Influence of Production Factors on the Physico-Chemical Characteristics of Fermented Cassava Dough and Sensory Evaluation of Attieke

Attieke is an Ivorian semolina which obtained by fermenting, pressing and steaming cassava dough. Attieke production remains a traditional activity carried out by less literate women. However, perceived differences in measurable factors and attieke qualities require an investigation of their influence on the characteristics of the pressed dough and attieke. The aim of this study is to improve the quality of the dough in relation to that of the attieke produced. The experiment was carried out on 4 production factors, namely the type of boiled or braised ferment, the incorporation rate of the ferment between 8 and 10%, the addition of oil from 0.1 to 1% and the fermentation time from 12 to 15 hours applied to the Improved African Cassava (IAC) variety. A complete experiment design of 16 samples of fermented dough and attieke was employed. These samples underwent physic-chemical analyses for the fermented dough and sensory evaluation for the attieke. It was found that, except for titratable acidity, reducing sugar content and ash content, the physico-chemical characteristics of the dough of IAC variety were significantly influenced by all production factors and their interaction. Fermentation time significantly influences 60% of the physico-chemical characteristics of the fermented dough. The type of ferment, the oil addition and the ferment rate have a significant influence at 40% of these characteristics. At the sensory level, color, acidity and grain binding with an explained variance of 34.60% were essential for the appreciation of the attieke samples. Thus, these production factors could be considered for the improvement of the fermented dough and attieke production process.

Barley Protein LFBEP-C1 from Lactiplantibacillus plantarum dy-1 Fermented Barley Extracts by Inhibiting Lipid Accumulation in a Caenorhabditis elegans Model

Objective This study aimed to investigate the lipid-lowering activity of LFBEP-C1 in high glucose-fed Caenorhabditis elegans(C.elegans).Methods In this study,the fermented barley protein LFBEP-C1 was prepared and tested for its potential anti-obesity effects on C.elegans.The worms were fed Escherichia coli OP50(E.coli OP50),glucose,and different concentrations of LFBEP-C1.Body size,lifespan,movement,triglyceride content,and gene expression were analyzed.The results were analyzed using ANOVA and Tukey's multiple comparison test.Results Compared with the model group,the head-swing frequency of C.elegans in the group of LFBEP-C1 at 20μg/mL increased by 33.88%,and the body-bending frequency increased by 27.09%.This indicated that LFBEP-C1 improved the locomotive ability of C.elegans.The average lifespan of C.elegans reached 13.55 days,and the body length and width of the C.elegans decreased after LFBEP-C1 intake.Additionally,LFBEP-C1 reduced the content of lipid accumulation and triglyceride levels.The expression levels of sbp-1,daf-2,and mdt-15 significantly decreased,while those of daf-16,tph-1,mod-1,and ser-4 significantly increased after LFBEP-C1 intake.Changes in these genes explain the signaling pathways that regulate lipid metabolism.Conclusion LFBEP-C1 significantly reduced lipid deposition in C.elegans fed a high-glucose diet and alleviated the adverse effects of a high-glucose diet on the development,lifespan,and exercise behavior of C.elegans.In addition,LFBEP-C1 regulated lipid metabolism mainly by mediating the expression of genes in the sterol regulatory element-binding protein,insulin,and 5-hydroxytryptamine signaling pathways.

Effect of fermented Rosa roxburghii Tratt fruit juice on gut microbiota in a dextran sulfate sodium-induced colitis mouse model

This study mainly investigated the regulatory effect of Rosa roxburghii Tratt fruit juice fermented by Lacticaseibacillus paracasei SR10-1(LAB-RRTJ)on modulating gut microbiota in dextran sulfate sodium(DSS)-induced ulcerative colitis in mice.Compared to control group,DSS induction decreased body weight of mice,indexes of Shannon,Simpson,Chao1 and Faith_pd,and increased disease activity index(DAI)and levels of interleukin 1β(IL-1β),IL-6,tumor necrosis factorα(TNF-α)and interferon-γ(IFN-γ);And this induction also led to an increase in Proteobacteria,Verrucomicrobia and Actinobacteria at phylum level,harmful bacterial species richness at genus level,and relative richness of S.sciuri,Desulfovibrio C21_c20,R.gnavus and Akkermansia muciniphila at species level,and a decrease in Firmicutes at phylum level and relative richness of B.acidifaciens in mice.LAB-RRTJ increased body weight of mice with DSS induced ulcerative colitis(UC)and indexes of Shannon,Simpson,Chao1 and Faith_pd,reduced DAI and the content of four infl ammatory factors and improved gut microbiota imbalance in DSS induced UC mice.Besides,the number of operational taxonomic units(OTUs)increased,α-diversity andβ-diversity were restored and similar to those in mice in the control group after LAB-RRTJ treatment.Compared with the positive drug treatment group,LAB-RRTJ has a better effect on regulating gut microbiota diversity in colitis mice.Correlation analysis showed that infl ammatory factors were positively correlated with harmful bacteria and negatively correlated with beneficial bacteria which commonly found in some colitis mice.Taken together,our study demonstrated that LAB-RRTJ could alleviate DSS-induced colitis in mice through the modulation of infl ammatory cytokines and gut microbiota composition.

Effects of probiotics and its fermented milk on constipation: a systematic review

This study reviewed clinical evidence of probiotics-mediated effects on constipation.Four databases were used in the literature searches,namely Cochrane Library,Embase,Pubmed,and Web of Science.The last retrieval time was March 2021.Collected data were analyzed by Review Manager(version 5.3)and Stata(version 14).The primary search retrieved 8418 articles after removing duplicates.Eventually,26 studies were included in the meta-analysis.Administration of probiotics signifi cantly increased stool frequency(MD:1.15 times/week;95%CI:0.59 to 1.70;P<0.0001),improved bloating(MD:-0.48;95%CI:-0.89 to-0.07;P=0.02),reduced abdominal pain(MD:-0.71;95%CI:-1.25 to-0.16;P=0.01),and improved quality of life(MD:-0.73;95%CI:-1.37 to-0.10;P=0.02).However,the clinical effect of intake of probiotics on stool consistency was non-signifi cant(MD:0.07;95%CI:-0.34 to 0.48;P=0.73).Based on our analysis,probiotic supplements were effective in relieving constipation through symptom improvement.The effectiveness of dosage forms of intervention ranked:capsules>others(tablets,powder)>fermented milk.

Selected fermented indigenous vegetables and fruits from Malaysia as potential sources of natural probiotics for improving gut health

In the Peninsular Malaysia and Northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water contents, thus, naturally vulnerable to rapid food spoilage. Food preservation and processing play a vital role in the inhibition of food pathogens in fruits and vegetables that are prevalent in Malaysia. Lactic acid fermentation is generally a local-based bioprocess, among the oldest form and well-known for food-processing techniques among indigenous people there. The long shelf life of fermented vegetables and fruits improves their nutritional values and antioxidant potentials. Fermented leaves and vegetables can be utilized as a potential source of probiotics as they are host for several lactic acid bacteria such as Lactobacillus confusus, Weissella paramesenteroides, Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus pentosus, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides. These strains may be more viable in metabolic systems whereby they can contribute to a substantial increase in essential biologically active element than industrial starter cultures. This review is aimed to address some essential fermented fruits and vegetables in Malaysia and their remarkable reputations as a potential sources of natural probiotics.

Roles of fermented plant-,dairy-and meat-based foods in the modulation of allergic responses

This review attempts to delineate the effects and roles of fermented foods on allergic responses(AR),specifically from milk,plant,and meat sources.Evidence for AR alleviation and aggravation were noted for many different fermented food groups.Positive outcomes on AR through fermented foods could be linked to microbial hydrolysis of food allergens,improvement in gut microbiota robustness,and modulation of the immune system that promotes a balance between T helper 1(Th1)and Th2 cells.Studies on plant-based,non-protein rich fermented foods tend to show more favourable results compared to those on meat-based or protein-rich group.The usage of specific and known starter cultures are helpful in alleviating AR,as in the case for many yogurt,Kefir or Dahi products.Sufficient fermentation time was also deemed important,exemplified in studies that showed inefficient AR reduction through consumption of fresh cheese.However,formation of new allergens through fermentation of certain meat-based foods,or by using specific fermenting microbes(e.g.Penicillium sp.),is possible.Thus,combination of starter cultures and food substrates must be considered in preventing or eliminating AR from intake of these foods.This review may aid consumers to make informed decision during the consumption of fermented food.

Effect of inoculating mixed starter cultures of Lactobacillus and Staphylococcus on bacterial communities and volatile flavor in fermented sausages

The objective of this study was to explore the effects of the inoculation of mixed starter cultures of Lactobacillus and Staphylococcus(labeled L-S)on microbial community and flavor in fermented sausages during the ripening process.Culture-dependent(colony count)and culture-independent(high-throughput sequencing)methods were employed to evaluate bacterial communities.Volatile compounds were identified by gas chromatography-mass spectrometry,and the results were analyzed by principal component analysis(PCA).The identified bacteria with high relative abundance included Lactobacillus and Pediococcus,and the relative abundances of Leuconostoc and Weissella in fermented sausages were remarkably decreased at the end of the ripening process.At the end of ripening,2-nonenal,tetradecanal,ethylstearate and terpinyl acetate played substantial roles in the flavor development of the L-S fermented sausages.Sensory evaluation showed a high score in the L-S fermented sausages.Sausages can be inoculated with L-S starter culture to improve the safety and flavor of meat products.

Comparative effects of soy protein concentrate,enzyme‑treated soybean meal,and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

Insights into microbiota community dynamics and flavor development mechanism during golden pomfret(Trachinotus ovatus)fermentation based on single-molecule real-time sequencing and molecular networking analysis

Popular fermented golden pomfret(Trachinotus ovatus)is prepared via spontaneous fermentation;however,the mechanisms underlying the regulation of its flavor development remain unclear.This study shows the roles of the complex microbiota and the dynamic changes in microbial community and flavor compounds during fish fermentation.Single-molecule real-time sequencing and molecular networking analysis revealed the correlations among different microbial genera and the relationships between microbial taxa and volatile compounds.Mechanisms underlying flavor development were also elucidated via KEGG based functional annotations.Clostridium,Shewanella,and Staphylococcus were the dominant microbial genera.Forty-nine volatile compounds were detected in the fermented fish samples,with thirteen identified as characteristic volatile compounds(ROAV>1).Volatile profiles resulted from the interactions among the microorganisms and derived enzymes,with the main metabolic pathways being amino acid biosynthesis/metabolism,carbon metabolism,and glycolysis/gluconeogenesis.This study demonstrated the approaches for distinguishing key microbiota associated with volatile compounds and monitoring the industrial production of high-quality fermented fish products.

Detection, Biochemical and Molecular Characterization of Clostridium sporogens in Nono: A Nigerian Traditionally Fermented Yoghurt Drink

Nono is a traditionally fermented milk drink commonly consumed in the Northern parts of Nigeria. It is produced through the spontaneous fermentation of raw cow milk by Lactic Acid Bacteria (LAB), a process that could result to the contamination of the product with such pathogenic organisms as Clostridia spp. The aim of this research was therefore to determine the incidence of Clostridia species in thirty-two (32) ready-to-drink nono samples collected directly from a number of Fulani vendors in randomly selected locations within the Federal Capital Territory (FCT), Abuja, Nigeria. Isolated organisms were further subjected to some morphological and biochemical characterizations using standard microbiological procedures. The results obtained indicate that fourteen (14) isolates were putatively identified to be Clostridium sp., out of which five (5) isolates were confirmed to be Clostridium sporogens by a BLAST analysis of their respective 16SrRNA nucleotide sequence. It was concluded that, the detection of these pathogenic strains in frequently consumed product like nono could pose a public health risk and proactive measures to prevent an outbreak of food borne illness from nono consumption, were recommended.

Biotechnology of Okpeye: A Nigerian Traditional Fermented Food Condiment

Most legumes and oil bean seeds used in condiment manufacture in Africa are inedible by nature. They contain antinutritional elements such indigestible oligosaccharides and phytate. Fermentation affects desired alterations by lowering anti-nutritional components and enhancing digestibility. Okpeye is a traditional West African seasoning prepared from Prosopis africana seed solid substrate fermentation. Many homes consider it as a family business because the preparation follows a passed-down habit from previous generations as an inexpensive source of plant protein. However, natural nature of the fermentation process raises concerns about the consistency, quality, and safety of the finished product. Because the seasoning is created on a small scale with less sophisticated equipment and manufacturing procedures, there are concerns about microbial safety. Thus, fermentation process and the range of microbial composition involved in Prosopis africana okpeye production were evaluated in this review. Potential spoilage agents, as well as biochemical and nutritional changes occurring during production of okpeye are gaining interest among researcher. This review highlights information that can help in developing starter cultures in a controlled fermentation process that ensures quality, longer shelf life, and microbiological safety.

Structure and immunomodulatory activity of Lentinus edodes polysaccharides modified by probiotic fermentation

Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.

Beneficial effects of fermented jujube pulp in relieving loperamide hydrochloride-induced constipation in male ICR mice

Unfermented jujube pulp(UFJP),fermented jujube pulp(FJP)in high and low doses were fed to constipated ICR mice.Defecation function,serum gastrointestinal regulatory peptide,fecal short-chain fatty acids(SCFAs)and gut microbial composition were assessed.Results showed that high-dose FJP could protect intestinal mucosa tissue,shorten the first black feces defecating time by 17%and increase the number and wet weights of black feces by 72%and 71%,respectively,within 6 h.High-dose FJP signifi cantly down-regulated the somatostatin level and up-regulated gastrin level in constipated mice,compared with low-dose FJP and UFJP.The high-dose FJP intervention regulated the microbiota profi le,which afterwards restored microbiota,like Bacteroidetes,Bifi dobacterium and Lactobacillus,to a less unhealthy state.This study provides convincing in vivo evidence that high-dose FJP supplementation through daily diet could be a promising approach to effectively alleviate constipation and modulate gut health.

Influence of nitrogen status on fermentation performances of non-Saccharomyces yeasts:a review

Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances including the formation of secondary metabolites.Saccharomyces cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen impacts.On the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being reported.This review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent studies.Detailed discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final section.In summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile production.Research gaps will therefore be elucidated for future research.

Characterization and discrimination of fermented sweet melon juice by different microbial strains via GC-IMS-based volatile profiling and chemometrics

The main purpose of this study was to investigate the effect of different lactic acid bacteria and yeast strains on the volatile composition of fermented sweet melon juice.Headspace gas chromatography-ion mobility spectrometry(HS-GC-IMS)coupled with chemometrics was performed to identify the potential volatiles for the discrimination of different fermented sweet melon juice.In total,70 volatile compounds were found in the fermented sweet melon juices.Of them,45 compounds were annotated according to the GC-IMS database and classified into esters,alcohols,aldehydes,ketones and furans.Results from the multivariate analysis reveal that sweet melon juice fermented by different combinations of microbial strains could be distinctly separated from each other.A total of 15 volatiles with both variable importance in projection value>1 and P<0.05 were determined as potential markers for the discrimination of fermented sweet melon juice.This study confirms the effect of microorganisms on the flavor of the fermented sweet melon juice and shows the potential of HS-GC-IMS combined with chemometrics as a powerful strategy to obtain volatile fingerprints of different fermented sweet melon juice.

Correlation of Microbiological Stability with Redox Processes in White Wines

In this paper, the authors analyzed the correlation between the microbiological stability of white wines and the content of sulfur dioxide, which influences the main redox processes that take place in the technological stages of the wine. The consecutive, parallel and spontaneous development of several redox processes and their impact on the quality, microbiological and crystalline stability of white wines were examined. The reduction of additive and subtractive technological interventions, of the amounts of adjuvants (sulphurous anhydride) is essential for the production of organic wines.

The Advantages of Methane Production by Combined Fermentation of Lignite and Wheat Straw

Biogasification of coal is important for clean utilization of coal. Experiments on the fermentation of single lignite, single straw and their mixture were performed to explore the variation characteristics of gas production potential, microbial community and methanogenic metabolic pathways of mixture. Research has shown that mixed fermentation of lignite and straw significantly promoted biomethane production. The abundance of hydrolytic acidifying functional bacteria genera (Sphaerochaeta, Lentimicrobium) in mixed fermentation was higher than that in the fermentation of single lignite and single straw. The abundance of some key CAZy metabolic enzyme gene sequences in mixed fermentation group was increased, which was favorable to improve methane production. Aceticlastic methanogenesis was the most critical methanogenic pathway and acetic acid pathway was more competitive in methanogenic mode during peak fermentation. Macrogenomics provided theoretical support for the claim that mixed fermentation of coal and straw promoted biomethane metabolism, which was potentially valuable in expanding methanogenesis from mixed fermentation of lignite with different biomasses.

Isolation, Characterisation and Evaluation of Antiulcerogenic Potentials of Probiotic Lactic Acid Bacteria Isolated from Fermented Milk and Palm Wine against Ethanol-Induced Gastric Ulcer in Mice

Background: Gastric ulcer is one of the most common gastrointestinal diseases with a worldwide prevalence of about 40% in the developed countries and 80% in Africa. Acid inhibitors, anticholinergics, histamine H2-antagonists and antibiotics are commonly used to treat gastric ulcer. However, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors, anticholinergics and histamine H2-antagonists. Therefore, there is an urgent need for approaches to treat and prevent gastric ulcer. One alternative strategy is the use of probiotic lactic acid bacteria. Aim of the study: This study aimed to isolate and characterised probiotic lactic acid bacteria from palm wine and fermented milk, and to evaluate their antiulcerogenic potentials on ethanol-induced gastric ulcer in mice. Methods: Probiotic lactic acid bacteria were isolated from the fermented milk and palm wine using pour plate technique on MRS agar and identified using the 16S r RNA gene sequencing. For functional properties and selection, acid and bile salt tolerance were evaluated based on viable colony count on MRS agar. Two probiotic lactic acid bacteria were selected for in vivo studies. Fifty-four healthy young adult Balb/c mice were randomly divided into 9 groups of 6 mice each. Gastric ulcer was induced in mice using one oral dose of absolute ethanol (10 mL/kg body weight). The probiotic lactic acid bacteria (F1 and F2) at different doses (MF3 = 9 × 108 CFU/mL, MF6 = 1.8 × 109 CFU/mL and MF9 = 2.7 × 109 CFU/mL) and omeprazole (20 mg/kg) (a reference drug) were orally administrated daily for 14 days before ulcer induction. These mice were sacrificed 1hour after induction and the stomach contents were collected for volume and pH determination. The stomachs were subjected to macroscopic, biochemical and histopathological analysis. Results: Among the isolates obtained, two were considered to have the best acid and bile tolerance capacity (viable count > 7.5 logCFU/ml) and were identified as Limosilactobacillus fermentum strain BB101 (F1) and Lactobacillus casei strain 02 (F2). Oral administration of probiotics Lactic acid bacteria F1 and F2 significantly attenuated gastric ulcer as revealed by significant reduction (P Conclusion: The results of this study revealed that palm wine and fermented milk are sources of potential probiotic lactic acid bacteria, that is lactobacillus fermentum strain BB101 and Lactobacillus casei 02 with excellent bile and acid tolerance capacity. Also, these probiotic lactic acid bacteria exhibit gastroprotective effect on ethanol-induced gastric ulcer via antioxidant, enhance gastric ulcer healing, antacids, and anti-secretary effects.

Modifications in aroma characteristics of'Merlot'dry red wines aged in American,French and Slovakian oak barrels with different toasting degrees

Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.

The protective effect of cyclodextrin on the color quality and stability of Cabernet Sauvignon red wine

The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.