Showing papers on "Solid-state fermentation published in 2020"

From stale bread and brewers spent grain to a new food source using edible filamentous fungi.

Abstract: By-products from the food sector with a high load of organic matter present both a waste-handling problem related to expenses and to the environment, yet also an opportunity. This study aims to increase the value of stale bread and brewers spent grain (BSG) by re-introducing these residues to the food production chain by converting them to new protein-enriched products using the edible filamentous fungi Neurospora intermedia and Rhizopusoryzae. After 6 days of solid state fermentation (at 35°C, with a95% relative humidity and moisture content of 40% in the substrate) on stale bread, a nutrient-rich fungal-fermented product was produced. The total protein content, as analyzed by total amino acids, increased from 16.5% in stale sourdough bread to 21.1% (on dry weight basis) in the final product with an improved relative ratio of essential amino acids. An increase in dietary fiber, minerals (Cu, Fe, Zn) and vitamin E, as well as an addition of vitamin D2 (0.89 µg/g dry weight sample) was obtained compared with untreated stale bread. Furthermore, addition of BSG to the sourdough bread with the aim to improve textural changes after fermentation showed promising outcomes. Cultivation of N. intermedia or R. oryzae on stale sourdough bread mixed with 6.5% or 11.8% BSG, respectively, resulted in fungal-fermented products with similar textural properties to a commercial soybean burger. Bioconversion of stale bread and BSG by fungal solid state fermentation to produce a nutrient-enriched food product was confirmed to be a successful way to minimize food waste and protein shortage.

Effect of solid-state fermentation with Lactobacillus casei on the nutritional value, isoflavones, phenolic acids and antioxidant activity of whole soybean flour

Abstract: This work researched the effect of solid-state fermentation (SSF) with Lactobacillus casei on the changes of nutritional components, isoflavones, phenolic acids and antioxidant activity of whole soybean flour (WSF). Results showed that total protein, vitamin B1, vitamin B2, and β-carotene of WSF increased after fermentation. Fermented whole soybean flour (FWSF) showed higher essential amino acids contents and essential amino acid index. There was no significant change in ash, Fe, Ca, Zn, and K content (P > 0.05). SSF treatment caused a significant decrease in lipids, crude fibre, and antinutritional factors (lipoxygenase-1, lipoxygenase-3, trypsin inhibitor, and urease) (P

Enhanced nutritional value of chickpea protein concentrate by dry separation and solid state fermentation

Abstract: A sustainable dry processing method to obtain nutritional and functional chickpea products was developed, yielding protein concentrates suited to prepare products without additives. Chickpeas were milled and air-classified into protein and starch-enriched concentrates. Subsequently, spontaneous solid state fermentation (SSF) with daily back-slopping was performed at 37 °C. The dominant autochthonous lactic acid bacteria (LAB) strains in chickpea flour and enriched fractions were Pediococcus pentosaceus and Pediococcus acidilactici. Strains were selected on their ability to metabolise flatulence-causing α-galactosides. SSF reduced the pH of the doughs in 24h from 6.6 to 4.2. After 72 h, concentrations of raffinose and stachyose were reduced by 88.3–99.1%, while verbascose became undetectable. Moreover, phytic acid reduced with 17% while total phenolic contents increased with 119%. Besides the observed differences in smell, texture and colour, the sourdoughs showed 67% higher water-holding capacity. This natural route to produce chickpea concentrates thus increases both the nutritive and technical functionality. Industrial relevance Increasing the sustainability of our food production is required to meet the demand for food of our growing world population. A processing route combining dry fractionation and solid state fermentation is developed to prepare chickpea concentrates with improved nutritional properties. This route is more sustainable as the use of water and thus energy-intensive drying steps are minimised. Moreover, it provides more natural ‘clean-label’ foods, i.e., foods with less additives and minimally processed. Solid state fermentation is used to reduce the presence of anti-nutritional factors, i.e., α-galactosides and phytic acid. Autochthonous LAB were accumulated via back-slopping and employed as starter culture as an alternative to the use of a commercial starter culture. Chickpea sourdoughs with enhanced nutritional quality of chickpea were obtained. The sourdough may be used directly to fortify cereal products like chickpea protein enriched bread or can be dried into a chickpea ingredient for many other applications as well.

Pomegranate peel waste: a new substrate for citric acid production by Aspergillus niger in solid-state fermentation under non-aseptic conditions

Abstract: Citric acid production from dried and non-dried pomegranate peel wastes by the fungus Aspergillus niger B60 in solid-state fermentation (SSF) under non-aseptic conditions was investigated. The maximum amount of citric acid (278.5 g/kg dry peel) was achieved using dried (at 45 °C for 48 h) pulverized pomegranate peels with moisture content 75% and initial pH 8.0, after 8 days of fermentation at 25 °C. Under the same fermentation conditions, a higher amount of citric acid (306.8 g/kg dry peel) was observed during SSF of non-dried peels as a substrate. The addition of methanol as an inducer at a concentration of 3% (w/w) into the dried and non-dried pomegranate peel wastes increased the amount of citric acid to 300.7 and 351.5 g/kg dry peel, respectively. The non-dried pomegranate peel waste in SSF under non-aseptic conditions is a cheap and useful substrate for the commercial production of citric acid with low energy cost. The utilization of inexpensive agro-industrial wastes through SSF can contribute to achieve industrially feasible and environmentally sustainable bio-production of citric acid.

Production of bioactive peptides from corn gluten meal by solid-state fermentation with Bacillus subtilis MTCC5480 and evaluation of its antioxidant capacity in vivo

Abstract: Production of bioactive peptides from corn gluten meal (CGM) by solid-state fermentation (SSF) with Bacillus subtilis MTCC5480 (BS5480) and the antioxidant capacity in vivo were investigated in the present study. During the SSF process, CGM peptides (CGMP) production reached a maximum (369.4 mg/gdp) when the fermentation conditions were as follows: temperature, 36 °C; initial pH, 6.0; moisture, 46%; inoculation size, 5.8 × 109 spores/g; time, 5 d; peptone, 5 mg/g; and glucose, 10.7 mg/g. In addition, the d -galactose-induced aging rats fed CGMP (molecular weight

Solid-state fermentation with probiotics and mixed yeast on properties of okara

Abstract: The effect of solid-state fermentation with compound probiotics and two types of yeast (Saccharomyces cerevisiae and Hansenula sp.) on the composition and selected quality attributes of okara were studied. Four different fermentation schemes, i.e., compound probiotics fermentation (P), mixed yeast (Saccharomyces cerevisiae and Hansenula sp.) fermentation (SH), co-fermentation of compound probiotics and mixed yeast (P + SH) and two-stage fermentation of compound probiotics and mixed yeast (P-SH) were comparatively assessed for their proximate composition, abilities to improve selected physicochemical, antioxidant, functional properties and sensory attributes (flavor and taste) of okara. The results showed that all the fermentation schemes could significantly improve the proximate composition, physicochemical as well as antioxidant activities and sensory attributes of okara. The bitterness and astringency of the okara were also reduced. The P-SH samples contained crude fiber of 12.0 g/100 g dry sample, total phenols of 154 mg gallic acid equivalence/100 g dry sample, free amino acids of 3.80 g/100 g dry sample. The DPPH free radical scavenging capacity and ABTS free radical scavenging capacity of the P-SH samples were 776 mg Trolox equivalence/100 g dry sample and 487 mg Trolox equivalence/100 g dry sample, respectively. The P + SH sample produced more alcohol, ester and other important flavoring substances than the other three methods. However, the P + SH sample had a relatively acidic taste.

Solid-state fermentation of canola meal with Aspergillus sojae, Aspergillus ficuum and their co-cultures: Effects on physicochemical, microbiological and functional properties

Abstract: Effects of solid-state fermentation (SSF) with Aspergillus sojae, Aspergillus ficuum and their co-cultures on physicochemical, microbiological and functional properties of canola meal (CM) were investigated. Fibre fractions, in vitro enzyme protein digestion, protein molecular distribution and colour attributes were also evaluated. Samples did not differ in their proximate composition except in soluble carbohydrate (glucose) and starch. The microbiological counts of the fermented meals were higher than that of the unfermented CM. Phytic acid content and total glucosinolates reduced (p

Solid‐state fermentation of lentil (Lens culinaris L.) with Aspergillus awamori: Effect on phenolic compounds, mineral content, and their bioavailability

Abstract: Microorganisms have long been used in the production of a variety of foods, alcoholic beverages, additives, and supplements due to their cost effectiveness and environmental advantages. Solid‐state fermentation (SSF) reproduces the natural microbiological process that can be utilized in a controlled way to produce the desired product. In the present study, modulation of phenolic compounds, antioxidant potential, and mineral content during SSF of three lentil cultivars, namely, HM‐1, LL‐931, and Sapna, were explored. The total phenolic content (TPC) for 6th day Aspergillus‐fermented lentil (AFL) flour increased by 79.2% for cv. HM‐1, 78.8% for cv. LL‐931, and 122.8% for cv. Sapna. High‐performance liquid chromatography (HPLC) results also showed that SSF not only improved the phenolic content of lentil cultivars but also resulted in the formation of some new phenolic compounds (resorcinol and cinnamic acid). The condensed tannin content, DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) inhibition activity, hydroxyl free radical scavenging activity, reducing power activity, and total antioxidant capacity of aqueous ethanolic extracts from all AFLs also increased significantly (p ≤ 0.05) up to 6th day of fermentation. Mineral content differed significantly (p ≤ 0.05), with AFL extracts exhibiting higher mineral content than their unfermented counterparts. Among different minerals, Cu content of all AFL extracts was the highest with an increase of 46.4% to 60.0% upon fermentation. All minerals showed a significant (p ≤ 0.05) increase in their concentrations upon fermentation except for K in which the increase was less than 0.1%. However, in vitro bioavailability of iron and zinc was significantly (p ≤ 0.05) higher in AFL as compared with their unfermented counterparts, with the highest level being observed on the 6th day of fermentation. Thus, biotransformed lentils could be utilized in the preparation of functional foods and novel nutraceuticals for their health‐promoting properties.

Physicochemical Factors Affecting Microbiota Dynamics During Traditional Solid-State Fermentation of Chinese Strong-Flavor Baijiu.

Abstract: Spontaneous solid-state fermentation (SSF) of Chinese Baijiu involves diverse microbes from Daqu and pit mud (PM). Given that the transfer of interphase microflora during the fermentation is a continuous and dynamic process, longitudinal studies are essential to provide ecological insights into community stability and response to consecutive disturbances in the process. In this context, this study aimed to generate a comprehensive longitudinal characterization of the microbiota during the fermentation processes of Chinese strong-flavor Baijiu (CSFB) differing in cellar ages with consideration for potential relation to physicochemical variables. The microecology variations observed during the 6-years cellar SSF (SCSSF) and 30-years cellar SSF (TCSSF) processes reveal that fungal composition contributes to a larger extent than bacterial composition to such variations. Orders of Lactobacillales, Anaerolineales, Enterobacteriales, Bacillales, Eurotiales, and Saccharomycetales dominated (average relative abundances >10%) the microbiota in both SCSSF and TCSSF processes but with a different percentage in the operational taxonomic unit (out) abundances. Compared with the SCSSF process, TCSSF possessed slower microbial succession rates, which were in accordance with the profile of physicochemical properties. From a network perspective, the microbial community structure observed in the TCSSF processes was more stable than that in the SCSSF. This may benefit from the milder physicochemical conditions of the TCSSF processes, especially the temperature, which is also more beneficial to the growth of some groups that have negative effects on fermentation, such as Staphylococcus, Pseudomonas, and Acinetobacter.

The effects of solid-state fermentation on the content, composition and in vitro antioxidant activity of flavonoids from dandelion

Abstract: Dandelion (Taraxacum officinale), a common plant worldwide, is used as both a medicine and food. Fermentation is a food processing technology that has many advantages, such as low energy cost, changes in product characteristics, and enhanced product quality. The purpose of this study was to investigate the effect of solid-state fermentation (SSF) on the content, composition and antioxidant activity of dandelion flavonoids. Response surface methodology was used to optimize dandelion fermentation conditions. Under optimized conditions, the maximum flavone concentration was 66.05 ± 1.89 mg/g. The flavonoid content of the crude extract from fermented dandelion (FDF) was 183.72 ± 2.24 mg/g. The flavonoid compounds in the crude extracts were further identified by UPLC-ESI-MS/MS. A total of 229 flavonoid compounds were identified, and 57 differential flavonoids (including 27 upregulated and 30 downregulated flavonoids) between FDF and the crude extract of unfermented dandelion (DF) were observed, of which 25 were annotated to metabolic pathways. FDF displayed superior antioxidant activity to that of DF in in vitro DPPH radical-scavenging and reducing power assays. The favorable results of our investigation could provide a new way for the exploitation and utilization of dandelion, which could be promising for its application as an antioxidant and functional food additive with flavonoids as ingredients.

Optimization of the solid-state fermentation conditions and characterization of xylanase produced by Penicillium roqueforti ATCC 10110 using yellow mombin residue (Spondias mombin L.)

Abstract: Yellow mombin residue was investigated as a substrate for the production of xylanase by Penicillium roqueforti ATCC 10110 in solid-state fermentation. The parameters incubation temperature, initial...

Production and characterization of a novel alkaline protease from a newly isolated Neurospora crassa through solid-state fermentation

Abstract: Microbial proteases are widely used to prepare protein hydrolysates with health-promoting biopeptides. Here, a newly isolated strain of Neurospora crassa (named as CGMCC3088) was used to produce proteases through solid-state fermentation of okara as the substrate. The optimal fermentation conditions are: okara, 10 g; water, 21 mL; initial pH, 5.0; incubation temperature, 30 °C; inoculation amount, 2 mL; fermentation time, 72 h, with a corresponding protease activity of 1959.82 U/g. The protease was further purified by ammonium sulphate precipitation, followed by ion-exchange chromatography on DEAE-Sepharose and Sephadex G-75. The molecular weight of the protease was 30 kDa, and further mass spectrometry analysis clearly indicated that it was a novel protease. The protease had the optimal activity at 55 °C and pH 9. The enzyme activity was partially inhibited by SDS and metal ions, whereas little affected by organic solvents. The protease was completely inactivated by phenylmethylsulfonyl fluoride, indicating its dominant serine protease activity. The enzyme preferably hydrolyzed casein, and kinetic analysis showed that its Km and Vmax were 2.18 mg/mL and 36.36 μg/mL/min, respectively. Therefore, Neurospora crassa CGMCC3088 has the potential to produce a novel organic solvent-stable alkaline protease, which may be applied to the preparation of bioactive ingredients.

Enhanced Production of Biosurfactant from Bacillus subtilis Strain Al-Dhabi-130 under Solid-State Fermentation Using Date Molasses from Saudi Arabia for Bioremediation of Crude-Oil-Contaminated Soils.

Abstract: Crude oil and its derivatives are the most important pollutants in natural environments. Bioremediation of crude oil using bacteria has emerged as a green cleanup approach in recent years. In this study, biosurfactant-producing Bacillus subtilis strain Al-Dhabi-130 was isolated from the marine soil sediment. This organism was cultured in solid-state fermentation using agro-residues to produce cost-effective biosurfactants for the bioremediation of crude-oil contaminated environments. Date molasses improved biosurfactant production and were used for further optimization studies. The traditional "one-variable-at-a-time approach", "two-level full factorial designs", and a response surface methodology were used to optimize the concentrations of date molasses and nutrient supplements for surfactant production. The optimum bioprocess conditions were 79.3% (v/w) moisture, 34 h incubation period, and 8.3% (v/v) glucose in date molasses. To validate the quadratic model, the production of biosurfactant was performed in triplicate experiments, with yields of 74 mg/g substrate. These findings support the applications of date molasses for the production of biosurfactants by B. subtilis strain Al-Dhabi-130. Analytical experiments revealed that the bacterial strain degraded various aromatic hydrocarbons and n-alkanes within two weeks of culture with 1% crude oil. The crude biosurfactant produced by the B. subtilis strain Al-Dhabi-130 desorbed 89% of applied crude oil from the soil sample. To conclude, biosurfactant-producing bacterial strains can increase emulsification of crude oil and support the degradation of crude oil.

Dynamics of the Physicochemical Characteristics, Microbiota, and Metabolic Functions of Soybean Meal and Corn Mixed Substrates during Two-Stage Solid-State Fermentation.

Abstract: Substantial annual economic loss in livestock production is caused by antinutritional factors in soybean meal and corn mixed substrates, which can be degraded by microbial fermentation. Although considerable efforts have been made to explain the effects of fermentation on soybean meal and corn-based feed, the dynamics of the physicochemical characteristics, microbiota, and metabolic functions of soybean meal and corn mixed substrates during solid-state fermentation remain unclear. Here, multiple physicochemical analyses combined with high-throughput sequencing were performed to reveal the dynamic changes that occur during a novel two-stage solid-state fermentation process. Generally, inoculated bacteria rapidly proliferated in the initial 12-h aerobic fermentation (P = 0.002). Notably, most nutritional changes occurred during 12 to 24 h compared to 0 to 12 h. Second-stage anaerobic fermentation increased the bacterial abundance and lactic acid content (P IMPORTANCE Solid-state fermentation (SSF) plays pivotal roles not only in human food but also farm animal diets. Soybean meal (SBM) and corn account for approximately 70% of the global feed consumption. However, the nutritional value of conventional SBM and corn mixed substrates (MS) is limited by antinutritional factors, causing substantial economic loss in livestock production. Although emerging studies have reported that SSF can improve the nutritional value of SBM-based substrates, the dynamic changes in the physicochemical features, microbiota, and metabolic functions of MS during SSF remain poorly understood, limiting further investigation. To provide insights into the dynamics of the physicochemical characteristics and the complex microbiome during the two-stage SSF of MS, multiple physicochemical analyses combined with high-throughput sequencing were applied here. These novel insights shed light on the complex changes that occur in the nutrition and microbiome during two-stage SSF of MS and are of great value for industrial feed-based practices and metabolomic research on SSF ecosystems.

Optimised cellulase production from fungal co-culture of Trichoderma reesei NCIM 1186 and Penicillium citrinum NCIM 768 under solid state fermentation

Abstract: Microbial cellulases find applications in many industries and constitute a significant share of the world’s industrial enzyme market. In order to improve the cost function of the cellulose producing processes with enhanced yield and novel activities, superior bioprocesses are formulated these days. Intending to produce higher titre of cellulase enzyme, present study deals with fungal co-culture and to investigate its feasibility of producing higher cellulase titre via solid state fermentation (SSF). Various process parameters were optimized for induced cellulase production from the co-culture of Trichoderma reesei NCIM 1186 and Penicillium citrinum NCIM 768 in SSF. Among different low cost and easily available agricultural lignocellulosic waste, wheat bran was found to be the most suitable substrate. The highest cellulase yield of 6.71 FPU/gds is obtained on 6th day of fermentation using steam pre-treated wheat bran with 70 % moisture content when inoculated with 106 spores of mixed suspension at 30 °C and pH 5. A further possibility to use whole fermented matter for saccharification instead of extracted cellulase was also investigated with the aim of abolishing an extraction step. Akin sugar yield of 6.45 mg/mL and 6.58 mg/mL was obtained at 72 h of hydrolysis of steam pre-treated wheat bran, using cellulase extract and whole fermented matter, respectively. Fungal co-culture of T. reesei and P. citrinum in SSF results in the highest cellulase titre using low cost agricultural waste as a substrate, which can be further used for successful saccharification in the form of whole fermented matter or as extracted enzyme.

Fungal detoxification of coffee pulp by solid-state fermentation

Abstract: Biotechnological advances offer potential opportunities for economic utilization of agro-industrial residues such as coffee pulp. Coffee pulp is a fibrous and mucilaginous residual material obtained during the processing of coffee cherries by the wet or dry process. The coffee pulp contains some amount of caffeine and tannins, which makes it toxic in nature, resulting in the disposal problem, however, the coffee pulp is characterized by its nutritional high-value. To increase the use of the coffee pulp (Arabica or Robusta) in animal feed, these compounds were removed by biodetoxification through solid-state fermentation using Rhizopus oryzae (MUCL 28,168). Temperature, moisture, and inoculum size were those studied parameters that had a significant influence on the decrement of the antiphysiological compounds. It was found that the highest decrease of caffeine (52%) and condensed tannins (52%) was achieved at pH 6.0, temperature 30 °C, initial moisture 70%, and inoculum 1 × 106 spores/g. The results show that with this process a reduction of these compounds can be achieved, allowing efficient use of the coffee pulp in different industries.

Solid-state fermentation for single-cell protein enrichment of guava and cashew by-products and inclusion on cereal bars

Abstract: Food byproducts derived from industrial processing present high potential to be reused as ingredients for human nutrition. However, even though food byproducts are often reprocessed and studied, few studies report the inclusion of such byproducts on new food products and assess the new product acceptability. Therefore, on our work guava peels and cashew bagasse were subjected to solid-state fermentation for protein enrichment through single-cell protein and then included on cereal bars for human nutrition. The solid-state fermentation of fruit byproducts was carried out at 30 °C, with 70% equilibrium humidity, 0.9 water activity, and initial Saccharomyces cerevisiae yeast concentration of 3% for the cashew bagasse and 5% for the guava peels. The protein-enriched byproducts were included on three different formulations of cereal bars, and physicochemical, instrumental texture, and sensorial analysis was performed. Multivariate analysis was used to investigate the results. Solid-state fermentation resulted in increased 11 times the protein content of both byproducts. Instrumental texture revealed that high dietary fiber content increases hardness and cohesiveness. All cereal bars presented average scores of 7/10 for sensorial attributes and average 4/5 for purchase intention. During the storage period the cereal bars presented increases in the textural parameters when compared to the control bars. However, all samples revealed compositional stability during the 28-day test period. The overall results suggest that the addition of protein-enriched byproducts is an alternative to add nutritional and economic value to cereal bars.