Enhancement of γ-aminobutyric acid content in shells of passion fruit (Passiflora edulis) under anoxic vacuum conditions.

Passiflora edulis, commonly known as passion fruit, is a popular all-weather fruit eaten fresh or processed. Its shells, which currently are mostly discarded as waste and hurt the environment, account for more than half of the passion fruit. The shells contain gamma-aminobutyric acid (GABA) which is the main inhibitory neurotransmitter and has many proven medical values such as antidepressant, anti-anxiety, etc. Many studies have shown that GABA production in plants can be significantly increased by reverse stress. Taking Tainong 1 as a typical passion fruit cultivar, this study explored the optimal anoxic vacuum treatment for increasing the GABA content of passion fruit shells. The content increased to 2139.25 ± 26.69 mg/100 g on day 4 of chill storage after vacuum packing (63.68% higher than the control). The activities of glutamate decarboxylase (GAD) and diamine oxidase (DAO) were significantly higher in the vacuum-treated group than in the control group after 4 days of vacuum-chill storage. On day 5 of vacuum-chill storage, the activities of all measured enzymes decreased except for the increase of GABA transaminase (GABA-T), which was accompanied by a decrease in GABA content. Vacuum treatment and subsequent chill storage increased the content of GABA, thereby increasing functional value of passion fruit shells.

Evaluating the Anti-Inflammatory and Antioxidant Effects of Broccoli Treated with High Hydrostatic Pressure in Cell Models.

Isothiocyanates (ITCs) are important functional components of cruciferous vegetables. The principal isothiocyanate molecule in broccoli is sulforaphane (SFN), followed by erucin (ERN). They are sensitive to changes in temperature, especially high temperature environments where they are prone to degradation. The present study investigates the effects of high hydrostatic pressure on isothiocyanate content, myrosinase activity, and other functional components of broccoli, and evaluates its anti-inflammatory and antioxidant effects. Broccoli samples were treated with different pressures and for varying treatment times; 15 min at 400 MPa generated the highest amounts of isothiocyanates. The content of flavonoids and vitamin C were not affected by the high-pressure processing strategy, whereas total phenolic content (TPC) exhibited an increasing tendency with increasing pressure, indicating that high-pressure processing effectively prevents the loss of the heat-sensitive components and enhances the nutritional content. The activity of myrosinase (MYR) increased after high-pressure processing, indicating that the increase in isothiocyanate content is related to the stimulation of myrosinase activity by high-pressure processing. In other key enzymes, the ascorbate peroxidase (APX) activity was unaffected by high pressure, whereas peroxidase (POD) and polyphenol oxidase (PPO) activity exhibited a 1.54-fold increase after high-pressure processing, indicating that high pressures can effectively destroy oxidases and maintain food quality. With regards to efficacy evaluation, NO production was inhibited and the expression levels of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 (COX-2) were decreased in broccoli treated with high pressures, whereas the cell viability remained unaffected. The efficacy was more significant when the concentration of SFN was 60 mg·mL-1. In addition, at 10 mg·mL-1 SFN, the reduced/oxidized glutathione (GSH/GSSG) ratio in inflammatory macrophages increased from 5.99 to 9.41. In conclusion, high-pressure processing can increase the isothiocyanate content in broccoli, and has anti-inflammatory and anti-oxidant effects in cell-based evaluation strategies, providing a potential treatment strategy for raw materials or additives used in healthy foods.

The effect of high-pressure processing on reducing the glycaemic index of atemoya puree.

BACKGROUND: This study investigated the effects of high-pressure processing (HPP) on the glycaemic index (GI) of atemoya puree (AP) in rats. Sprague-Dawley rats were fed with unprocessed and high-pressure processed atemoya puree (HPP-AP), and the GIs for the unprocessed AP and HPP-AP were calculated from changes in blood glucose concentrations within 2 h after meals. The physicochemical properties of AP were analysed to understand the mechanism affecting its GI. RESULTS: The results showed that HPP (600 MPa for 15 min) could delay increase in postprandial blood glucose levels, decrease the peak value of postprandial blood glucose by 76.1%, and significantly decrease the GI of AP to 49.8 in the experimental group compared to 65.4 in the control group. HPP did not exert a significant effect on the glucose and pectin contents of AP, but it increased the viscosity of the puree and its dietary fibre content and delayed the time of peak glucose response. In the analysis of enzymes of the puree, we found that HPP significantly decreased the activities of sucrose invertase, pectin methylesterase and polygalacturonase, thereby decreasing the rate of glucose generation in the puree and stabilizing the pectin structure, which decreased the absorption of glucose by the small intestine, thus decreasing the GI value. CONCLUSION: Our findings suggest that HPP technology could effectively delay increase in postprandial blood glucose levels and decrease the GI value of AP, thus having a potential application in developing atemoya puree products with low GI. © 2020 Society of Chemical Industry.

Increasing γ-Aminobutyric Acid Content in Vegetable Soybeans via High-Pressure Processing and Efficacy of Their Antidepressant-Like Activity in Mice.

This study applied high-pressure processing (HPP) technology to enrich the gamma aminobutyric acid (GABA) content in vegetable soybeans and evaluated its antidepressant efficacy on mice, with depression induced by the unpredictable chronic mild stress (UCMS) model. The optimal conditions for HPP, storage time, and storage temperature, as well as antidepressant-like effects of vegetable soybeans, were evaluated and discussed. HPP could effectively and significantly increase GABA content in soybean, with optimum conditions at 200 MPa. The GABA content in the whole vegetable soybean was 436.05 mg/100 g. In mice animal tests, the tail suspension test (TST) showed that the immobility time of the GABA group was significantly shorter than that of the control group. The total travel distance in the open field test (OFT) showed that depressed mice fed with the GABA feed exhibited exploratory behavior. The GABA group showed a significantly higher degree of sucrose preference than the control group. Both results indicate that the GABA feed could effectively alleviate depressive symptomatology. Regarding biochemical parameters, the fecal and serum corticosterone (CORT) levels in the control group increased to 104.86 pg/mg after the onset of depression. In contrast, the fecal CORT level in the GABA group was significantly reduced to 23.98 pg/mg and was comparable to that in the control group (33.38 pg/mg). Reduced serum CORT level in the GABA group suggests an improvement in depressive symptomatology. The serotonin concentration was maintained in the GABA group after the induction of depression, suggesting its preventive activity. The HPP GABA-enriched soybeans exerted modulatory effects on the behaviors of depressed mice and displayed a potential for commercialization.

Quality changes in high hydrostatic pressure and thermal pasteurized grapefruit juice during cold storage.

This study evaluated the effects of high hydrostatic pressure (HHP) and thermal pasteurization (TP) on microbial counts, physicochemical properties, antioxidant characteristics, naringin and naringenin contents, and naringinase activity of grapefruit juice during 21 days cold storage period. Results showed that HHP and TP significantly decreased the total microbial, coliform, and yeast counts. No significant differences between HHP-treated grapefruit juice (600 MPa/5 min) and untreated fruit juice with respect to physicochemical properties such as total titratable acidity, pH, and total soluble solids was observed after 21 days of storage. Although HHP affected the colour and antioxidant characteristics of grapefruit juice, the extent of effect was significantly lower than that for TP-treated fruit juice. This demonstrated that HHP could better maintain the original flavour and quality of grapefruit juice compared to TP. In addition, 92% naringinase activity was maintained in HHP-600 group on Day 21, which increased the degradation of bitter naringin into non-bitter naringenin during the cold storage of grapefruit juice. In summary, HHP can simultaneously maintain the microbiological safety of grapefruit juice along with its original quality characteristics. HHP can effectively extend the storage period and safety during cold chain transport, and hence highly applicable in the grapefruit juice industry.

Characterization of candidate genes involved in halotolerance using high-throughput omics in the halotolerant bacterium Virgibacillus chiguensis.

We previously used whole-genome sequencing and Tn5 transposon mutagenesis to identify 16 critical genes involved in the halotolerance of Halomonas beimenensis, a species in the phylum Proteobacteria. In this present study, we sought to determine if orthologous genes in another phylum are also critical for halotolerance. Virgibacillus spp. are halotolerant species that can survive in high-saline environments. Some Virgibacillus species are used in different aspects of food processing, compatible solute synthesis, proteinase production, and wastewater treatment. However, genomic information on Virgibacillus chiguensis is incomplete. We assembled a draft V. chiguensis strain NTU-102 genome based on high-throughput next-generation sequencing (NGS) and used transcriptomic profiling to examine the high-saline response in V. chiguensis. The V. chiguensis draft genome is approximately 4.09 Mbp long and contains 4,166 genes. The expression profiles of bacteria grown in 5% and 20% NaCl conditions and the corresponding Gene Ontology (GO) and clusters of orthologous groups (COG) categories were also analyzed in this study. We compared the expression levels of these 16 orthologs of halotolerance-related genes in V. chiguensis and H. beimenensis. Interestingly, the expression of 7 of the 16 genes, including trkA2, smpB, nadA, mtnN2, rfbP, lon, and atpC, was consistent with that in H. beimenensis, suggesting that these genes have conserved functions in different phyla. The omics data were helpful in exploring the mechanism of saline adaptation in V. chiguensis, and our results indicate that these 7 orthologs may serve as biomarkers for future screening of halotolerant species in the future.

Revealing the Saline Adaptation Strategies of the Halophilic Bacterium Halomonas beimenensis through High-throughput Omics and Transposon Mutagenesis Approaches.

Studies on the halotolerance of bacteria are attractive to the fermentation industry. However, a lack of sufficient genomic information has precluded an investigation of the halotolerance of Halomonas beimenensis. Here, we describe the molecular mechanisms of saline adaptation in H. beimenensis based on high-throughput omics and Tn5 transposon mutagenesis. The H. beimenensis genome is 4.05 Mbp and contains 3,807 genes, which were sequenced using short and long reads obtained via deep sequencing. Sixteen Tn5 mutants with a loss of halotolerance were identified. Orthologs of the mutated genes, such as nqrA, trkA, atpC, nadA, and gdhB, have significant biological functions in sodium efflux, potassium uptake, hydrogen ion transport for energy conversion, and compatible solute synthesis, which are known to control halotolerance. Other genes, such as spoT, prkA, mtnN, rsbV, lon, smpB, rfbC, rfbP, tatB, acrR1, and lacA, function in cellular signaling, quorum sensing, transcription/translation, and cell motility also shown critical functions for promoting a halotolerance. In addition, KCl application increased halotolerance and potassium-dependent cell motility in a high-salinity environment. Our results demonstrated that a combination of omics and mutagenesis could be used to facilitate the mechanistic exploitation of saline adaptation in H. beimenensis, which can be applied for biotechnological purposes.

Antioxidant properties of certain cereals as affected by food-grade bacteria fermentation.

The effects of fermentation by 2 food-grade bacteria (Bacillus subtilis and Lactobacillus plantarum) on antioxidant activities and the contents of phenolics and flavonoids in 4 cereals (specifically adlay, chestnut, lotus seed, and walnut) were determined and compared with those of their non-fermented counterparts. Results showed that antioxidant properties observed in the fermented and non-fermented cereals may vary with fermented starters. Fermentation was observed to increase the phenolic and flavonoid contents of the extracts. The effects on Bacillus-fermented cereals were stronger than on Lactobacillus-fermented cereals. In IC50 values (mg/mL) of extracts, the extracts of fermented cereal showed a stronger DPPH radical scavenging and ferric-reducing activities. Fermentation did not significantly alter the Fe(2+)-chelating activity in the extracts of chestnuts and lotus seeds. All cereals were shown significantly inhibited the production of LPS-induced intracellular reactive oxygen species (ROS) without creating obvious cytotoxic effects in the macrophage cells. These results suggest that the fermentation process enables cereal-based foods with enhanced antioxidant capacities to contribute to health and nutritional improvements in consumers.

Halomonas beimenensis sp. nov., isolated from an abandoned saltern.

A Gram-staining negative, motile, non-spore-forming, short rod-shaped (0.8-1.5 × 1.5-2.0 µm), halophilic bacterium, designated strain NTU-107(T), was isolated from brine samples collected from the abandoned Beimen saltern in southern Taiwan. The novel strain grew with 0-15% (w/v) NaCl (optimum between 5% and 10%), at 15-55 °C (optimum 40 °C) and at pH 5.5-9.5 (optimum pH 7.5). The major cellular fatty acids were C(18:1)ω7c, C(16:0) and C(19:0 )cyclo ω8c, the genomic DNA G+C content was 66.5 mol%, and the predominant ubiquinone was Q-9. The major polar lipids included phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. In a phylogenetic analysis based on 16S rRNA gene sequences, strain NTU-107(T) clustered with members of the genus Halomonas. In hybridization experiments, however, the levels of DNA-DNA relatedness between strain NTU-107(T) and the type strains of its closest phylogenetic neighbours (Halomonas koreensis, H. organivorans and H. ventosae) were all found to be less than 40 %. Based on the phenotypic, chemotaxonomic and genetic data, strain NTU-107(T) represents a novel species within the genus Halomonas, for which the name Halomonas beimenensis sp. nov. is proposed. The type strain is NTU-107(T) ( = BCRC 17999(T) = KCTC 22876(T) = JCM 16084(T)).

Free radical-scavenging and tyrosinase-inhibiting activities of extracts from sorghum distillery residue.

This study evaluated the potential free radical-scavenging and tyrosinase-inhibiting activities of extracts from sorghum distillery residue (SDR). The results demonstrated that methanol was a more efficient solvent for extracting the active components of SDR, and methanol extracts showed the highest radical-scavenging and tyrosinase-inhibiting activities.

Lactic acid bacterial fermentation on the production of functional antioxidant herbal Anoectochilus formosanus Hayata.

This study evaluated a novel use of the traditional Asian herb Anoectochilus formosanus. This plant is a traditional food item, generally used for the treatment of liver disorder, hepatitis, hypertension, diabetes, cardiovascular disorder, etc. In this study, the root, stem, and leaf of A. formosanus were used as substrates for lactic fermentation. The fermentation products were analyzed for their total antioxidant activity, reducing power, and scavenging effect on superoxide anion radicals and hydrogen peroxide. The pH of the fermentation medium reached its lowest value, 3.5, at the 35th hour of fermentation. Antioxidant activity of A. formosanus was found to be 61-78%. Lactobacillus longum-led fermentation exhibited the greatest reducing power with an average of 0.3. The products of fermentations utilizing the three plant parts as substrates exhibited a similar scavenging activity (27-30%) on free radicals. This study may suggest a novel use of lactic-fermenting A. formosanus in the production of functional food.

Probiotic properties of Lactobacillus strains isolated from the feces of breast-fed infants and Taiwanese pickled cabbage.

This study assessed potential probiotic Lactobacillus strains isolated from the feces of breast-fed infants and from Taiwanese pickled cabbage for their possible use in probiotic fermented foods by evaluating their (i) in vitro adhesive ability, resistance to biotic stress, resistance to pathogenic bacteria, and production of ß-galactosidase; (ii) milk technological properties; and (iii) in vivo adhesive ability, intestinal survival and microbial changes during and after treatment. Five Lactobacillus isolates identified as Lactobacillus reuteri F03, Lactobacillus paracasei F08, Lactobacillus rhamnosus F14, Lactobacillus plantarum C06, and Lactobacillus acidophilus C11 that showed resistance to gastric juice and bile salts were selected for further evaluation of their probiotic properties. All the strains demonstrated the ability to adhere to Caco-2 cells, particularly, strain L. plantarum C06 and L. reuteri F03 showed satisfactory abilities, which were similar to that of the reference strain L. rhamnosus GG. The strains L. paracasei F08 and L. acidophilus C11 had the highest ß-galactosidase activity. Most of the strains were resistant to aminoglycosides and vancomycin but sensitive to ampicillin, erythromycin, and penicillin. All the 5 strains elicited antibacterial activity against both Gram-positive (Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus) and -negative (Escherichia coli and Salmonella enterica) pathogens. Moreover, the strains L. reuteri F03, L. paracasei F08, and L. plantarum C06 could grow rapidly in milk without nutrient supplementation and reached 108 cfu/mL after 24 h of fermentation at 37 °C. The viable cell counts of the 3 strains remained above 107 cfu/mL after 21 d of storage at 4 °C. In the animal feeding trial, the number of intestinal lactobacilli increased significantly after administration of milk fermented with the 3 strains, and the counts of fecal coliforms and Clostridium perfringens were markedly reduced. Lactobacillus strains could also survive in the ileal intestinal tissue of the treated rats. Technologically interesting Lactobacillus isolates may be used in the future as probiotic starter cultures for manufacturing novel fermented foods.

An analysis of feasibility of bioethanol production from Taiwan sorghum liquor waste.

In order to evaluate the feasibility of using sorghum liquor waste for bioethanol production, we serially investigated the effectiveness of physical treatment, microwave irradiation pretreatment, enzymatic hydrolysis, and fermentation. Composition analysis revealed that Kinmen sorghum liquor waste (KS) and Chiayi sorghum liquor waste (CS) contain approximately 17.2+/-0.7% and 18.2+/-0.6% cellulose, 19.0+/-0.6% and 21.6+/-1.0% hemicellulose, 18.5+/-0.8% and 20.6+/-1.7% acid detergent lignin, and 22.1+/-0.7% and 23.3+/-0.4% starch, respectively, on dry weight basis. The reducing sugar yield obtained after microwave irradiation pretreatment and enzymatic hydrolysis of KS and CS were 331.1 and 341.3mg/g dry weight. The ethanol yields obtained after fermentation of KS and CS hydrolysates with Saccharomyces cerevisiae were 0.13 and 0.14 g/g dry weight, respectively. This operation of pretreatment may provide a suggestible pattern of utilizing feedstock that contain lignocellulose and starchy for ethanolic fermentation.

Marinobacter szutsaonensis sp. nov., isolated from a solar saltern.

A Gram-negative, aerobic, non-spore-forming, halophilic bacterial strain, NTU-104(T), was isolated from the Szutsao saltern in southern Taiwan, which was previously used as salt production field. The novel isolate grew optimally at 35-40 degrees C, at pH 7.5-8.0 and in the presence of 5 % (w/v) NaCl. The major fatty acids were C(16 : 0), C(18 : 1)omega9c, C(16 : 1)omega9c, C(12 : 0) 3-OH and C(12 : 0). The predominant quinone was Q-9. Phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine were the predominant polar lipids. The DNA G+C content was 56.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed the affiliation of the novel isolate to the genus Marinobacter. DNA-DNA hybridization results between strain NTU-104(T) and the type strains of the most closely related species, Marinobacter pelagius and Marinobacter koreensis, were 36.4 % and 33.2 %, respectively. On the basis of phenotypic, phylogenetic and genetic analyses, strain NTU-104(T) is considered to represent a novel species of the genus Marinobacter. The name Marinobacter szutsaonensis sp. nov. is proposed, with strain NTU-104(T) (=BCRC 17809(T)=CGMCC 1.7011(T)=JCM 15751(T)) as the type strain.

Probiotic potential of noni juice fermented with lactic acid bacteria and bifidobacteria.

The present study assesses the feasibility of noni as a raw substrate for the production of probiotic noni juice by lactic acid bacteria (Lactobacilluscasei and Lactobacillus plantarum) and bifidobacteria (Bifidobacteriumlongum). Changes in pH, acidity, sugar content, cell survival and antioxidant properties during fermentation were monitored. All tested strains grew well on noni juice, reaching nearly 109 colony-forming units/ml after 48 h fermentation. L.casei produced less lactic acid than B.longum and L. plantarum. After 4 weeks of cold storage at 4°C, B.longum and L. plantarum survived under low-pH conditions in fermented noni juice. In contrast, L.casei exhibited no cell viability after 3 weeks. Moreover, noni juice fermented with B.longum had a high antioxidant capacity that did not differ significantly (P <0.05) from that of lactic acid bacteria. Finally, we found that B.longum and L. plantarum are optimal probiotics for fermentation with noni juice.

Virgibacillus chiguensis sp. nov., a novel halophilic bacterium isolated from Chigu, a previously commercial saltern located in southern Taiwan.

A Gram-positive, motile, endospore-forming, irregular rod-shaped (0.7-0.9 x 2.5-5.0 microm), halophilic bacterial strain, NTU-101(T), was isolated from Chigu saltern in southern Taiwan, previously used as a salt production field. The isolate was characterized taxonomically based on biochemical and molecular approaches. It grows optimally at 40 degrees C and in the presence of 5-10 % NaCl. Strain NTU-101(T) has cell-wall peptidoglycan based on meso-diaminopimelic acid and MK-7 as the predominant menaquinone. Major polar lipids are phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. Anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0) are the major fatty acids. The DNA G+C content was 37.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed its affiliation to the genus Virgibacillus. DNA-DNA relatedness values between strain NTU-101(T) and Virgibacillus dokdonensis and Virgibacillus pantothenticus were 17.5 and 21.5 %, respectively. Based on the phenotypic and phylogenetic properties, strain NTU-101(T) (=BCRC 17637(T)=CGMCC 1.6496(T)) was classified as a novel strain of Virgibacillus species, for which the name Virgibacillus chiguensis sp. nov. is proposed.

Antioxidant and antimicrobial activity of Zingiberaceae plants in Taiwan.

The rhizomes of the Zingiberaceae family are a vegetable widely used in many Asian countries, and their medicinal functions have been broadly discussed and accepted in many traditional recipes. In this study, 18 species of five genus of Zingiberaceae plants from Taiwan area were collected and analyzed for their functional properties. Methanolic extracts of the plants were analyzed for their total phenol compounds, alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) scavenging activity, and reducing power. Antimicrobial activity of these samples was also determined. The results showed that the total phenol compounds of the Alpinia genus averaged 17, 30 mg/g for Curcumas, and the highest, 36.5 mg/g for Vanoverberghia sasakiana. Antioxidant performances were best observed in Vanoverberghia and Hedychium, both 89%, and DPPH scavenging activity followed similar trends. Particularly, Zingiber oligophyllum, considered as a traditional medicinal plant used in Taiwan exhibited low DPPH scavenging activity and reducing power. Most Zingiberaceae plant extracts exhibited antimicrobial activity against all tested food microorganisms. Hedychium and Vanoverberghia, did not show antimicrobial activities on Escherichia coli and Vibrio parahaemolyticus. This study is a positive demonstration of the utility of screening Taiwan's endemic Zingiberaceous plants for their food and medicinal uses.

Microbial diversity analysis of former salterns in southern Taiwan by 16S rRNA-based methods.

The microbiota diversity of the former salterns in southern Taiwan was investigated by denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH). Soil samples from three salterns were analyzed using DGGE and 16S rRNA from 502 colonies representing 5 archaea and 18 bacteria taxonomic groups. Each representative taxonomic group was further identified, whereas 8.7% of clones were unclassified microorganisms. Chromohalobacter, Halomonas and Virgibacillus are dominant in the Biemen saltern, Chiguensis saltern and Szutsau saltern, respectively. During FISH analysis, several taxonomic-specific probes were used. The DAPI-stained-cell count in the Szutsao saltern had a higher number of microorganisms (4.58 x 10(7) cell/cm(3)) than the other salterns. Archaea occupied 2.7-6.6% whereas bacteria accounted for 37.2-52.9% of total microbial population at the three sites. Among these three sampling sites, the Szutsao saltern had the highest diversity in halophilic microbial composition, as indicated by DGGE and FISH.