Sour Odor Research Articles

Effect of different freezing temperatures on the physical, technological, and organoleptic properties of aged semimembranosus muscles from farmed fallow deer (Dama dama)

Although venison could play an important role in human nutrition, this meat remains undervalued and still contributes very little to the formal meat industry. Moreover, information on processing methods of fallow deer meat and overall quality is still very limited. The objective of this study was to determine how physical, technological, and organoleptic properties differ between 14-day-aged vacuum-packaged fallow deer meat stored either chilled or frozen at different temperatures (-10°C, -18°C, -40°C and -80°C) for six months. Physical, technological, and organoleptic analyses were conducted on semimembranosus muscles (SM) obtained from farmed fallow deer bucks (n = 10). Freezing significantly increased meat redness, yellowness, chroma values, cooking loss and tenderness compared to fresh meat but did not affect pH values, lightness, thawing, or grilling loss. Mean pH readings were 5.5–5.6, being highest in the samples measured one day after slaughter. Freezing at -80°C had the most pronounced effect on some sensory attributes, namely, the highest game meat aroma intensity, sour odour, sour flavour and the lowest chewiness. The findings indicate that a freezing temperature of -18°C and subsequent slow thawing might be preferential in terms of maintaining fallow deer meat quality.

Application of Highly Digestible Fermented Corn Protein Powder in Fecal Low-Odor Adult Dog Feed

This study aimed to develop fecal low-odor adult dog feed using processed corn protein powder as the primary raw material and evaluate its effectiveness through feeding experiments. The objectives included analyzing the fundamental nutritional indicators, comparing the quality of fecal low-odor adult dog feed with commercially available dog feed, and assessing the changes in the eating behavior, physical condition, and physiological and biochemical indicators before and after feeding on the fecal low-odor adult dog feed. This study involved formulating dog feed using processed fermented corn protein powder and conducting nutritional analyses to compare moisture, crude protein, ash, crude fat, and starch contents. Physical properties such as hardness and cohesion were also evaluated. Feeding experiments were conducted with adult dogs to monitor the changes in the eating behavior and physical condition. Physiological and biochemical indicators, including ammoniacal nitrogen and putrefactive odor in feces, were measured both before and after feeding to assess the impact of the fecal low-odor adult dog feed. The analysis showed no significant difference in moisture (p > 0.05), crude protein (p > 0.05), ash (p > 0.05), crude fat (p > 0.05), and starch (p > 0.05) contents between the fecal low-odor adult dog feed and commercially available dog feed. Similarly, no significant difference was noted in the hardness (p > 0.05) and cohesion (p > 0.05) between the two types of dog feed. Both types of dog feed contained rich volatile compounds with varying compositions. The commercially available dog feed had a sour odor, whereas the fecal low-odor adult dog feed had a barbecue and resin-like smell. After feeding with the fecal low-odor adult dog feed, the liquid nitrogen content significantly decreased (p < 0.01). Also, the indole content, a major contributor to fecal odor, based on the data, decreased after feeding.

Chemical composition of sausages processed with starter cultures Lactobacillus curvatus and Lactococcus lactis subsp. lactis during storage in vacuum packaging

Sausages belong to the category of cooked meat products with a short shelf life, which is associated with their rapid spoilage and unsuitability for consumption. One of the ways to extend the shelf life of sausages is the use of biopreservatives, including cultures of lactic acid bacteria. The aim of the study was to determine the chemical composition and organoleptic characteristics of "Juicy" sausages processed with a starter culture of Lactobacillus curvatus or a mixture of starter cultures Lactobacillus curvatus + Lactococcus lactis subsp. lactis before vacuum packaging and storage in a chilled state. Storage of sausages in the control variant in vacuum packaging in a chilled state for up to 18 days did not affect the moisture, protein, fat, and ash content, but on the 21st day, their spoilage was observed in the form of appearance of cloudy juice, sliminess, sour odor, and delamination of the vacuum packaging. Processing sausages with a starter culture of Lactobacillus curvatus or a mixture of starter cultures Lactobacillus curvatus + Lactococcus lactis subsp. lactis before vacuum packaging did not affect the moisture, protein, fat, and ash content up to 30 days of storage in a chilled state. On the 36th day, spoilage of sausages was observed in both variants of treatment with lactic acid bacteria cultures, characterized by the appearance of cloudy juice, sour odor, and delamination of the vacuum packaging. The pH value of sausages in both variants of treatment with lactic acid bacteria cultures decreased throughout the storage period and reached a level of 6.05 and 5.91 units on the 30th day. Processing sausages with either a single culture or a mixture of lactic acid bacteria cultures extends their shelf life in a chilled state by 12 days. The obtained results may justify the use of microbial biopreservatives for the production of cooked sausage products, which will help reduce losses due to spoilage during storage in vacuum packaging in a chilled state. The use of a mixture of lactic acid bacteria cultures for processing sausages requires further research and may be effective in case of detection of aerobic spoilage microorganisms.

Study of volatile compounds and sensory profile of Brazilians’ cocoa liquors

The present work aimed to evaluate the volatile compounds and sensory profile of liquors from different Brazilian states and from Cotê d’Ivoire. A trained panel analyzed samples for their intensity of several flavors by Descriptive Analysis and volatile compounds were evaluated by chromatography-mass spectrometry. Results showed that liquors from Pará and Cotê d’Ivoire presented a relation to chocolate and floral flavors, respectively, meanwhile those organic from Pará presented high acidity flavors. Liquors from Pará and Cotê d'Ivoire were related to chocolate and floral flavors. Samples from Bahia were slightly related to woody and cocoa flavors, meanwhile cocoas from Rondônia and Espírito Santo were related to musty, smoked, burned flavors. Chocolate flavor was related to volatile compounds with recognized roasted and nut odors. Acidity flavor was statistically tracked with compounds with flowery and fruit odors. Smoked and woody flavors were tracked to compounds with pungent, rancid and sour odors, and 1-octanol and 1H-Indole (burned notes). Fruity, sweety and flowery compounds composed the green flavor. Burned flavor was linked to waxy and rancid compounds. The intensity of musty was related to the presence compounds with citrus and cocoa odors. Cocoa attribute was statistically related to compounds with flowery and fruity odors.

Lycium barbarum Is a New Host of Botryosphaeria dothidea Associated with Soft Rot Disease in China.

Goji berry (Lycium barbarum) is a plant of the Solanaceae family that is cultivated in the Chinese provinces of Xinjiang, Ningxia, Gansu, and Qinghai, and its fruit is used as a traditional Chinese medicine (Yossa Nzeuwa et al. 2019). In July 2019, fruit rot was observed at an incidence of 20 to 25% on the Goji berry at a fruit market in Yinchuan, Ningxia, China. The fruit symptoms began as slightly shriveled areas on fruit peel, with noticeable softening of the infested portion of the tissue, followed by rotting and a sour odor. To isolate the pathogen, ten symptomatic tissues were randomly collected from different boxes, surface-sterilized for 30 s with 75% ethanol, followed by 0.1% mercuric chloride, then rinsed in sterile distilled water three times and plated onto PDA. The plates were incubated at 25°C in the dark for 7 days. Five purified fungal isolates from different fruit were obtained and single-spores. Emergent fungal colonies were white with 1 to 3 mm white margins and abundant aerial hyphae, 1 to 6 mm high, that became dark gray after 4 to 5 days. Conidia were hyaline, unicellular, fusiform, and measured 19.3 to 28.2 μm× 3.8 to 6.4 μm (n=50). All the morphological characteristics were consistent with Botryosphaeria spp. (Slippers et al. 2004). Five representative isolates, BJN1-BJN5, were selected for molecular identification. Total genomic DNA of the isolates was extracted with a Plant/Fungi DNA Isolation Kit. Translation elongation factor 1-alpha (EF1) gene and internal transcribed spacer (ITS) regions were amplified with primers EF1-728F/986R (Carbone and Kohn 1999) and ITS1/ITS4, respectively. The sequencing results of the five isolates were consistent, and those of the isolate BJN1 we deposited in the NCBI GeneBank database for EF1 (MK733274) and ITS (MK359291). A BLAST search of the GenBank database indicated that the EF1 and ITS sequences had 100% and 99% similarity, respectively, to B. dothidea ex-type strain (AY236898 and KF766151). A phylogenetic tree was constructed using maximum parsimony methods in MEGA11 and BJN1 isolate clustered with the reference sequence of B. dothidea. Pathogenicity tests were performed, inoculating healthy fruit with both mycelial plugs (7 days old) and conidial suspension (1 × 106 conidia/ml), repeated three times. Mycelial plugs of five isolates (BJN1-BJN5) growing on PDA with a colony diameter of 4 mm were placed on the sterilized surface of 20 Goji berry fruit. Sterile PDA plugs were placed on 12 healthy fruit as a control. In a second test, conidial suspensions of five isolates were sprayed on the surface of 20 healthy fruit and sterilized distilled water was used as a control. The inoculated fruits were maintained in an artificial climate chamber at 25°C and 80% to 85% relative humidity with a 12-h photoperiod for 7 days. The development of soft rot, similar to that observed on the original samples, was observed on inoculated fruit while control fruits remained asymptomatic. The pathogen was reisolated from infected fruit and confirmed as B. dothidea based on morphological characteristics and molecular sequences. To our knowledge, this is the first report of B. dothidea causing postharvest fruit rot of Goji berry, and this pathogen has been reported to cause fruit rot in Kiwifruit (Li et al. 2016) and Yellowhorn (Liu et al. 2018). This study provides information on a new postharvest fruit rot of Goji berry in China that has the potential to cause economic losses.

The Effect of Sumac (Rhus coriaria L.) Application on Oxidation Status, Sensory Attributes, Physicochemical and Microbiological Parameters of Carp (Cyprinus carpio) Fish during Chilled Storage

The aim of this study was to evaluate the impact of sumac on the oxidation status, sensory properties, and physicochemical and microbiological parameters of common carp (Cyprinus carpio) fish during chilled storage. Fillets of carp were treated with ground sumac at percentages of 0% (T0), 0.5% (T1), 1.5% (T2) and 2.5% (T3) and analysed after 24 and 72 h of chilled storage. The fat content, oxidation parameters (thiobarbituric acid reactive substances, TBARS), antioxidant capacity, total volatile basic nitrogen (TVB-N), free fatty acids (FFA), sensory properties, colour indicators (lightness L*, redness a*, yellowness b*), water activity, pH value, aerobic plate count (APC), psychrotrophic microorganism count (PMC), and coliform bacteria count were determined. The TBARS values of T1, T2, and T3 decreased significantly (p < 0.05) after 24 h of chilled storage. The antioxidant capacity increased in a dose-dependent and time-dependent manner. As regards organoleptic properties, sumac was able to reduce the natural fishy odour, increase the sour odour and flavour, and mask the fish odour and flavour significantly. A significant effect of sumac on the redness (a*) values of muscles was observed, which increased with elevation of the sumac ratio. A decrease in fillet pH and lower APC and PMC were observed. No effect was found on water activity or the growth of coliform bacteria. The study found that sumac plays a role in the oxidation status, pH value and organoleptic properties of fish fillets, which could be beneficial for the fish and fishery products industry.

Use of sensory and physico-chemical parameters to understand consumer perception of attiéké, a fermented cassava product.

Cassava breeding research programs focused initially on agronomic performance but in recent years they have considered the processability and the organoleptic properties of the final product, to increase the adoption of new varieties. One important cassava foodstuff is attiéké, a fermented and granular product, so it is necessary to determine criteria used by attiéké processors to select raw cassava and the characteristics leading consumers to like this product. This study assessed the attiéké production process, the criteria associated with the quality of attiéké, the sensory drivers of consumer acceptance, and their thresholds. The total processing yield of attiéké varied according to the cassava variety and depended primarily on the fermentation-pressing yield. However, it was not correlated either with the peeling yield or with morphological characteristics of cassava roots. The production of a ton of attiéké required about 150 h. Dry matter, organic acids, soluble sugars, total pectin, and the pH of raw material and attiéké varied depending on the cassava variety. Ten discriminating sensory attributes of attiéké were identified. Consumer testing showed that overall liking for attiéké was associated with sourness, texture, and brightness. Acceptable sensory score thresholds were 1.67-2.18 for sour odor, 4.75 to 6.3 for cohesiveness, and 5.4 to 6.3 for 'mouthfeel sensation'. Attiéké dry matter correlated positively with cohesiveness and moldability. Several potential solutions are discussed to improve the adoption of cassava varieties for attiéké production. However, further studies need to be carried out to translate the sensory thresholds of texture attributes into robust instrumental methods because texture is an important attribute of attiéké in addition to sourness. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Analysis of aroma quality changes of large-leaf black tea in different storage years based on HS-SPME and GC–MS

The reasons for the change in volatile metabolites and aroma of black tea during storage remain unclear. Therefore, we used HS-SPME and GC–MS methods to analyze the aroma compounds of new tea (2021) versus aged tea groups (2015, 2017, and 2019). A total of 109 volatile components were identified. During storage, 36 metabolites mainly with floral and fruity aromas decreased significantly, while 18 volatile components with spicy, sour, and woody aromas increased significantly. Linalool and beta-ionone mainly contributed to sweet and floral aromas of freshly-processed and aged black tea, respectively. Isovaleric acid and hexanoic acid mainly caused sour odor of aged black tea. The monoterpene biosynthesis and secondary metabolic biosynthesis pathways might be key metabolic pathways leading to changes in the relative content of metabolites during storage of black tea. Our study provides theoretical support for fully understanding the changes in the aroma quality of black tea during storage.

Dynamic Changes in Flavor and Microbiota in Traditionally Fermented Bamboo Shoots (Chimonobambusa szechuanensis (Rendle) Keng f.).

Dissecting flavor formation and microbial succession during traditional fermentation help to promote standardized and large-scale production in the sour shoot industry. The principal objective of the present research is to elucidate the interplay between the physicochemical attributes, flavor, and microbial compositions of sour bamboo shoots in the process of fermentation. The findings obtained from the principal component analysis (PCA) indicated notable fluctuations in both the physicochemical parameters and flavor components throughout the 28 day fermentation process. At least 13 volatile compounds (OAV > 1) have been detected as characteristic aroma compounds in sour bamboo shoots. Among these, 2,4-dimethyl Benzaldehyde exhibits the highest OAV (129.73~668.84) and is likely the primary contributor to the sour odor of the bamboo shoots. The analysis of the microbial community in sour bamboo shoots revealed that the most abundant phyla were Firmicutes and Proteobacteria, while the most prevalent genera were Enterococcus, Lactococcus, and Serratia. The results of the correlation analysis revealed that Firmicutes exhibited a positive correlation with various chemical compounds, including 3,6-nonylidene-1-ol, 2,4-dimethyl benzaldehyde, silanediol, dimethyl-, nonanal, and 2,2,4-trimethyl-1,3-pentylenediol diisobutyrate. Similarly, Lactococcus was found to be positively correlated with several chemical compounds, such as dimethyl-silanediol, 1-heptanol, 3,6-nonylidene-1-ol, nonanal, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyl phthalate, and TA. This study provides a theoretical basis for the standardization of traditional natural fermented sour bamboo production technology, which will help to further improve the flavor and quality of sour bamboo.

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.

Organoleptic Test of Eco-enzyme : Fermentation of Banana Peel Waste

Prevention of environmental damage can be done by recycling household waste both organic and inorganic. One of them is by making eco-enzymes made from banana peel waste which is found in the environment. This study aims to determine the level of respondents' liking based on organoleptic test variables. This research method is an experiment that includes making eco-enzymes, and organoleptic tests consisting of aroma, color and texture variables. Data analysis was carried out in a qualitative descriptive way by looking at the level of respondents' liking. The results showed that the average respondent chose a brown color with a percentage of 90%, yellow 7%, and colorless 3%. The scent variable respondents chose sour odor by 70% and other aromas 30%. While the texture of all respondents chose the composition of liquid eco-enzyme. This is due to the metabolic activity of microorganisms that result in the breakdown of substrates by bacteria resulting in changes in the aroma, color and texture of banana peels. The conclusion of this study is that the use of banana peel as the basic ingredient for making eco-enzyme affects the respondents' level of liking. Eco-enzyme can be used as a natural fertilizer for plant growth and can reduce household waste.

KUALITAS PRODUK CASCARA CELUP DENGAN PENAMBAHAN JAHE MERAH (Zingiber officinale var. Rubrum)

Cascara is a herbal beverage product derived from processed coffee skin waste. However, the acidic odor of cascara is not favored by consumers. To improve the quality of cascara, is to combine them with red ginger (Zingiber officinale var. Rubrum). Red ginger contains volatile components such as zingiberene and zingiberol, which provide a distinctive fresh aroma that can mask the sour odor of cascara. The purpose of this study was to determine the effect of different ratios of cascara and red ginger on the physical, chemical, organoleptic, and microbiological quality of tea bags containing cascara with added red ginger, in order to obtain the best formulation. This research was conducted using a randomized complete block design (RCBD) with four treatment ratios: T0 (100% cascara: 0% red ginger), T1 (90% cascara: 10% red ginger), T2 (80% cascara: 20% red ginger), T3 (70% cascara: 30% red ginger), and T4 (60% cascara: 40% red ginger). The different ratios of cascara and red ginger significantly influenced the physical, chemical, organoleptic, and microbiological properties of the tea bags containing cascara with added red ginger. The best formulation was obtained from treatment T3 (70% cascara: 30% red ginger), which had a color preference rating of 4.15, an aroma preference rating of 4.34, a taste preference rating of 4.17, an L* value of 32.377, a pH value of 5.05, a moisture content of 13.461%, a total phenol content of 21.105 mg GAE/g, an antioxidant activity of 68.115%, and a total microbe count of 3.36 × 103 CFU/ml.

The Quality of Physic and pH of Gama Umami Grass Silage Supplemented with Calliandra Leaves and Pollard

This research was conducted to examine the pH value and physical quality of Gama Umami grass silage which was supplemented with legume and pollard. This study used a completely randomized design with 4 types of treatments, they were P0: GU grass 95% + calliandra 5%; P1: GU grass 90% + Calliandra leaves 10% + pollard 2.5%; P2: GU grass 80% + Calliandra leaves 20% + pollard 5%; P3 : GU grass 70% + Calliandra leaves 30% + pollard 7.5%. Each treatment was replicated 5 times. The ensilage was carried out for 21 days. The results obtained were then tested for pH and physical quality which included color, odor, texture, and the presence of fungi. The best pH results were found in P1, however, calliandra and pollard supplementation for Gama Umami grass silage had no significant effect (P<0.05). Meanwhile, in the physical quality test, P3 has better quality than the other 3 treatments. It was concluded that the supplementation of calliandra and pollard at P3 produced a physical quality of color close to silage material, sour odor, no slimy texture, and no fungus found.

Starter culture growth dynamics and sensory properties of fermented oat drink

In the present study, an oat drink, a plant-based alternative to dairy products, was developed by fermenting the oat base with different vegan starter cultures. The desired pH below 4.2 was achieved in 12 h, regardless of starter culture used. Metagenomic sequencing revealed that S. thermophilus was the dominating species, ranging from 38% to 99% of the total microbial consortia. At lower pH values, population of L. acidophilus, L. plantarum and L. paracasei continued to increase in fermented oat drinks. Lactic acid was produced between 1.6 and 2.8 g/L. The sensory panel showed that all fermented oat drinks had a sour odor and taste. The volatile compounds identified belonged to the ketone, alcohol, aldehyde, acids, and furan classes. The concentration of the most preferred volatile components, such as diacetyl and acetoin, increased during fermentation. However, sensory evaluation showed that all samples were associated with cereals and not dairy in terms of taste and odor. Rheological analysis showed the formation of weak gel-like structures in fermented oat drinks. Overall, fermentation improved flavor and texture of the product. This study provides a broad overview of the oat drink fermentation process from the perspectives of starter culture growth, microbial consortium dynamics, lactic acid bacteria metabolism, and sensory profile formation.

Correlation between microorganisms and flavor of Chinese fermented sour bamboo shoot: Roles of Lactococcus and Lactobacillus in flavor formation

Sour bamboo shoot is a popular traditional fermented vegetable in southern China. The current study aims to clarify the relationship among physicochemical properties, flavor, and microbial compositions of sour bamboo shoots during fermentation. Four organic acids (OAs) were considered to be the main acids in sour bamboo shoots. At least 7 volatile compounds (OAV >1) were identified as the characteristic aroma substances, especially p-cresol, which accounted for the sour odor of sour bamboo shoots. The microbial community showed that Firmicutes and Proteobacteria were the dominant phyla, while Lactococcus and Lactobacillus were the dominant genera in sour bamboo shoots. Correlation analysis indicated that Firmicutes positively correlated with p-cresol, phenol, 2-methoxy-phenol, malic acid, total titratable acidity (TTA), and some OAs. Lactococcus was positively correlated with phenol, 2-methoxy-phenol, benzyl alcohol, TTA, some OAs, and amino acids (AAs). This study provided a theoretical basis for screening indigenous aroma-producing microorganisms as the starter of sour bamboo shoots.

Identification of odour compounds emitted by wooden boards with the presence of indoor ozone

Indoor volatile organic compounds (VOCs) produce odours that reduce perceived air quality. Furnitures and indoor decoration are the main sources of indoor VOCs. Considering the increase in outdoor and indoor ozone concentrations, ozone, as a strong oxidant, can have an impact on indoor odour. Herein, medium-density fibreboard (MDF) and flame retarded plywood (FRP) were selected as experimental materials, and gas chromatography-olfactory-mass spectrometry (GC-O-MS) was performed to identify the odour compounds emitted by materials with and without 100 ppb ozone. MDF1, MDF2 and FRP emitted 6, 8 and 14 different odour compounds, respectively. MDF2 emitted moderate grassy and sour odours. FRP emitted moderate grassy, fruity, rubber and pine incense odours. After 8 h of exposure to ozone at a concentration of 100 ppb, MDF1, MDF2 and FRP emitted different odour compounds, respectively. The characteristic odours of MDF were aggravated. Except for pine incense odour, the intensity of other characteristic odours of FRP was weakened. Through cluster heatmap analysis and principal component analysis, the characteristic odour compounds of MDF and FRP were further clarified. Introducing a SOI model, the results showed that ozone exposure increased the SOI of MDF1 and MDF2 from 3.34 to 4.22 and from 4.11 to 4.44, respectively, and that the odour intensity of FRP decreased from 3.78 to 3.41. It can be determined that ozone may have opposite effects on the odour emitted by different materials. The results clarify the target pollutants for odour control research on wooden board emissions.

Bacterial Community Structure in Sago Pith and Sago Waste Water and Its Potential Uses as Organic Acids Producer

Sago is one of commodities in South Sulawesi. The extraction process of sago flour produces waste water that still contains organic matter and smells sour. So, it has the potential as a pollutant. The sour odor produced allows the presence of acid-producing bacteria that can be used for waste treatment. The objective of this research is to explore the bacterial community structure in sago pith and sago waste water through high-throughput sequencing technology and its potential uses as organic acids producer. Samples were obtained from a traditional sago factory in Palopo City, South Sulawesi, Indonesia. The acidity degree, total dissolve solid, and temperature were measured in the sago pool at the sampling area, while the nutrient contents were analyzed by titration method in Testing Laboratory of Food Quality and Food Safety, Brawijaya University. Bacterial cells in the sago waste water were acquired through a multilevel filtering process on filter paper with pore nitrocellulose membrane sizes of 0.45 and 0.20 µm. Total DNA trapped in the nitrocellulose membrane with pore size of 0.20 µm was isolated using FastDNA Spin Kit (MPBIO) and the V3-V4 regions of 16S rDNA (341f-806r) were amplified. Amplicons were analyzed by Miseq of Illumina and further analyzed by Muscle v.3.8.31, QIIME v.1.7.0, and R v.2.15.3. The result shows that nutrient content in sago pith is higher than in sago waste water. Both samples are dominated by Phylum Proteobacteria and share 189 common bacterial species. The dominant bacteria that can produce organic acid in sago pith are Dysgonomonas sp., Propionispira sp., and Lactobacillus pentosus. While, Lactobacillus mali and Gluconobacter frateurii are the dominant organic acid-producer bacteria in sago waste water. Keywords: Bacterial community structure, Next generating sequencing, Sago pith, Sago wastewater

Evaluation of the cellular and extracellular fluid of the body of calves using bio impedancemetry

Currently, non‐invasive animal research methods continue to develop, one of which is bioelectrical impedance analysis to determine the body's water, fat, fat‐free, and cell mass, which reflects the assessment of the body's liquids. The electrical and biological significance of impedance analysis lies in the fact that the measurement of the resistance (impedance) of the body's tissues or fluids changes during exposure to alternating currents of different frequencies and makes it possible to take into account the totality of resistance or the actual difference between two measurements taken in succession. The research object was newborn calves, healthy (G1) and with enteritis (G2), selected according to the principle of analogs, 15 animals in each group. The impedance measurements were studied using the “BICA” device (body impedance composition analyzer). Enteritis in calves is accompanied by a significant loss of electrolytes and free fluid, affecting normal metabolic processes. In this regard, the study of the liquids of the body of healthy and enteritis‐sick calves was the main goal of the research. The first signs of enteritis appeared more often on the second and third days of life. In G2: a decrease in motor activity, hunchback (calves do not lean well on the chest limbs, the head is lowered down) were shown, a decrease in the sucking reflex, retraction of the eyeballs into the orbits, low skin turgor, a red border on the gums under the arcade of the incisors. Feces in sick calves are unformed, watery, gray‐yellow in color, with a pungent, sour odor. On the tenth day of life in calves with enteritis, the total body fluid decreased, and this indicator was 1.5 times lower than in healthy calves (P &lt;0.01). The decrease in the total body fluid volume mainly occurred due to a decrease in the level of intracellular fluid, which in sick animals was 2.8 times lower than in healthy animals (p &lt;0.001). At the same time, the level of extracellular fluid in calves from the G1 and the G2 did not differ significantly and amounted to 7.9 ± 0.8% and 6.28 ± 1.0%, respectively. After the treatment (diet therapy and enroxil 5%, intramuscularly, at a dose of 1 ml per 20 kg of body weight once a day for 3 days) by the age of twenty days, the volume of total body fluid in calves with enteritis recovered and did not significantly differ from the level in healthy animals. There were no significant differences in the volume of extracellular fluid in the calves of both groups. However, as for the intracellular fluid volume, this indicator in recovered calves was still significantly lower (P &lt;0.05) than in healthy animals and amounted to 12.14 ± 1.0% and 15.48 ± 0, 7% respectively. Thus, from the data obtained, it can be seen that fluid loss occurs mainly due to the intracellular fluid with enteritis in calves. Complete recovery of the liquid sectors in calves was observed only by the age of one month.

First report of Geotrichum candidum causing sour rot of peach in China.

Peach (Prunus persica L. Batsch) is one of the most important fruit crops in China (Wang et al. 2011). Yangshan Town of Jiangsu Province is one of the four major peach producing areas in China, with a growing area of 2,000 ha (Tian et al. 2018). During June 2020, a postharvest disease presenting with brown necrosis and rot occurred on peaches in Yangshan Town. The estimated damage was more than 10% of the total harvest. The symptoms included soft rot, and the lesion appeared sunken, accompanied with sour odor and white mycelia. Twelve peaches with representative symptom were sampled for pathogen isolation. Pieces (about 5 mm × 5 mm) from the lesion edge of symptomatic fruits were dissected and surface disinfected (3% NaClO for 10 s and 75% ethanol for 30 s), then rinsed three times with distilled water, dried on sterile filter paper and transferred to Potato Dextrose Agar (PDA) media plates supplemented with 150 ng/mL streptomycin sulfate. The plates were incubated at 28 ℃ for 3 days. Forty-eight isolations were obtained from the plates and isolates were single-spored. All isolates presented white, flat, milky yeast-like colonies with radial mycelia. Hyphae under microscope were septate, branched, disarticulating into arthroconidia measuring 3.39 to 9.27 × 2.05 to 7.71 μm. The morphological characteristics are consistent with Geotrichum candidum (De Hoog et al. 1986). Internal transcribed spacer (ITS) and 18s nuclear ribosomal small subunit (SSU) of the 48 isolates were amplified and sequenced using the primers ITS5/ITS4, and NS1/NS4 for molecular identification (Schoch et al. 2012). The resulted sequences showed no difference among all the isolates. Alignment by blastn showed the sequence of ITS and SSU were 100% (accession number. GQ376093) and 99.7% identical (accession number. KY977411.1) to Geotrichum candidum, respectively. The sequences of ITS (accession number MW493646) and SSU (accession number MW493648) were submitted to the GenBank. Commercial ripe peaches with the size of about 15 cm × 15 cm × 10 cm was used for pathogenicity test. Peaches were surface disinfected with 75% ethanol, then a wound with 4 mm in diameter and 5 mm in depth was made on the surface of each fruit. Ten peaches were inoculated with 10 μL (1×105 spores /mL) of the isolate suspension. Another ten peaches were inoculated with 10 μL sterile water as the control. Peaches were incubated individually at 28 ℃and a relative humidity of about 85%. After three days, large scale of pits and necrosis appeared on every peach inoculated, and the symptoms were consistent with the diseased peaches in Yangshan Town, while no symptoms non-inoculated on the control peaches were observed. The pathogen was re-isolated from the diseased fruit and was identified again by sequencing of ITS and SSU. All the tests were conducted three times. Considering the evidence, we identified the pathogen as G. candidum. This pathogen has been reported to cause sour rot was reported in kiwifruit, strawberry, melon and other fruits (Alonzo et al. 2020; Cheng et al. 2020; Halfeld-Vieira et al. 2020). To our knowledge, this is the first report of G. candidum causing sour rot of peach in China, which may cause a great loss to peach industry of China.

Characterization of the aroma-active compounds in black soybean sauce, a distinctive soy sauce

Black soybean sauce’s (BSS) aroma was scarcely investigated, which seriously affected BSS’s quality and consumers’ preference. Thus the aroma compounds in BSS were characterized using gas chromatography-mass spectrometry/gas chromatography–olfactometry coupling with recombination and omission experiments. Sensory evaluation showed the fruity odor was increased by 63% and the malty, alcoholic, floral, smoky, caramel-like and sour odors were decreased by 24–35% when compared to the control soy sauce (SS, p < 0.05). Totally, 126 volatile compounds, 44 aroma-active compounds and 22 vital aroma-active compounds were identified in BSS. Compared to SS, BSS exhibited a distinctive aroma characteristics which was caused by significantly higher odor activity values (OAVs) of 3-methylbutyl acetate (357%), ethyl propanoate (144%), ethyl 3-methylbutanoate (70%), ethyl 2-methylbutanoate (102%) and lower OAVs of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (52%), 4-hydroxy-2-ethyl-5-methyl-3(2H)-furan-3-one (50%), ethanol (48%), 4-vinylguaiacol (41%), 3-methylthiopropanal (37%), 3-methylbutanol (33%), 4-ethylguaiacol (28%). The results would contribute to BSS’s quality control and aroma improvement.