS ( Chemosensors )  13 ( 5 )   2025.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Volatile Component Composition, Retronasal Aroma Release Profile, and Sensory Characteristics of Non-Centrifugal Cane Sugar Obtained at Different Evaporation Temperatures

Asikin, Y; Nakaza, Y; Oe, M; Kaneda, H; Maeda, G; Takara, K; Wada, K

APPLIED SCIENCES-BASEL ( Applied Sciences (Switzerland) )  14 ( 24 ) 11617 - 11617   2024.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Non-centrifugal cane sugar (NCS) is prepared by evaporating sugarcane syrup to form a solidified, dehydrated brown sugar with a distinct flavor. This study investigated the effect of final evaporation temperatures (120–140 °C) on the volatile components, retronasal aroma profile, and sensory characteristics of NCS. Solid-phase microextraction–gas chromatography–mass spectrometry showed that the concentration of most volatiles, including pyrazines, furans, and furanones, in the NCS significantly increased as the evaporation temperature increased (p &lt; 0.05). The evaporation temperature affected the aroma release from NCS, as shown in proton transfer reaction time-of-flight-mass spectrometry, with the intensity of volatile compounds detected from panelists’ noses or mouths significantly increasing after consuming NCS obtained at higher temperatures. Moreover, the intensity of aroma release in the mouth was greater than that in the nose; the most prevalent released substance, m/z 87.10, which could be derived from dihydro-2(3H)-furanone and 2,3-butanedione, rapidly decreased over seven breath cycles compared to other ions, suggesting its importance as a top-note aroma substance in NCS. In addition, the perceived roasted aroma and bitterness of the NCS obtained at higher temperatures were intensified. These findings underscore the importance of modifying the evaporation temperature on the volatile component composition, aroma release, and sensory characteristics of NCS.

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Characterization of Free and Glycosidically Bound Volatile and Non-Volatile Components of Shiikuwasha (Citrus depressa Hayata) Fruit.

Katherinatama A, Asikin Y, Shimoda K, Shimomura M, Mitsube F, Takara K, Wada K

Foods (Basel, Switzerland) ( Foods )  13 ( 21 )   2024.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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In silico and in vitro Characterizations of Rodent Tuber (Typhonium flagelliforme) Mutant Plant Isolates against FXR Receptor on MCF-7 Cells.

Sianipar NF, Hadisaputri YE, Assidqi K, Salam S, Yusuf M, Destiarani W, Purnamaningsih R, So IG, Takara K, Asikin Y

Journal of Oleo Science ( 公益社団法人 日本油化学会 )  73 ( 10 ) 1349 - 1360   2024.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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<p><i>Typhonium flagelliforme</i> (<i>T. flagelliforme</i>) is an Indonesian rodent tuber plant traditionally used to treat cancer diseases. Although gamma-ray irradiation has been used to increase the content in the chemical compounds of the <i>T. flagelliforme</i> plants with anticancer activity ten times effective, the specific effect of the isolated compounds from the mutant plants has never been reported yet. The potential cytotoxic agents were characterized via nuclear magnetic resonance spectroscopy, infrared spectroscopy, and mass spectrometry as stigmasterol and 7α-hydroxyl stigmasterol; and their anticancer activity was investigated. The <i>in silico</i> biochemical profile of the two compounds were analyzed by molecular docking and molecular dynamics simulation to confirm its interaction with the agonist binding site of Farsenoid X receptor (FXR). Stigmasterol and 7α-hydroxyl stigmasterol can act as a competitive regulator with a high-affinity for the FXR. The results also showed that stigmasterol and 7α-hydroxyl stigmasterol were the most potential and active fraction of the <i>T. flagelliforme</i> mutant plant against the MCF-7 human breast cancer cell line, with IC ₅₀ value 9.13 µM and 12.97 µM, compared with cisplastin as a control about 13.20 µM. These results demonstrate the potential of stigmasterol and 7α-hydroxyl stigmasterol in <i>T. flagelliforme</i> mutant plants to act towards cancer diseases.</p>

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Genetic Characteristics and Volatile Organic Compounds of Leaves and Fruit Edible Parts of Citrus depressa Hayata from Different Geographic Origins

Moena Oe, Yonathan Asikin, Misaki Kashima, Masashi Yamamoto, Fumimasa Mitsube, Shu-Yen Lin, Kensaku Takara, Koji Wada

Horticulturae ( MDPI AG )  10 ( 9 ) 939 - 939   2024.09 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Citrus depressa Hayata is a citrus cultivar grown in Japan and Taiwan. To assess the differences in genetic characteristics and volatile organic components (VOCs) in the leaves and edible parts of the fruits of 23 C. depressa accessions from different geographic origins, the tissues were analyzed using cleaved amplified polymorphic sequence markers and gas chromatography-mass spectrometry. A phylogenetic cluster analysis demonstrated that Kagoshima accessions had a close genetic relationship with one another, with Okinawan “Izumi kugani-like” being the most distinct accession. The predominant volatiles in the leaves were γ-terpinene, p-cymene, limonene, and linalool. Multivariate analysis and volcano plots revealed distinct volatiles in the leaves of each cultivation region: piperitone and citronellal (Kagoshima); 5,9,9-trimethyl-spiro[3.5]non-5-en-1-one (Okinawa); and hexanal (Taiwan). Furthermore, the edible parts of Taiwanese fruits contained abundant amounts of monoterpenes, including linalool and 1,8-cineole. In contrast, Kagoshima and Okinawa accessions were rich in aldehydes and esters, respectively. In conclusion, the genetic and volatile profiles of 23 C. depressa accessions of different origins could be distinguished, and multivariate analysis suggested that C. depressa contains diverse VOCs depending on where it is cultivated. These findings demonstrate the exclusivity of C. depressa resources in each region, which could assist farmers and agro-industries in promoting food products derived from C. depressa fruits.

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Physicochemical, Carotenoid, Metabolite, and Volatile Organic Compound Profiling of Okinawan Shiikuwasha (Citrus depressa Hayata) and Calamansi (C. microcarpa Bunge)

Moena Oe, Yonathan Asikin, Fumimasa Mitsube, Yasuyo Sekiyama, Kensaku Takara, Koji Wada

Applied Sciences ( MDPI AG )  14 ( 15 ) 6746 - 6746   2024.08 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Shiikuwasha (Citrus depressa Hayata) and calamansi (C. microcarpa Bunge) are distinct citrus species with a strong sour taste that grow naturally in Okinawa, Japan. The present study aimed to characterize the physicochemical traits, total carotenoid content, and taste/nutrient-related metabolite and volatile organic compound (VOC) profiles of the mature fruits from three shiikuwasha cultivation lines (“Izumi kugani”, “Izumi kugani-like”, and “Ogimi kugani”) and calamansi. The shiikuwasha lines had higher ratios of soluble solids/titratable acidity but a lower total carotenoid content than calamansi. There were positive statistical correlations between total carotenoids with red, yellow, and orange indices (a*, b*, and a*/b* color spaces, respectively). Principal component analysis (PCA) revealed that shiikuwasha had higher sucrose and choline contents, while calamansi was richer in sourness-related metabolites such as citrate and malate. PCA plots displayed differences in the VOCs between the two citrus cultivars, wherein volatile accumulation was much richer in juices prepared from the whole fruits than in juices from the edible flesh parts. The plots also showed that monoterpenes and sesquiterpenes differentiated the VOC profiles of shiikuwasha and calamansi. This study reveals differences in the flavor components of the two citrus cultivars and highlights the potential uses of each in local and regional agro-business.

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Verification of In Vitro Anticancer Activity and Bioactive Compounds in Cordyceps Militaris-Infused Sweet Potato Shochu Spirits.

Sakao K, Sho C, Miyata T, Takara K, Oda R, Hou DX

Molecules (Basel, Switzerland) ( Molecules (Basel, Switzerland) )  29 ( 9 )   2024.05 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Gas chromatography-mass spectrometry-based electronic nose, glycosidically bound volatile, and alcohol-acyltransferase activity profiles of Okinawan pineapple

Asikin, Y; Kohama, A; Kudaka, T; Maekawa, R; Kobayashi, T; Takeuchi, M; Kamiyoshihara, Y; Takara, K; Wada, K

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY ( International Journal of Food Science and Technology )  59 ( 10 ) 7932 - 7941   2024.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Summary A recent increase in the demand for pineapple necessitates the development of new varieties with superior flavour quality. In this study, we characterised the volatile profiles of three new Okinawan pineapple breeding lines using gas chromatography (GC)–mass spectrometry (MS)‐based electronic nose (e‐nose), glycosylated volatiles, and alcohol‐acyltransferase (AAT) activity measurements. The volatile profiles of the fruits were selected using the GC–MS‐e‐nose and visualised using multivariate statistical plots. The glycosidically bound compounds were collected by solid‐phase extraction and hydrolysed by β‐glucosidase. In total, 12 hydroxyl‐group substances, including chavicol (medicinal‐herbal aroma), geraniol (floral‐sweet), and linalool (floral‐citrus), were released from these glycosides. Crude enzymes containing AAT were extracted, and their in vitro activities in 2‐methylbutyl acetate production were highly related to their contents. These results provide information regarding volatile profiles and bounded‐aroma resources, as well as the esterification potential of new Okinawan pineapple breeding lines for use in the agro‐food industry.

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Assessment of Volatile Characteristics of Okinawan Pineapple Breeding Lines by Gas-Chromatography-Mass-Spectrometry-Based Electronic Nose Profiling and Odor Activity Value Calculation

Asikin, Y; Kawahara, M; Kochi, S; Maekawa, R; Omine, Y; Takeuchi, M; Takara, K; Wada, K

CHEMOSENSORS ( Chemosensors )  11 ( 10 ) 512 - 512   2023.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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The recent increase in demand for Okinawan pineapples has necessitated the development of new varieties with attractive aromas. This study aimed to evaluate the volatile characteristics of five Okinawan pineapple breeding lines, i.e., ‘No. 22’, ‘No. 25’, ‘No. 26’, ‘No. 27’, and ‘No. 28’. The total volatiles in the cryopulverized fruit flesh were examined using headspace gas-chromatography–mass-spectrometry-based electronic nose analysis. The total ion masses of the volatiles were visualized using principal component analysis, and three replicates of each line with comparable volatile characteristics were selected. Furthermore, the composition of the volatile components in these replicates was assessed, and the odor activity values (OAVs) were calculated. The breeding lines varied in the quantity and composition of their volatile compounds, which were predominantly esters, ketones, terpenes, and alcohols. The ‘No. 22’ fruit contained a greater content of volatiles than the other lines. Moreover, 14 volatiles with OAV &gt; 1 were accounted as aroma-active compounds, and their variations were distinguished as follows: the highest OAV (786.96) was recorded for methyl 2-methylbutanoate of the ‘No. 26’ line; 2,5-dimethyl-4-methoxy-3(2H)-furanone was superior in the ‘No. 26’ and ‘No. 27’ lines; and δ-decalactone was only present in the ‘No. 22’ and ‘No. 27’ fruits, suggesting different potent practical uses for these new breeding lines.

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Multivariate Profiling of Metabolites and Volatile Organic Compounds in Citrus depressa Hayata Fruits from Kagoshima, Okinawa, and Taiwan.

Asikin Y, Tamura Y, Aono Y, Kusano M, Shiba H, Yamamoto M, Mitsube F, Lin SY, Takara K, Wada K

Foods (Basel, Switzerland) ( Foods )  12 ( 15 ) 2951   2023.08 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Evaporation Temperature Alters Physicochemical Characteristics and Volatile Maillard Reaction Products of Non-Centrifugal Cane Sugar (NCS): Comparison of Polyethylene Membrane and Retronasal Aroma Simulator Techniques for the Extraction of Volatile Organic Compounds in NCS

Yonathan Asikin, Yuki Nakaza, Goki Maeda, Hirotaka Kaneda, Kensaku Takara, Koji Wada

Applied Sciences ( MDPI AG )  13 ( 11 ) 6402 - 6402   2023.05 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Non-centrifugal cane sugar (NCS) is produced from sugarcane syrup via thermal evaporation. This study aimed to assess the effects of different temperatures during the evaporation process on the physicochemical characteristics and Maillard reaction products (MRPs) of NCS. Evaporation was tested at three final heating temperatures (120, 130, and 140 °C). The moisture content, water activity, L*a*b* color spaces, and ICUMSA (International Commission for Uniform Methods of Sugar Analysis) values of the NCS were determined. Volatile MRPs of NCS were extracted using polyethylene (PE) membrane and retronasal aroma simulator (RAS) techniques, and their components were measured using gas chromatography. A higher evaporation temperature produced NCS with less moisture content and water activity. However, it also led to a darker color, as indicated by lower L* (brightness) and b* (yellow) values in the color spaces. Additionally, higher evaporation temperatures resulted in greater ICUMSA values. Moreover, higher heating increased the amounts of volatile MRPs, such as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2-furanmethanol, 2-methylpyrazine, 2,5-dimethylpyrazine, and 2,6-dimethylpyrazine. Negative correlations were observed between moisture content, water activity, brightness, yellow color, and the total MRPs obtained by PE and RAS extractions. Additionally, positive and significant correlations were confirmed between ICUMSA values and most MRPs. Thus, the evaporation temperature alters the key physicochemical traits and volatile compounds of NCS, affecting its physical stability and flavor quality.

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Composition of Minerals and Volatile Organic Components of Non-Centrifugal Cane Sugars from Japan and ASEAN Countries.

Ayustaningwarno F, Asikin Y, Amano R, Vu NT, Hajar-Azhari S, Anjani G, Takara K, Wada K

Foods (Basel, Switzerland) ( Foods )  12 ( 7 ) 1406 - 1406   2023.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Non-centrifugal cane sugar (NCS) is an unrefined dehydrated form of sugar syrup produced worldwide. To date, there is a lack of differentiation in the key nutrients and flavor qualities of NCS products among countries, which makes it difficult for interested parties to select NCSs suitable for their needs. This study aimed to evaluate the minerals and volatile organic components (VOCs) in NCS products from Japan and ASEAN countries. Mineral components were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). VOCs and their aroma profiles were examined using gas chromatography–mass spectrophotometry (GC-MS) and MS-e-nose analyses, respectively. The total minerals content in Japanese NCSs ranged from 228.58 to 1347.53 mg/100 g, comprising K, Ca, Mg, P, and Na (69.1, 16.6, 7.9, 4.5, and 3.2%, respectively); their average total amounts were as high as those of Malaysia and Indonesia origins (962.87, 984.67, and 928.47 mg/100 g, respectively). Forty-four VOCs were identified, of which concentrations of pyrazines, furans, and pyranones varied significantly among the NCSs. Additionally, the MS-e-nose analysis provided a multivariate differentiation profile of the NCS products based on differences in the intensities of the VOC ion masses. Nine statistical clusters were presented, wherein certain NCS products of ASEAN origin had volatile profiles comparable to those of the Japanese products. These outcomes suggest that the origin of production greatly influences the mineral and VOC compositions of NCS, affecting their quality traits.

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Free and Glycosidically Bound Volatile Compounds in Okinawan Pineapple (<i>Ananas comosus</i>)

Asikin Yonathan, Shimoda Kazuki, Takeuchi Makoto, Maekawa Ryota, Kamiyoshihara Yusuke, Takara Kensaku, Wada Koji

APPLIED SCIENCES-BASEL ( Applied Sciences (Switzerland) )  12 ( 19 ) 9522 - 9522   2022.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Fruit plants produce various volatile compounds that emit distinct aroma characteristics and contribute to their flavor qualities. However, some of these substances, especially hydroxyl-group molecules, are in non-volatile glycosylated forms. This study aimed to determine free and glycosidically bound volatile compounds in three Okinawan pineapple cultivars (‘N67-10’, ‘Yugafu’, and ‘Yonekura’). The free volatile components of squashed pineapple juice were analyzed using solid-phase microextraction (SPME)–arrow-gas chromatography–flame ionization detection/mass spectrometry (GC-FID/MS). The glycosides were collected through solid-phase extraction, hydrolyzed by β-glucosidase, and the released volatile compounds were measured. The sugar moieties of the glycosides were confirmed using GC-MS, and their glycoside constituents were analyzed using liquid chromatography (LC)-MS. Okinawan pineapple varied in its content and composition of free volatile components, which were predominantly comprised of esters, followed by alcohols, terpenes, and ketones. Eight hydroxyl-group compounds, including chavicol, eugenol, geraniol, phenylethyl alcohol, benzyl alcohol, 2-ethyl-1-hexanol, 1-hexanol, and 3-methyl-2-butenol, were released from their glycosylated forms via enzymatic hydrolysis, wherein the amounts of most of them were greater in ‘Yonekura’ than in the other cultivars. Moreover, two glycosides, chavicol-O-β-D-glucopyranoside and eugenol-O-β-D-glucopyranoside, were identified in all the cultivars, wherein the aglycones of both glycosides could be potential odor sources of the medicinal-herbal aromas. These results provide important information regarding both volatile-aroma qualities and bounded-aroma resources in Okinawan pineapple for fresh consumption and agroindustrial processing.

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Simple Quantitative Analysis of Gamma-Aminobutyric Acid in <i>Luffa aegyptiaca</i> Mill

Tsuchida Eito, Maeda Goki, Tanahara Naoya, Sawai Yusuke, Takara Kensaku, Wada Koji

Nippon Shokuhin Kagaku Kogaku Kaishi ( Japanese Society for Food Science and Technology )  69 ( 7 ) 361 - 367   2022 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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<p>The ingestion of agricultural products containing gamma-aminobutyric acid (GABA) may improve blood pressure conditions, as indicated by Foods with Function Claims entries. Recently, a modified <i>Luffa aegyptiaca</i> product was developed to have high GABA content. The objective of this study was to investigate the quantification of GABA levels in <i>Luffa aegyptiaca</i> by simple methods used in research and development and product quality assurance. The results showed a significant and strong positive correlation between the HPLC method and the enzymatic assay, suggesting that the use of an enzymatic assay for GABA quantification is equally as robust as the HPLC method.</p>

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Blood Pressure Lowering Effect of Sponge Gourd (<i>Luffa aegyptica</i> Mill.) Containing <i>γ</i>-aminobutyric Acid (GABA) in Spontaneously Hypertensive Rats and GABA Enrichment in Sponge Gourd Pickle

TAKARA Kensaku, OHNISHI Ryuko, WADA Koji, MAEDA Goki, TANAHARA Naoya, SAWAI Yusuke

Food Preservation Science ( Japan Association of Food Preservation Scientists )  48 ( 2 ) 51 - 57   2022 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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<p> Gamma-aminobutyric acid (GABA) is known for its blood pressure-lowering effect. We investigated this function in spontaneously hypertensive rats (SHR) on sponge gourd chronic administration and attempted to increase GABA concentration in sponge gourd via pickling. A single oral dose of GABA (5-mg/10-mℓ/kg) or sponge gourd extract (containing 2-mg GABA/10-mℓ/kg) significantly decreased SHR blood pressure after 6 h postadministration (<i>p</i><0.05). Compared to the control group, a significantly slower increase in blood pressure was observed after 7 to 10 weeks post GABA or gourd diet feeding (<i>p</i><0.01), and this difference was maintained throughout the entire administrations. However, the GABA content in cut sponge gourd was doubled by vacuum-packing followed by refrigeration for 3 days. Moreover, there was an increment in GABA concentration due to monosodium glutamate (MSG) addition on pickled lyophilized gourd powder upon heating at 60℃ for 15 min at pH 5.5. Additionally, the concentration was enhanced thrice when fresh gourd was soaked in 0.2% MSG solution, vacuum-packed, and heated at 60℃ for 15 min. Taken together, sponge gourd containing GABA could lower blood pressure on SHR and its GABA concentration could be enhanced by pickling preservation.</p>

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Relationship between the <i>γ</i>-Aminobutyric Acid (GABA) Content and the Different Fruit Parts, Number of Days after Pollination, and Harvest Time of Loofah (<i>Luffa aegyptiaca</i> Mill.)

MAEDA Goki, HIROSE Naoto, TSUCHIDA Eito, ONDA Satoshi, TANAHARA Naoya, TAMAKI Moritoshi, TAKARA Kensaku, WADA Koji

Food Preservation Science ( Japan Association of Food Preservation Scientists )  48 ( 5 ) 227 - 234   2022 [ Peer Review Accepted ]

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<p> Loofah (<i>Luffa aegyptiaca</i> Mill.) is an annual vine belonging to the family Cucurbitaceae that is native to Southeast Asia. The immature fruits of loofah are a popular traditional vegetable in the Okinawa Prefecture, Japan. We investigated the distribution of <i>γ</i>-aminobutyric acid (GABA) in loofah fruits. In addition, we also investigated the relationship between the GABA content in loofah and the harvest time. We found that the GABA content in loofah was higher in the placenta than that in the other parts of the fruit, and that the GABA content decreased with fruit enlargement after pollination. Furthermore, we found that loofahs on the market vary substantially in not only fruit length and diameter but also GABA content.</p>

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