Identifying Variables Influencing Traditional Food Solid-State Fermentation by Statistical Modeling.

Mandai is a traditional fermented food made from the inner skin of the cempedak fruit (Artocarpus champeden) and is widely known in South Kalimantan. Its distinctive sour taste is a result of microbial activity during the natural fermentation process. This study highlights the important role of lactic acid bacteria (LAB) as the dominant agents in Mandai fermentation. The main objective of this research is to isolate and characterize LAB from fermented Mandai samples. The methods used in this study include serial dilution, inoculation on Nutrient Agar (NA) media, incubation at room temperature, colony morphology observation, and Gram staining using crystal violet. The results showed the presence of round colonies with a creamy white color and smooth surfaces, which indicate the characteristics of lactic acid bacteria. Most of the isolates showed Gram-positive properties, supporting their identification as lactic acid bacteria. This research not only enriches our understanding of the microbial ecology in Mandai fermentation but also opens up opportunities for utilizing LAB as a natural preservative or functional probiotic in both traditional and modern food products. The presence of LAB in Mandai fermentation suggests the potential to enhance the quality and health benefits of this traditional food, making it a viable source of probiotics beneficial for digestive health. Additionally, the use of LAB in Mandai processing could increase the appeal of this product in broader markets, both locally and internationally. Overall, this study provides a solid foundation for further development in utilizing microbes in traditional food fermentations. Moreover, it opens opportunities to improve the quality and sustainability of Mandai products while raising awareness about the importance of fermentation in enhancing the nutritional value and health benefits of traditional food products.

Bread waste to lactic acid: Applicability of simultaneous saccharification and solid state fermentation

Microbial community structure and interactions between Aspergillus oryzae and bacteria in traditional solid-state fermentation of Jiangqu

Traditional Romanian food products are an integral part of local culture and spirituality. These food traditions have been formed over the centuries and represent a particularly important part ofthe development of a circular economy in rural areas. In order to contribute to the development of this sector of activity we conducted a study on consumer perception of traditional Romanian food products. The purpose of this work was to identify the structure of the studies and the future directions of research related to the image of traditional food products through the bibliometric study, as well as the identification of consumer trends, of these products through a survey based on the questionnaire. The results obtained indicate that traditional Romanian food products are consumed by the majority of respondents participating in the survey and that this sector ofactivity has continuity in its development and presents a clear interest among citizens.

This study aimed to identify specific microorganisms related to the formation of precursors of EC (ethyl carbamate) in the solid-state fermentation of Chinese Moutai-flavor liquor. The EC content was significantly correlated with the urea content during the fermentation process (R2 = 0.772, P < 0.01). Differences in urea production and degradation were found at both species and functional gene levels by metatranscriptomic sequencing and culture-dependent analysis. Lactobacillus spp. could competitively degrade arginine through the arginine deiminase pathway with yeasts, and most Lactobacillus species were capable of degrading urea. Some dominant nonconventional yeasts, such as Pichia, Schizosaccharomyces, and Zygosaccharomyces species, were shown to produce low amounts of urea relative to Saccharomyces cerevisiae. Moreover, unusual urea degradation pathways (urea carboxylase, allophanate hydrolase, and ATP-independent urease) were identified. Our results indicate that EC precursor levels in the solid-state fermentation can be controlled using lactic acid bacteria and nonconventional yeasts.

Microflora for improving the Auricularia auricula spent mushroom substrate for Protaetia brevitarsis production

Single step fermentation of starch to l(+) lactic acid by Lactobacillus amylophilus GV6 in SSF using inexpensive nitrogen sources to replace peptone and yeast extract – Optimization by RSM

Considering the large amounts of by-products derived from orange processing, which are generally discarded, the present study aimed to explore the feasibility of using orange peel for lactic acid production in solid state fermentation. Different species of lactic acid bacteria were employed, singly and in co-culture, to evaluate their ability to ferment orange peel and produce lactic acid. Among the single cultures tested, Lactobacillus casei 2246 was the most efficient strain, reaching the highest concentration of lactic acid (209.65 g kg-1 ) and yield (0.88 g g-1 ). The use of Lactobacillus plantarum 285 and Lactobacillus paracasei 4186 in co-culture produced a comparable amount of lactic acid, showing a better performance than the same strains in single cultures. Orange peels represent a suitable raw material for solid state fermentation employing lactic acid bacteria. Lactic acid was obtained that consumed the most of sugars available, leading to high yields. Despite all the strains tested showing the same growth ability, different peculiarities in lactic acid production were revealed, dependent on the species/strains, suggesting the relevance of strain selection. © 2019 Society of Chemical Industry.

Rosy vinegar is a well-known traditional Chinese product whose flavour is affected by its lactic acid content. In this study, Lactobacillus bacteria were employed to increase the content of lactic acid during the ethanol fermentation stage. The optimised fermentation parameters were determined as an inoculation amount of 3% (v/v), a temperature of 30 degrees C and an initial pH value of 4.0. Fermentation under these optimal conditions resulted in an alcohol degree of 6.2% (v/v), a total acidity of 49.5 g L(-1) and a lactic acid content of 4.14 g L(-1). The content of lactic acid (4.14 g L(-1)), which approached the level achieved by solid state fermentation, was 3.56-fold higher than that in vinegar fermented without lactic acid bacteria (1.16 g L(-1)). The results indicate that mixed fermentation with Lactobacillus plantarum and Saccharomyces cerevisiae strains greatly increases the lactic acid content and improves the flavour of rosy vinegar.

The effect of different extraction and purification conditions on the microbial protein obtained from solid-state fermentation (SSF) and the effect of periodical dynamic changes of air on protein have been studied. The mechanism of solid-state fermentation with periodical dynamic changes of air is also discussed. Compared with static solid-state fermentation, periodical dynamic changes of air afford a higher protein mass; from 1 g of the fermentation microbe, 5.3 mg of the intracellular protein (an increase of 34.63%) and 9.09 mg of the extracellular protein (an increase of 17.8%) were obtained on the sixth day of fermentation. The filter paper activity and carboxymethyl cellulose activity (FPA and CMCase) of the extracellular protein are 1.739 μmol/s and 109.592 μmol/s, respectively, which represent increases of 60.1% and 21.2% over the corresponding values for static solid-state fermentation. The FPA and CMCase of the intracellular protein are 0.245 μmol/s and 6.392 μmol/s, respectively, which represent decreases of 22.2% and 38.7% over the corresponding values for static solid-state fermentation. The enzyme activity of the microbial extracellular protein in solid-state fermentation with periodical dynamic changes of air on the fifth day is nearly equal to that on the sixth day without periodical dynamic changes of air, so the period of fermentation can be shortened. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) experiments suggest that pulsating air pressure stimulation leads to a decrease in the amount of protein component with molecule mass of about 80400Da, and an increase in the amount of protein component with molecule mass of about 28520Da.

SUMMARYResearch backgroundHeat-stabilised defatted rice bran (HSDRB) is a primary by-product of rice bran oil extraction industry and a nutritious source of protein. However, despite the unique nutritional profile of rice bran protein, the protein-rich by-product, HSDRB is underutilised as a low-value animal feed. Research on protein extraction from HSDRB by enzymatic hydrolysis has attracted the attention of numerous scientists. However, a cost-effective extraction method is required to mitigate the high costs associated with the use of enzymes. Therefore, we have presented an alternative economical and natural approach for protein extraction from HSDRB by solid-state fermentation (SSF) with heterofermentative microbes.Experimental approachSSF of HSDRB with two types of traditional Asian fermentation starters, namely loog-pang and koji, were evaluated for enzyme production and their efficacy in extracting proteins from HSDRB. For this purpose, HSDRB fermentation was carried out for 0, 12, 24, 48, 72 and 96 h followed by 24-hour hydrolysis to evaluate the extracted rice bran protein. In addition, microbiome diversity in the fermentation starters was also determined by metagenomic sequencing of 16S rRNA and internal transcribed spacer to identify bacteria and fungi, respectively.Results and conclusionsThe microbial community in the fermentation starters showed the dominance of lactic acid bacteria (LAB) such as Bacillus subtilis in loog-pang and Streptococcus lutetiensis, Bacillus pumilus, Lactococcus cremoris, Lactococcus garvieae and Pediococcus pentosaceus in koji, while yeast species Saccharomycopsis fibuligera and Saccharomyces cerevisiae dominated the fungal diversity in loog-pang and koji starters, respectively. The results suggest that loog-pang and koji can produce cellulase, neutral and acid proteases during fermentation. Despite the discrepancy in their microbial diversity and the enzyme activity during SSF, both starters could effectively increase protein extraction from HSDRB. A positive relationship between the SSF duration and extracted protein was observed. During SSF with loog-pang and koji after 72 h followed by 24-hour hydrolysis, 65.66 and 66.67 % protein was extracted from HSDRB, respectively. The amino acid analysis of the protein hydrolysate produced by the non-fermented and fermented methods showed no difference and had an abundance of glutamic and aspartic acids, leucine, arginine, alanine and glycine amino acids, which accounted for approx. 58 % of the total amino acids.Novelty and scientific contributionLoog-pang and koji (traditional Thai and Japanese fermentation starters, respectively) were found to be effective in extracting proteins from HSDRB by SSF although they are inexpensive microbial enzyme sources. Future research aimed at scaling up HSDRB protein extraction for usage in industrial applications can draw on our results.

Innovations in traditional foods: Impact on perceived traditional character and consumer acceptance

Solid-state fermentation (SSF) has been widely used in the processing of sorghum grain (SG) because it can produce products with improved sensory characteristics. To clarify the influence of different microbial strains on the SSF of SG, especially on the polyphenols content and composition, Lactiplantibacillus plantarum, Saccharomyces cerevisiae, Rhizopus oryzae, Aspergillus oryzae, and Neurospora sitophila were used separately and together for SSF of SG. Furthermore, the relationship between the dynamic changes in polyphenols and enzyme activity closely related to the metabolism of polyphenols has also been measured and analyzed. Microstructural changes observed after SSF provide a visual representation of the SSF on the SG. After SSF, tannin content (TC) and free phenolic content (FPC) were decreased by 56.36% and 23.48%, respectively. Polyphenol oxidase, β-glucosidase and cellulase activities were increased 5.25, 3.27, and 45.57 times, respectively. TC and FPC were negatively correlated with cellulase activity. A positive correlation between FPC and xylanase activity after 30 h SSF became negative after 48 h SSF. The SG surface was fragmented and porous, reducing the blocking effect of cortex. Cellulase played a crucial role in promoting the degradation of tannin (antinutrient) and phenolic compounds. Xylanase continued to release flavonoids while microbial metabolism consumed them with the extension of SSF time. SSF is an effective way to improve the bioactivity and processing characteristics of SG. © 2024 Society of Chemical Industry.

Pasta waste has previously been studied in a process to obtain lactic acid through a sequential hydrolysis and fermentation. The process was improved by using enzymes produced via solid-state fermentation of wheat bran in shake flasks. However, the scale-up of the solid-state fermentation is a complex task. In this study, amylase was produced in a home-designed tray bioreactor which allowed to carry out the hydrolysis and fermentation steps at the pilot scale. Due to the efficiency of the solid-state fermentation and the activity of the enzyme, only a small amount (100 g) of wheat bran was required to achieve high yields in a hydrolysis in a 72 L bioreactor (50 L working volume). Overall, the lactic acid yield was 0.68 gLA/gdS, and after the purification, the lactic acid recovered was 55 %, with a total ion concentration of 500 mg/L and an enantiomeric purity of 98.1 % L-LA.

The investigation of transient multidimensional heat transfer in solid state fermentation