The Experts below are selected from a list of 1686 Experts worldwide ranked by ideXlab platform
Dai Chen - One of the best experts on this subject based on the ideXlab platform.
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impact of simultaneous and sequential fermentation with torulaspora delbrueckii and saccharomyces cerevisiae on non volatiles and volatiles of Lychee wines
Lwt - Food Science and Technology, 2016Co-Authors: Dai Chen, Shaoquan LiuAbstract:Abstract This study evaluated the effects of simultaneous and sequential fermentation with Torulaspora delbrueckii PRELUDE and Saccharomyces cerevisiae MERIT.ferm non-volatile and volatile components of on Lychee wines. T. delbrueckii monoculture showed lower fermentative activity than S. cerevisiae alone with regard to growth, nitrogen utilization, production of alcohols, volatile acids and esters. However, T. delbrueckii monoculture had a better ability to retain the odour-active terpenes and terpenoids derived from Lychee fruits. The Lychee wine fermented with simultaneous culture had a similar characteristic to that of the S. cerevisiae monoculture. In sequential fermentation, prior inoculation of T. delbrueckii played an important role in lowering volatile acids (odour activity value, OAV S. cerevisiae significantly increased the production of ethanol (>8 mL/100 mL), higher alcohols (isoamyl alcohol and 2-phenylethyl alcohol) and esters (ethyl esters of octanoate, decanoate and hexanoate, and 2-phenylethyl acetate), relative to the T. delbrueckii monoculture. Therefore, sequential fermentation could accord the wine volatiles from both Lychee fruits and biotransformation.
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Evaluation of the performance of Torulaspora delbrueckii, Williopsis saturnus, and Kluyveromyces lactis in Lychee wine fermentation.
International journal of food microbiology, 2015Co-Authors: Dai Chen, Zhi Yin Yap, Shaoquan LiuAbstract:This study evaluated the effects of three non-Saccharomyces yeasts, namely Torulaspora delbrueckii PRELUDE, Williopsis saturnus NCYC22, and Kluyveromyces lactis KL71 on Lychee juice fermentation. The fermentation performance of these non-Saccharomyces yeasts was significantly different. T. delbrueckii PRELUDE had the fastest rate of growth and high sugar consumption. W. saturnus NCYC22 used the lowest amount of sugars, but consumed the highest amount of nitrogen. Correspondingly, strain PRELUDE produced the highest level of ethanol (7.6% v/v), followed by strain KL71 (3.4% v/v) and strain NCYC22 (0.8% v/v). Aroma character-impact terpenes and terpenoids could be partially retained in all Lychee wines, with higher odour activity values (OAVs) of geraniol and citronellol in strain KL71. However, strain KL71 and strain NCYC22 over-produced ethyl acetate. Strain PRELUDE had a better ability to generate high levels of ethanol, isoamyl alcohol, 2-phenylethyl alcohol, ethyl octanoate, and ethyl decanoate and retained high OAVs of Lychee aroma-character compounds cis-rose oxide (16.5) and linalool (3.5). Thus, it is deemed to be a promising non-Saccharomyces yeast for Lychee wine fermentation.
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impact of addition of aromatic amino acids on non volatile and volatile compounds in Lychee wine fermented with saccharomyces cerevisiae merit ferm
International Journal of Food Microbiology, 2014Co-Authors: Dai Chen, Jing Yee Chia, Shaoquan LiuAbstract:The impact of individual aromatic amino acid addition (L-phenylalanine, L-tryptophan and L-tyrosine) on non-volatile and volatile constituents in Lychee wine fermented with Saccharomyces cerevisiae var. cerevisiae MERIT.ferm was studied. None of the added amino acids had any significant effect on the yeast cell count, pH, soluble solid contents, sugars and ethanol. The addition of L-phenylalanine significantly reduced the production of pyruvic and succinic acids. The addition of each amino acid dramatically reduced the consumption of proline and decreased the production of glycerol. Supplementation of the Lychee juice with L-phenylalanine resulted in the formation of significantly higher amounts of 2-phenylethyl alcohol, 2-phenylethyl acetate, 2-phenylethyl isobutyrate and 2-phenylethyl hexanoate. In contrast, supplementation with L-tryptophan and L-tyrosine had negligible effects on the volatile profile of Lychee wines. These findings suggest that selectively adding amino acids may be used as a tool to modulate the volatile profile of Lychee wines so as to diversify and/or intensify wine flavour and style.
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Chemical and volatile composition of Lychee wines fermented with four commercial Saccharomyces cerevisiae yeast strains
International Journal of Food Science and Technology, 2013Co-Authors: Dai ChenAbstract:Summary This study evaluated the chemical and volatile composition of Lychee wines fermented with four commercial yeast strains of Saccharomyces cerevisiae: EC-1118, R2, 71B and MERIT.ferm. Yeast cell population, pH, malic acid, ammonia and some amino acids had significant differences between strain 71B and other strains. There were strain variations with regard to degradation and retention of some juice volatiles as well as formation of new volatile compounds such as most esters and certain terpene compounds. Ethyl octanoate had the highest odour activity value (OAV of 500–1100), followed by ethyl hexanoate (about 50–85), among the common odorants in all Lychee wines. Ethyl octanoate reached its highest OAV (1077) in the Lychee wine fermented with strain EC1118, whereas ethyl hexanoate had the highest OAV (85) in the wine fermented with strain MERIT.ferm. Cis-rose oxide, the character-impact volatile in Lychee juice with highest OAV (161), was dramatically reduced to trace levels after fermentation.
Shaoquan Liu - One of the best experts on this subject based on the ideXlab platform.
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impact of simultaneous and sequential fermentation with torulaspora delbrueckii and saccharomyces cerevisiae on non volatiles and volatiles of Lychee wines
Lwt - Food Science and Technology, 2016Co-Authors: Dai Chen, Shaoquan LiuAbstract:Abstract This study evaluated the effects of simultaneous and sequential fermentation with Torulaspora delbrueckii PRELUDE and Saccharomyces cerevisiae MERIT.ferm non-volatile and volatile components of on Lychee wines. T. delbrueckii monoculture showed lower fermentative activity than S. cerevisiae alone with regard to growth, nitrogen utilization, production of alcohols, volatile acids and esters. However, T. delbrueckii monoculture had a better ability to retain the odour-active terpenes and terpenoids derived from Lychee fruits. The Lychee wine fermented with simultaneous culture had a similar characteristic to that of the S. cerevisiae monoculture. In sequential fermentation, prior inoculation of T. delbrueckii played an important role in lowering volatile acids (odour activity value, OAV S. cerevisiae significantly increased the production of ethanol (>8 mL/100 mL), higher alcohols (isoamyl alcohol and 2-phenylethyl alcohol) and esters (ethyl esters of octanoate, decanoate and hexanoate, and 2-phenylethyl acetate), relative to the T. delbrueckii monoculture. Therefore, sequential fermentation could accord the wine volatiles from both Lychee fruits and biotransformation.
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Evaluation of the performance of Torulaspora delbrueckii, Williopsis saturnus, and Kluyveromyces lactis in Lychee wine fermentation.
International journal of food microbiology, 2015Co-Authors: Dai Chen, Zhi Yin Yap, Shaoquan LiuAbstract:This study evaluated the effects of three non-Saccharomyces yeasts, namely Torulaspora delbrueckii PRELUDE, Williopsis saturnus NCYC22, and Kluyveromyces lactis KL71 on Lychee juice fermentation. The fermentation performance of these non-Saccharomyces yeasts was significantly different. T. delbrueckii PRELUDE had the fastest rate of growth and high sugar consumption. W. saturnus NCYC22 used the lowest amount of sugars, but consumed the highest amount of nitrogen. Correspondingly, strain PRELUDE produced the highest level of ethanol (7.6% v/v), followed by strain KL71 (3.4% v/v) and strain NCYC22 (0.8% v/v). Aroma character-impact terpenes and terpenoids could be partially retained in all Lychee wines, with higher odour activity values (OAVs) of geraniol and citronellol in strain KL71. However, strain KL71 and strain NCYC22 over-produced ethyl acetate. Strain PRELUDE had a better ability to generate high levels of ethanol, isoamyl alcohol, 2-phenylethyl alcohol, ethyl octanoate, and ethyl decanoate and retained high OAVs of Lychee aroma-character compounds cis-rose oxide (16.5) and linalool (3.5). Thus, it is deemed to be a promising non-Saccharomyces yeast for Lychee wine fermentation.
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impact of addition of aromatic amino acids on non volatile and volatile compounds in Lychee wine fermented with saccharomyces cerevisiae merit ferm
International Journal of Food Microbiology, 2014Co-Authors: Dai Chen, Jing Yee Chia, Shaoquan LiuAbstract:The impact of individual aromatic amino acid addition (L-phenylalanine, L-tryptophan and L-tyrosine) on non-volatile and volatile constituents in Lychee wine fermented with Saccharomyces cerevisiae var. cerevisiae MERIT.ferm was studied. None of the added amino acids had any significant effect on the yeast cell count, pH, soluble solid contents, sugars and ethanol. The addition of L-phenylalanine significantly reduced the production of pyruvic and succinic acids. The addition of each amino acid dramatically reduced the consumption of proline and decreased the production of glycerol. Supplementation of the Lychee juice with L-phenylalanine resulted in the formation of significantly higher amounts of 2-phenylethyl alcohol, 2-phenylethyl acetate, 2-phenylethyl isobutyrate and 2-phenylethyl hexanoate. In contrast, supplementation with L-tryptophan and L-tyrosine had negligible effects on the volatile profile of Lychee wines. These findings suggest that selectively adding amino acids may be used as a tool to modulate the volatile profile of Lychee wines so as to diversify and/or intensify wine flavour and style.
Ruifen Zhang - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the phenolic profiles and physicochemical properties of different varieties of thermally processed canned Lychee pulp
RSC Advances, 2020Co-Authors: Zhineng Wang, Lihong Dong, Fei Huang, Bin Shu, Ruifen ZhangAbstract:Lychee pulp is rich in phenolics and has a variety of biological activities. However, the changes in the phenolic profile under heat treatment are unknown. The effect of the heat treatment temperature on commercial varieties (Guiwei and Nuomici) of canned Lychee was investigated by comparing samples that were either unheated (UH), underwent 70 °C heat treatment (HT70) or underwent 121 °C heat treatment (HT121) and then were stored at room temperature. The results showed that the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of the UH, HT70 and HT121 samples were significantly decreased after storage at room temperature for 9 d, 13 d and 25 d, respectively. However, the TPC, TFC and antioxidant activity of HT121 canned Lychee were still significantly higher than those of the UH and HT70 samples. However, the texture characteristics of the HT121 samples were worse than those of the UH and HT70 samples, and the color of the canned Lychee was darker after the HT121 treatment. Nine individual phenolic compounds were detected in the canned Lychee by HPLC-DAD. The gallic acid content was increased after HT121 treatment. In particular, (−)-gallocatechin was generated by HT121 thermal processing. However, after storage at room temperature for 9 d, the contents of (−)-gallocatechin in canned Guiwei and Nuomici were decreased by 96.27% and 94.04%, respectively, and (−)-gallocatechin disappeared after 25 d. In summary, the phenolic contents and antioxidant activity of canned Lychee are increased by high-temperature treatment.
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Effects of simulated digestion on the phenolic composition and antioxidant activity of different cultivars of Lychee pericarp.
BMC chemistry, 2019Co-Authors: Qing-zhu Zeng, Mingrui Dai, Xuejiao Cao, Xiong Xiong, Yang Yuan, Mingwei Zhang, Lihong Dong, Ruifen ZhangAbstract:Lychee pericarp is rich in phenolic and has good antioxidant activity. The effects of simulated gastric (SGF) and intestinal fluid (SIF) digestion on the contents, composition, and antioxidant activities of the phenolic substances in the pericarp of different Lychee cultivars (cv Jizui, Lizhiwang, Guiwei, Yuhe, Nuomici and Guihong) were investigated. Compared with distilled water (DW) treatment, the total phenolic content (TPC) and total flavonoid content (TFC) in the pericarp of different Lychee cultivars decreased after SGF digestion; especially, the TFC in “Lizhiwang” decreased by 41.5%. The TPC and TFC of Lychee pericarp also decreased after SIF digestion. However, the TPC in “Jizui”, “Guiwei” and “Yuhe” increased. The SGF and SIF also had different effects on the FRAP and ABTS antioxidant activities of different Lychee cultivars. The SGF digestion decreased the ABTS antioxidant capacity of Lychee pericarp but enhanced the FRAP value of some Lychee cultivars. However, the SIF digestion decreased the FRAP antioxidant activity of different Lychee cultivar pericarps but enhanced the ABTS antioxidant capacity of Lychee. The HPLC results showed that Lychee pericarp had relatively high contents of procyanidin B2 and procyanidin A2. After SIF digestion, caffeic acid and isoquercitrin could not be detected in any of the Lychee varieties. However, quercetin-3-rutinose-7-rhamnoside and isoquercitrin were increased after SGF digestion. Lychee pericarp could be used as an inexpensive functional food ingredient.
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Effects of simulated digestion on the phenolic composition and antioxidant activity of different cultivars of Lychee pericarp
BMC, 2019Co-Authors: Qing-zhu Zeng, Mingrui Dai, Xuejiao Cao, Xiong Xiong, Yang Yuan, Mingwei Zhang, Lihong Dong, Ruifen ZhangAbstract:Abstract Background Lychee pericarp is rich in phenolic and has good antioxidant activity. The effects of simulated gastric (SGF) and intestinal fluid (SIF) digestion on the contents, composition, and antioxidant activities of the phenolic substances in the pericarp of different Lychee cultivars (cv Jizui, Lizhiwang, Guiwei, Yuhe, Nuomici and Guihong) were investigated. Results Compared with distilled water (DW) treatment, the total phenolic content (TPC) and total flavonoid content (TFC) in the pericarp of different Lychee cultivars decreased after SGF digestion; especially, the TFC in “Lizhiwang” decreased by 41.5%. The TPC and TFC of Lychee pericarp also decreased after SIF digestion. However, the TPC in “Jizui”, “Guiwei” and “Yuhe” increased. The SGF and SIF also had different effects on the FRAP and ABTS antioxidant activities of different Lychee cultivars. The SGF digestion decreased the ABTS antioxidant capacity of Lychee pericarp but enhanced the FRAP value of some Lychee cultivars. However, the SIF digestion decreased the FRAP antioxidant activity of different Lychee cultivar pericarps but enhanced the ABTS antioxidant capacity of Lychee. The HPLC results showed that Lychee pericarp had relatively high contents of procyanidin B2 and procyanidin A2. After SIF digestion, caffeic acid and isoquercitrin could not be detected in any of the Lychee varieties. However, quercetin-3-rutinose-7-rhamnoside and isoquercitrin were increased after SGF digestion. Conclusions Lychee pericarp could be used as an inexpensive functional food ingredient
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Impact of thermal processing and storage temperature on the phenolic profile and antioxidant activity of different varieties of Lychee juice
LWT, 2019Co-Authors: Zhineng Wang, Lihong Dong, Ruifen Zhang, Fei Huang, Jia Xuchao, Mingwei ZhangAbstract:Abstract Lychee pulp is rich in phenolic compounds and has a variety of biological activities. However, their thermal stability are unknown. The results showed that after heat-treated at 121 °C (HT121), the total phenolic content (TPC) and total flavonoid content of the Lychee juices were significantly increased compared to those of the unheated (UH) and 70 °C heat-treated (HT70) Lychee juices. Nine individual phenolic compounds, gallic acid, (-)-gallocatechin, procyanidin B2, vanillic acid, quercetin-3-rutinose-7-rhamnoside, syringic acid, procyanidin A2, ferulic acid and rutin, were detected in Lychee juice by HPLC-DAD. After heat treatment at 121 °C and high temperature storage at 45 °C, the gallic acid content in Lychee juice was increased. In particular, (-)-gallocatechin was generated after thermal processing at 121 °C. (-)-Gallocatechin accounted for 89.50% of the total phenolic compounds in HT121 Lychee juice. However, with prolonged storage time (72 h) and increased storage temperature (45 °C), the (-)-gallocatechin degraded and disappeared. In summary, the thermal stability of most phenolic compounds in Lychee pulp is good, and heat treatment could promote the release of phenolic compounds in Lychee juice and improve their antioxidant activity. The variety of Guiwei Lychee is more suitable for fruit juice manufacturing.
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Structural elucidation and cellular antioxidant activity evaluation of major antioxidant phenolics in Lychee pulp.
Food chemistry, 2014Co-Authors: Ti Huihui, Mingwei Zhang, Ruifen Zhang, Zhengchen Wei, Yuanyuan Deng, Guo JinxinAbstract:Lychee pulp contains phenolic compounds that are strong antioxidants, but the identities of the major antioxidants present are unknown. In the present study, the major contributors to the antioxidant activity of fresh Lychee pulp were identified and their cellular antioxidant activities were investigated. Aqueous acetone extracts of Lychee pulp were fractionated on polyamide resin, and those fractions with the largest antioxidant and radical scavenging activities were selected using cellular antioxidant activity and oxygen radical absorbance capacity assays. Three compounds that were major contributors to the antioxidant activity in these fractions were obtained by reverse-phase preparative HPLC and identified as quercetin 3-O-rutinoside-7-O-α-L-rhamnosidase (quercetin 3-rut-7-rha), quercetin 3-O-rutinoside (rutin) and (-)-epicatechin using NMR spectroscopy, HMBC, and ESI-MS spectrometry. The concentration of quercetin 3-rut-7-rha was 17.25mg per 100g of Lychee pulp fresh weight. This is the first report of the identification and cellular antioxidant activity of quercetin 3-rut-7-rha from Lychee pulp.
Jie Zhang - One of the best experts on this subject based on the ideXlab platform.
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The effect of simulated digestion on the composition of phenolic compounds and antioxidant activities in Lychee pulp of different cultivars
International Journal of Food Science and Technology, 2019Co-Authors: Mukang Luo, Hesheng Liu, Qing-zhu Zeng, Shilun Fen, Jie ZhangAbstract:Simulated gastric fluid (SGF) and intestinal fluid (SIF) digestion were used to evaluate the effects of digestion on the composition of phenolic compounds and antioxidant capacities of the pulp of six Lychee cultivars. Caffeic acid, ferulic acid, procyanidin B2, epicatechin, A‐type procyanidin trimer, procyanidin A2, quercetin‐3‐rutinose‐7‐rhamnoside, rutin and isoquercitrin were quantified using HPLC‐DAD. Lychee pulp had high concentrations of procyanidin B2 (0.30~15.53 mg g⁻¹), procyanidin A2 (0.29~0.52 mg g⁻¹) and quercetin‐3‐rutinose‐7‐rhamnoside (0.16~0.45 mg g⁻¹). SGF and SIF Digestion, which significantly decreased the concentration of procyanidin B2, epicatechin and quercetin‐3‐rutinose‐7‐rhamnoside. But observably increased the concentration of procyanidin A2. Compared with deionized water treatment (DW), the total phenolic content (TPC) and total flavonoid content (TFC) of different Lychee pulps significantly increased after SGF and SIF digestion. After SGF digestion, the ferric ion reducing antioxidant power (FRAP) of Lychee pulps increased while the ABTS+ free radical scavenging ability (ABTS) had a slight decline. This shows that simulated digestion improves the bioactive component and antioxidant activity of different varieties of Lychee pulp.
Sang Chul Lee - One of the best experts on this subject based on the ideXlab platform.
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oligomerized Lychee fruit extract olfe and a mixture of vitamin c and vitamin e for endurance capacity in a double blind randomized controlled trial
Journal of Clinical Biochemistry and Nutrition, 2012Co-Authors: Seung Wan Kang, Seokyung Hahn, Jung Kyu Kim, Seung Min Yang, Byung Joo Park, Sang Chul LeeAbstract:Antioxidant supplementations are commonly used as an ergogenic aid for physical exercise despite its limited evidence. The study aimed to investigate the effects of a polyphenol mixture and vitamins on exercise endurance capacity. Seventy regularly exercising male participants were randomly assigned to receive oligomerized Lychee fruit extract, a mixture of vitamin C (800 mg) and E (320 IU), or a placebo for 30 consecutive days. The study results showed that oligomerized Lychee fruit extract significantly elevated the submaximal running time (p = 0.01). The adjusted mean change was 3.87 min (95% CI: 1.29, 6.46) for oligomerized Lychee fruit extract, 1.33 (−1.23, 3.89) for the vitamins, and 1.60 (−1.36, 4.56) for the placebo (p = 0.33 in between groups). Oligomerized Lychee fruit extract significantly increased the anaerobic threshold by 7.4% (1.8, 13.0). On the other hand, vitamins significantly attenuated VO2max by −3.11 ml/kg/m (−5.35, −0.87). Their effects on plasma free radical amount, however, were similar. Our results suggest that a polyphenol-containing supplement and typical antioxidants may have different mechanisms of action and that the endurance-promoting effect of oligomerized Lychee fruit extract may not directly come from the scavenging of free radicals but may be attributed to other non-antioxidant properties of polyphenols, which requires further investigation.
