Pleasant Flavor Research Articles

Genome-Wide Association Studies of Biluochun Tea Plant Populations in Dongting Mountain and Comprehensive Identification of Candidate Genes Associated with Core Agronomic Traits by Four Analysis Models.

The elite germplasm resources are key to the beautiful appearance and pleasant flavor of Biluochun tea. We collected and measured the agronomic traits of 95 tea plants to reveal the trait diversity and breeding value of Biluochun tea plant populations. The results revealed that the agronomic traits of Biluochun tea plant populations were diverse and had high breeding value. Additionally, we resequenced these tea plant populations to reveal genetic diversity, population structure, and selection pressure. The Biluochun tea plant populations contained two groups and were least affected by natural selection based on the results of population structure and selection pressure. More importantly, four non-synonymous single nucleotide polymorphisms (nsSNPs) and candidate genes associated with (-)-gallocatechin gallate (GCG), (-)-gallocatechin (GC), and caffeine (CAF) were detected using at least two GWAS models. The results will promote the development and application of molecular markers and the utilization of elite germplasm from Biluochun populations.

Effects of Xanthan gum and Potassium carbonate on the quality and flavor properties of frozen Jiuniang doughs

Chinese Jiuniang (CJ) is a flavorful and nutritious food, but underutilized in frozen dough (FD) production. In addition, frozen storage can harm FD's gluten structure and degrade quality and flavor. Therefore, the impacts of two excellent protective agents (XG-Xanthan Gum; PC-Potassium Carbonate) on frozen Jiuniang dough (F-JD) quality and flavor during dynamic freezing were investigated. The results suggested that adding XG conferred F-JD with good processing stability, maintained the bound water levels, stabilized rheological properties, diminished ice crystal damage to the protein structure, and inhibited the increase in frozen water content during the freezing process. In contrast, although PC reduced free water production during freezing, it increased dough hardness and offered less protein protection than XG. Additionally, GC-QTOF/MS analysis showed that adding XG during freezing increased the relative content of pleasant flavor compounds like Phenylethyl Alcohol and decreased undesirable ones like Hexanal. Moreover, PC lowered the relative content of undesirable flavor substances (Formic acid) but reduced the relative content of beneficial flavor compounds (1-Hexanol). Importantly, the study confirmed that XG maintained the new F-JD product's storage quality during dynamic freezing. In conclusion, this study broadens CJ's application possibilities and provides new insights into mechanisms for preserving F-JD's quality and flavor.

Effect of tea-polyphenol/β-cyclodextrin/NaCl inclusion complexes as a salt substitute on quality of low-salt Sichuan-style sausages

An abundance of low-salt sausages had emerged in the market as high salt intake may pose health risks to humans while their limited shelf-life becomes an urgent issue. In this study, tea-polyphenol/β-cyclodextrin/NaCl inclusion complexes (ICs) with thermal stability and better antioxidant activity were successfully prepared, their effects on the quality of low-salt sausages were investigated. The sausages were manufactured with the addition of ICs and NaCl with or without tea-polyphenols respectively, and they were stored at 25 °C for 28 days. IC group exhibited significantly lower oxidation of lipids and protein as the tea-polyphenols in the ICs could exert better antioxidant properties because of the special encapsulation structure. Besides, ICs could inhibit the growth of pathogens preventing the off-flavor. Also, ICs promoted the growth of P. pentosaceus with a strong antioxidant capacity in the sausage model, which maintained the existing pleasant flavor by preventing the oxidation of phenol and alcohol compounds. Meanwhile, ICs also accelerated the growth of Tetragenococcus, which contributed to flavor development at the later stages of fermentation by producing more esters. Hence, it was suggested that ICs could be utilized as a promising salt replacement to improve the quality of traditional Sichuan-style sausages.

Kaili Red sour soup: Correlations in composition/microbial metabolism and flavor profile during post-fermentation

Flavor and chemical changes with microbial succession during Red-Sour-Soup (RSS) post-fermentation were urgent to be revealed for quality control. RSS post-fermentation could be divided into three stages according to acidity, nutrients exhausting and total colony counts, without coliform bacteria growth nor nitrite peak was observed. Lactobacillus acetotolerans induced over 50 % increase of lactic acid, finally conducing to the lactic acid-dominated sour taste of RSS. The volatile compounds totally increased by 25.70 % in chili sauce and 32.58 % in tomato sauce (p < 0.05). In early-/middle-stage (pH > 3.5), alcohols and short-chain fatty acids increased, and butyric acid with unpleasant odor became the maximum flavor contributor. Nevertheless, in late-stage (pH < 3.5), with the reduction of alcohols and fatty acids, esters, 2-nonanone and terpenoids with pleasant flavors increased by Clavispora lusitaniae, Pichia, Cladosporium delicatulum and Rozellomycota sp.. In conclusion, the post-fermentation, especially L. acetotolerans metabolism and aciduric fungal esterification were essential for RSS characteristic flavor formation.

Influences of Lactiplantibacillus plantarum and Saccharomyces cerevisiae fermentation on the nutritional components, flavor property and lipid-lowering effect of highland barley

Highland barley is a well-known cereal in Qinghai-Tibet Plateau area with high nutritional value, which has been reported to be a health-promoting grain for the obesity and the diabetes. Fermentation by certain microbiota can improve the flavor property and nutritional characteristics. In the present study, Lactiplantibacillus plantarum and Saccharomyces cerevisiae were singly or jointly applied to ferment highland barley, and the profile of volatile substances and lipid-lowering effects of the respective extracts were analyzed. Results indicated that either L. plantarum or S. cerevisiae or co-fermentation could consume the polysaccharides of highland barley to provide energy, and dramatically increase the contents of total protein and polyphenol. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the presence of S. cerevisiae was critical for production of the pleasant flavors, especially for the ethyl ester substances including hexadecanoic acid ethyl, hexanoic acid ethyl ester and so on. Meanwhile, we found that fermented highland barley extracts by L. plantarum exhibited stronger lipid-lowering effects in Caenorhabditis elegans than that by S. cerevisiae, while the co-fermentation not only emitted pleasant odors but also exerted high hypolipidemic function. In all, co-fermentation by L. plantarum and S. cerevisiae was proposed to be a promising processing to improve the flavor and functional properties of highland barley.

First report of Colletotrichum siamense causing grape ripe rot in Brazil.

Vitis vinifera cv. BRS Vitória is a seedless black table grape cultivar with an extremely pleasant flavor and is adapted to cultivation in all Brazilian regions. Between November and December 2021, grape berries presenting typical ripe rot symptoms were found in three vineyards located in Petrolina, Pernambuco Brazil. The first symptoms are small and depressed lesions on ripe berries, presenting tiny black acervuli. As the disease progress, lesions enlarge and affect the whole fruit, and abundant orange masses of conidia can be observed. Finally, berries become completely mummified. Symptoms were observed in the three vineyards visited, and disease incidence was above 90%. Some producers are considering eradicating the plantations due to the losses caused by the disease. Control measures used so far are costly and ineffective. Fungal isolation was performed by transferring conidial masses from 10 diseased fruit to plates containing potato dextrose agar medium. Cultures were incubated at 25 °C under continuous light. Seven days after inoculation, three fungal isolates (LM1543-1545) were obtained and subcultivated in pure culture for species identification and pathogenicity test. Isolates presented white to grey cottony mycelia, and hyaline conidia with cylindrical with rounded ends, which resemble the genus Colletotrichum (Sutton 1980). Partial sequences of APN2-MAT/IGS, CAL, and GAPDH loci were amplified, sequenced, and deposited on GenBank (OP643865-OP643872). Isolates from V. vinifera were placed within the clade including the ex-type and representative isolates of C. siamense. The clade was strongly supported (99.8% bootstrap support) in the maximum likelihood multilocus tree of the three loci combined, which confidently assign the isolates to this species. Inoculation on grape bunches was performed to confirm pathogenicity. Grape bunches were surface sterilized for 30 s in 70% ethanol, 1 min in 1.5% NaOCl, rinsed two times with sterile distilled water, and air-dried. Fungal conidial suspensions (106 conidia mL-1) were sprayed to the point of run-off. The negative control was represented by grape bunches sprayed with sterile distilled water. Grape bunches were kept in a humid chamber for 48 h at 25 °C and a light period of 12 h. The experiment was conducted with four replicates (four inoculated bunches per isolate) and repeated once. Typical ripe rot symptoms were observed on grape berries 7 days after inoculation. No symptoms were observed on the negative control. The fungal isolates recovered from inoculated berries were morphologically identical to the C. siamense isolates originally recovered from symptomatic berries collected in the field, fulfilling Koch's postulates. Colletotrichum siamense was reported in association with grape leaves in USA (Weir et al. 2012) and causing grape ripe rot in North America (Cosseboom & Hu 2022). Only C. fructicola, C. kahawae, C. karsti, C. limetticola, C. nymphaeae and C. viniferum were reported causing grape ripe rot in Brazil (Echeverrigaray et al. 2020). To our knowledge, this is the first report of C. siamense causing grape ripe rot in Brazil. This finding is important for disease management because C. siamense has a high phytopathogenic potential due to its wide distribution and host range.

Investigating flavor sensory properties of Zhenjiang aromatic vinegar and factors impacting perception using quantitative descriptive analysis and temporal dominance of sensations

AbstractThe aim of this study was to make a sensory scientific and chemical characterization of flavor profiles of Zhenjiang aromatic vinegar (ZAV) from different grades, and to investigate their potential correlation for evaluating the effects of chemical components on sensory perception. The quantitative descriptive analysis (QDA) was combined with temporal dominance of sensations (TDS) to assess the sensory properties of different grades of ZAV. The grades of ZAV were best differentiated by pungent (p &lt; .001), almond (p &lt; .001), burnt (p &lt; .001), sour (p &lt; .001), bitter (p &lt; .001), and salty perception (p &lt; .001). TDS showed ZAV of five grades differed in the combination of dominant sensory attributes. Both QDA and TDS differentiated the ZAV samples of different grades. Multiple factor analysis (MFA) of QDA, aroma, and physicochemical data showed these data set were well correlated, which contributed to the identification the chemical drivers of sensory attributes.Practical ApplicationsZhenjiang aromatic vinegar (ZAV) is a highly appreciated product all over the world due to its unique and pleasant flavor sensory properties. The combined use of QDA and TDS permitted the identification and quantitative description of flavor profiles for ZAV from different grades while providing additional information during the consumption of ZAV, which has proved to be more beneficial than each just on its own. In addition, the key flavor substances that influence the sensory attributes were found out by analyzing the variables correlations and product spaces though MFA, thus it is help to strengthen the flavor quality control in the ZAV products. Taken overall, this work provides a reference for the measurement of flavor profiles of ZAV related products and evaluation the internal chemical components affecting sensory attributes.

Detection of counterfeit sesame oil based on Raman spectroscopy and chemometric analysis

Sesame oil is popular in China and many other Asian countries due to its pleasant flavor and high nutritional value. Sesame oil essence is often illegally added to other vegetable oils to counterfeit sesame oil. This study aimed to propose a rapid and cost-effective method, which could help to identify the sesame oil and counterfeit sesame oil. For this purpose, the counterfeit samples were prepared by adding essence to inferior oils (soybean oil, sunflower oil, canola oil, corn oil), all oil samples were examined and their Raman spectra served as data for the construction of the soft independent modeling of class analogy (SIMCA) models and the important variables for distinguishing between authentic and counterfeit sesame oil were selected by orthogonal partial least squares discriminant analysis. The results showed that SIMCA is a strong chemometric technique for classification of authentic sesame oils and the types of counterfeit sesame oil samples based on Raman spectra, and a total 100% correct classification rate of sesame oil could be achieved. The methods allowed the identified counterfeit sesame oil in commercial sesame oil samples, opening the door to further research into the counterfeit detection of other liquid foods.

Impact of seed-roasting treatment on polycyclic aromatic hydrocarbons, 3-MCPD esters, heterocyclic amines and volatile components formation in sunflower oil

Seed-roasting is a crucial process conducted to improve the organoleptic and conservative features of oilseeds. In this paper, raw sunflower seeds were roasted at 160, 180 and 200 °C for various times. Three hazards (polycyclic aromatic hydrocarbons, 3-monochloro-1,2-propanediol esters and heterocyclic amines) and volatile components in the corresponding oil extracted from roasted sunflower seeds were analyzed. Polycyclic aromatic hydrocarbons, 3-monochloro-1,2-propanediol esters and heterocyclic amines were measured using HPLC, GC-MS and UPLC-MS, respectively. Volatiles were determined by GC-MS. The results show that the strength of seed-roasting promoted the formation of the three hazard factors. The contents of polycyclic aromatic hydrocarbons, 3-monochloro-1,2-propanediol esters and heterocyclic amines in sunflower oil increased 9.4, 22.1 and 121.6 fold respectively after roasting at 200 °C for 25 min. The main volatiles were aldehydes and terpenes with a greenish and earthy taste. Volatile levels possessing pleasant flavors of floral, roasted and nuts, particularly aldehydes and pyrazines, generally increased with roasting. However, at high intensity roasting, the appearance of furans would bring burnt, bitter, as well as viscosity, resulting in poor sensory for oil. Considering the limitation of the above mentioned hazards established by EU, the optimal roasting condition of sunflower seed was 180–200 °C for 15–20 min.

Firstreportflat peach fruit rotcausedbyFusariumfujikuroi in China.

Flat peach (Prunus persica L. Batsch. var. compressa Bean) is a distinctive peach variety with flat shape. It is well known for its high nutritional value and pleasant flavor, and has become the primary cultivar in Shengzhou city, Zhejiang province, China. In July 2021, we discovered that 8%-10% of flat peach (data gained from a survey of fifteen trees in each orchard) fruits in three orchards (about 2.6 ha) had a fungal disease in Jinting Town, Shengzhou. The infected fruit by this pathogen showed soft, brown, and sunken lesions, accompanied by a sour odor and white mycelia. For pathogen isolation, ten infected fruits were surface sterilized (75% ethanol for 30 s and 2.0% NaClO for 3 min), then rinsed with sterile distilled water three times. The tissues from the margin of lesions were cut into 0.6×0.6 cm pieces and transferred to potato dextrose agar (PDA) medium containing 30.0 μg/mL chloramphenicol. The plates were incubated at 25 °C for 5 days in the dark. Mycelia growing from tissues were subcultured onto fresh PDA medium to get a pure isolate, which formed dense white hyphae after 4 days. The average growth rate of mycelium on PDA medium was 3.4 ± 0.2 mm/d, and the colonies were pale purple after 5 days. Macroconidia was slender, slightly curved, almost 2 to 3 septa, with a bend and tapering apical cell and poorly developed foot cell, and the size was 4.5 to 16.9 × 1.8 to 4.0 μm (n= 50) μm. No microconidia and chlamydospores were observed. This isolate's morphological and cultural characteristics were close toFusarium fujikuroi(Leslie and Summerell. 2006). To further get the phylogenetic evidence, the nuclear ribosomal internal transcribed spacer region (ITS) and translation elongation factor-1 (TEF-1α) genes of three representative isolations were amplified by primers ITS1 (F:5'-GGAAGTAAAAGTCGTAACAAGG-3') /ITS4 (R5'-TCCTCCGCTTATTGATATGC-3') (Groenewald et al. 2013), and EF1-728F (5'-TACAARTGYGGTGGTATYGACA-3')/ EF1-986R (5'-ACNGACTTGACYTCAGTRGT-3') (Carbone and Kohn. 1999), respectively. The amplified sequences were submitted to Genbank with accession numbers OP223318 for the IST and OP394152 for the ETF-1α region. Blastn results indicated that the ITS and TEF-1α sequences from the isolated strain shared 96.25% and 98.32% similarity with two strains of F.fujikuroi (GenBank Accession No. MF281286.2, and MK311296.1). The isolates were clustered with F.fujikuroi clade (Supplementary Fig.1 and Supplementary Fig.2), consistent with the morphological identification. To evaluate Koch's postulates, 20μL of spore suspension (1×106 spores/mL) were inoculated into ten healthy flat peach fruits with sterile syringes, while another ten healthy fruits were injected with sterilized water as controls. All fruits were kept in sealed plastic boxes at 25 °C with 90% relative humidity. All inoculated fruits showed symptoms similar to those of naturally infected fruits, while uninoculated fruits remained healthy after 4 days. In addition, F. fujikuroi was an important pathogen causing bakanae disease in rice (Hou et al. 2017). This pathogen was also reported to cause Lilium lacifolium Thunb bulb rot (Fang et al. 2022) and cause root rot in peanuts in China (Sun et al. 2022). However, to the best of our knowledge, this is the first record of F. fujikuroi causing fruit rot in flat peach in China. The discovery will provide helpful information about flat peach rot disease management.

Effect of cooking methods on volatile compounds and texture properties in rice porridge

Rice porridge is known to be pleasant flavor and health-beneficial. This study investigated the effect of cooking time and methods on the flavor and texture of rice porridge. The volatile compounds of rice porridge were extracted using headspace-solid phase micro extraction and analyzed by gas chromatography-mass spectrometry. A total of 110 volatiles were detected in rice porridge. Except for esters, most other volatile compounds decreased with cooking time. The major volatiles, aldehydes, and esters have a relatively high content in electric rice cooker (IC). The flavor of rice porridge shifted from grass to ester with cooking time. Multiple chemometrics revealed that volatile compounds with different cooking methods were scattered separately. Texture analysis revealed that rice porridge prepared in the electric pressure cooker (EPC) had a more significant decrease trend in hardness than electromagnetic oven (EC) and IC before 40 min. In vitro starch digestibility analysis, regardless of treatments, the rice porridge was mainly composed of fast digestible starch. The amount of fast digestible starch showed an increasing trend over time. To summarize, different cooking methods had a more significant influence on the volatile compounds than cooking time, while the texture is opposite. This study can guide rice porridge production.

Multiple-statistical genome-wide association analysis and genomic prediction of fruit aroma and agronomic traits in peaches.

'Chinese Cling' is an important founder in peach breeding history due to the pleasant flavor. Genome-wide association studies (GWAS) combined with genomic selection are promising tools in fruit tree breeding, as there is a considerable time lapse between crossing and release of a cultivar. In this study, 242 peaches from Shanghai germplasm were genotyped with 145 456 single-nucleotide polymorphisms (SNPs). The six agronomic traits of fruit flesh color, fruit shape, fruit hairiness, flower type, pollen sterility, and soluble solids content, along with 14 key volatile odor compounds (VOCs), were recorded for multiple-statistical GWAS. Except the reported candidate genes, six novel genes were identified as associated with these traits. Thirty-nine significant SNPs were associated with eight VOCs. The putative candidate genes were confirmed for VOCs by RNA-seq, including three genes in the biosynthesis pathway found to be associated with linalool, soluble solids content, and cis-3-hexenyl acetate. Multiple-trait genomic prediction enhanced the predictive ability for γ-decalactone to 0.7415 compared with the single-trait model value of 0.1017. One PTS1-SSR marker was designed to predict the linalool content, and the favorable genotype 187/187 was confirmed, mainly existing in the 'Shanghai Shuimi' landrace. Overall, our findings will be helpful in determining peach accessions with the ideal phenotype and show the potential of multiple-trait genomic prediction to improve accuracy for highly correlated genetic traits. The diagnostic marker will be valuable for the breeder to bridge the gap between quantitative trait loci and marker-assisted selection for developing strong-aroma cultivars.

Integrated Postharvest of Pitahaya fruits (Hylocereus ocamponis) stored at different temperaturs

Pitahaya (Hylocereus spp.) has been placed successfully in the global fruit market due to its exotic appearance and pleasant flavor; however, its short postharvest life has limited its marketing in national and international markets. The postharvest life and final quality of fruits depend on the state of maturity in which the fruit is harvested, as well on the storage conditions. The aim of this study was to assess the postharvest behavior of pitahaya fruits (H. ocamponis) harvested during two states of maturity (pre-consumer and consumption maturity), stored at 6 ± 1°C and 22 ± 3 °C for 24 days. The color, firmness, epicarp thickness, weight loss, soluble solids, total soluble sugars, betalains, phenolic compounds and antioxidant activity showed significant changes during the storage period. The preserved fruits at room temperature maintained their firmness and color of the epicarp, content of soluble solids, soluble sugars and betalains during 9 days of storage, but from the 16th day, they showed rottenness and degradation of epicarp betalains. In contrast, the stored fruits in refrigeration presented a lower weight loss, greater firmness, and epicarp thickness, reaching 24 days of shelf life. The antioxidant activity was greater in the pulp of the stored fruits at 22 °C, due to an apparent higher betalains concentration associated with greater water loss in the fruit.

Underutilized Fig (Ficus carica L.) Cultivars from Puglia Region, Southeastern Italy, for an Innovative Product: Dried Fig Disks

Fig fruits have recently received more attention by consumers for their quality as either fresh or dried fruits and, consequently, growers are becoming more interested in the cultivation of this species. Figs are mainly consumed as processed fruits (dried, marmalade, jam, etc.), but limited attention has been paid to new possible processing applications of several local cultivars grown in Mediterranean countries. This study aimed to investigate both the morpho-pomological characteristics and consumer sensory ratings (two groups: students and technicians) for four fig cultivars processed as a new type of product, ‘dried fig disks’. The results showed that three out of the four cultivars (Processotto Nero, Natalese Nera, and Verde di Natale) had good pomological characteristics such as fruit weight and skin color, as well as easy peeling, yield, ripening time, and TSS. The same cultivars received positive hedonic scores for appearance (&gt;5 on a 10-point hedonic scale), flavor (4–6 on a 10-point hedonic scale) and taste (6–7 on a 10-point hedonic scale). The overall score was positive for Processotto Nero, Natalese Nera, and Verde di Natale (&gt;5 on a 10-point hedonic scale), whereas one cultivar, Comunione, was less appreciated (&lt;5 on a 10-point hedonic scale). The flavor–sensory attributes most appreciated were black-red fruit, cooked, grassy, and floral; fig off-flavors were perceived as rancid only by students and to a limited extent. Consumer overall acceptance toward dried fig disks was mainly driven by the acceptability of appearance of the new product, together with pleasant flavor and taste.

Regulation of 2-acetyl-1-pyrroline and grain quality in early-season indica fragrant rice by nitrogen and silicon fertilization under different plantation methods

Fragrant rice has a high market value, and it is a popular rice type among consumers owing to its pleasant flavor. Plantation methods, nitrogen (N) fertilizers, and silicon (Si) fertilizers can affect the grain yield and fragrance of fragrant rice. However, the core commercial rice production attributes, namely the head rice yield (HRY) and 2-acetyl-1-pyrroline (2-AP) content of fragrant rice, under various nitrogen and silicon (N-Si) fertilization levels and different plantation methods remain unknown. The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars (Yuxiangyouzhan and Xiangyaxiangzhan). They were grown under six N-Si fertilization treatments (combinations of two levels of Si fertilizer, 0 kg Si ha−1 (Si0) and 150 kg Si ha−1 (Si1), and three levels of N fertilizer, 0 kg N ha−1 (N0), 150 kg N ha−1 (N1), and 220 kg N ha−1 (N2)) and three plantation methods (artificial transplanting (AT), mechanical transplanting (MT), and mechanical direct-seeding (MD)). The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars. Compared with the Si0N0 treatment, the N-Si fertilization treatments resulted in higher HRY and 2-AP contents. The rates of brown rice, milled rice, head rice, and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments. The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice, and affected their antioxidant response parameters. The key parameters for the HRY and 2-AP content were assessed by redundancy analysis. Furthermore, the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity, N use efficiency, and grain quality of fragrant rice. Moreover, high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis. The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content, whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.

Simultaneous Preparation of Chitin and Flavor Protein Hydrolysates from the By-Products of Shrimp Processing by One-Step Fermentation with Lactobacillus fermuntum.

One-step fermentation, inoculated with Lactobacillus fermentum (L. fermentum) in shrimp by-products, was carried out to obtain chitin and flavor protein hydrolysates at the same time. The fermentation conditions were optimized using response surface methodology, resulting in chitin with a demineralization rate of 89.48%, a deproteinization rate of 85.11%, and a chitin yield of 16.3%. The surface of chitin after fermentation was shown to be not dense, and there were a lot of pores. According to Fourier transform infrared spectroscopy and X-ray diffraction patterns, the fermented chitin belonged to α-chitin. More than 60 volatiles were identified from the fermentation broth after chitin extraction using gas chromatography-ion transfer spectrometry analysis. L. fermentum fermentation decreased the intensities of volatile compounds related to unsaturated fatty acid oxidation or amino acid deamination. By contrast, much more pleasant flavors related to fruity and roasted aroma were all enhanced in the fermentation broth. Our results suggest an efficient one-step fermentation technique to recover chitin and to increase aroma and flavor constituents from shrimp by-products.

Influences of Spices on the Flavor of Meat Analogs and Their Potential Pathways.

This study evaluated the correlation between the sensory characteristics and spices of 50 commercial meat analogs and selected 4 spices to improve the flavor characteristics of soy protein concentrate (SPC) extrudates. Volatile compounds in extrudates and commercial meat analogs were investigated using headspace solid-phase microextraction and gas chromatography-mass spectrometry. The total concentrations of off-flavor volatile compounds in commercial products decreased with an increasing degree of processing. Furthermore, after adding spices during extrusion, the concentrations of volatile compounds such as aldehydes, alcohols, and furans related to thermal treatment decreased by approximately 5-39%, 5-15%, and 11-56%, respectively. Among them, compounds such as nonanal, 2-pentlyufuran, and 1-octen-3-ol, typical off-flavors in soy-based food, decreased by 8-42%, 11-55%, 2-52%, respectively. The correlation analysis between the antioxidative abilities of spices and volatile compounds showed that the contents of total phenolics were negatively correlated with the contents of ketones and alcohols in extrudates (p < 0.001). Moreover, the aroma-active compounds in extrudates were changed. More pleasant compounds, including alkanes and olefins, were observed by adding different spices as well. Especially in black pepper treated extrudates, the OAV value of off-flavor volatile compounds such as hexanal, octanal, 2-pentlyfuran decreased. In conclusion, the addition of spices can reduce off-flavor compounds related to thermal reactions, such as oxidation and the Maillard reaction, and impart newly pleasant flavors to extrudates during the extrusion of SPC. It is important to explore new methods that can be used to improve the flavor of extrudates so that consumers' preferences of meat analog products can be improved.

Screening, Identification and Physiological Characteristics of Lactobacillus rhamnosus M3 (1) against Intestinal Inflammation.

The probiotic role of lactic acid bacteria (LAB) in regulating intestinal microbiota to promote human health has been widely reported. However, the types and quantities of probiotics used in practice are still limited. Therefore, isolating and screening LAB with potential probiotic functions from various habitats has become a hot topic. In this study, 104 strains of LAB were isolated from and identified in traditionally fermented vegetables, fresh milk, healthy infant feces, and other environments. The antibacterial properties-resistance to acid, bile salts, and digestive enzymes-and adhesion ability of the strains were determined, and the biological safety of LAB with better performance was studied. Three LAB with good comprehensive performance were obtained. These bacteria had broad-spectrum antibacterial properties and good acid resistance and adhesion ability. They exhibited some tolerance to pig bile salt, pepsin, and trypsin and showed no hemolysis. They were sensitive to the selected antibiotics, which met the required characteristics and safety evaluation criteria for probiotics. An in vitro fermentation experiment and milk fermentation performance test of Lactobacillus rhamnosus (L. rhamnosus) M3 (1) were carried out to study its effect on the intestinal flora and fermentation performance in patients with inflammatory bowel disease (IBD). Studies have shown that this strain can effectively inhibit the growth of harmful microorganisms and produce a classic, pleasant flavor. It has probiotic potential and is expected to be used as a microecological agent to regulate intestinal flora and promote intestinal health. It can also be used as an auxiliary starter to enhance the probiotic value of fermented milk.

Knowledge, practices and beliefs of students regarding health effects of shisha use in Ouagadougou, Burkina Faso: A cross‑sectional study.

The tobacco epidemic is one of the biggest public health threats the world has ever faced. Shisha use has recently been gaining increased popularity in many developed and developing countries. To determine the prevalence of shisha use among students in Ouagadougou, Burkina Faso, and associated knowledge, smoking practices and beliefs about health effects. A total of 443 students were selected for this cross-sectional study, using a stratified sampling method. Data on shisha use, knowledge about shisha, shisha smoking practices, and factors associated with use of shisha were collected via a questionnaire. The association between the independent variables and shisha use was assessed using a χ² test (p<0.05). Binary logistic regression analysis was used to determine variables that were independently associated with shisha smoking. Of the 421 respondents, 162 (38.5%) indicated that they had smoked shisha; 14.0% were regular smokers. We found that 183 students (43.5%) had poor knowledge about the health effects of shisha. The main reasons for shisha smoking were being in the company of friends who were users (57.4%), the pleasant flavour and fragrance of shisha (25.9%), and fashion (22.2%). Ninety-nine shisha smokers (61.1%) also consumed alcohol. Factors associated with shisha smoking included age <20 years (p<0.001), gender (p=0.034), and educational level of the respondent's father (p=0.0001) and mother (p=0.0004). We found a relatively high prevalence of shisha smoking among the students, and that 43.5% of them had poor knowledge about its effects on health. Developing surveillance, intervention and regulatory/policy frameworks specific to shisha has become a public health priority. What the study adds. The study provides additional data from resource-poor settings such as Burkia Faso, where there is an overall high prevalence of Sisha smoking, and also among students who are poorly informed about the health effects of smoking. Implications of the findings. The data informs advocacy and intervention strategies to combat smoking and decrease overall tobacco use in an African setting.

Determination of healthy natural antioxidants in selected muskmelon (Cucumis melo) cultivars

Muskmelon (Cucumis melo L.) is a popular summer fruit consumed all over the world due to the combination ofrefreshingly sweet taste, pleasant flavour and nutritional value. Melon fruit is characterized by germplasm variabilitywith superior quality. This study aimed to evaluate 5 promising local muskmelon cultivars (Maazoun, Galaoui,Stambouli, Trabelsi, Asli) for some physicochemical characteristics, the content of different bioactive compoundsand the antioxidant activity. The experiments were conducted for two consecutive years 2018 and 2019 at the support station of the inter-professional vegetable group positioned in the North East of Tunisia. Significant differences were observed across the melon cultivars (P&lt;0.05) for soluble solids (9–12°Brix), pH (5.5–6.6), carotenoid (7.5–59.5 mg/ kg FW), phenolic (400–1390 mg GAE/kg FW), flavonoid (251.3–390 mg RE/kg FW), vitamin C (138.2–193 mg/kg FW) contents, as well as hydrophilic (102.28–285.43 μM Trolox/100 g FW) and lipophilic (30–180.22 μM Trolox/100 g FW) antioxidant activities. Galaoui showed the highest levels of carotenoids, phenolics, flavonoids, vitamin C and antioxidant activities followed by Stambouli. Trabelsi cultivar also had a high level of flavonoids. The enhanced hydrophilic antioxidant activity in Galaoui was significantly correlated to phenolic content (r = 0.91). These findings proved that besides being refreshing summer fruit, muskmelon can be considered a promising healthy produce with a superior potential source of natural antioxidants.