Effect Of Spontaneous Fermentation Research Articles

Effects of spontaneous fermentation on microbial succession and its correlation with volatile compounds during fermentation of Petit Verdot wine

Petit Verdot is widely used in blend wines but only few studies focus on the effect of microorganisms on the aroma formation of its monovarietal wine. This study explored the correlation between microorganisms and aromas during spontaneous fermentation (SF) and inoculated fermentation (IF). The changes of volatile compounds and microbial succession during the wine fermentation were monitored by HS-SPME-GC-MS and HTS. The results showed that SF resulted wines with more aromatic and regional characteristics because of significantly higher content and varieties of higher alcohols, acetate esters and C6 compounds, thus highlighting the ‘floral’ and ‘fruity’ characteristics of Petit Verdot wine. The PCA and OPLS-DA showed that there were significant differences in aromas and microorganisms under SF, and IF, while correlations between them were established by OPLS and Spearman (VIP >1, P < 0.05). Among them, four unique core bacteria in SF were positively correlated (P < 0.05) with four important higher alcohols and most of the esters. Non-Saccharomyces in SF were positively correlated (P < 0.01) with C6 compounds. Therefore, SF had a potential application prospect for improving wine flavor and provided a reference for further understanding the role of microorganisms in the formation of aroma compounds.

Phenolics and color components of young Cabernet Sauvignon wines: effect of spontaneous fermentation and bottle storage

Phenolics and color components of young Cabernet Sauvignon wines: effect of spontaneous fermentation and bottle storage

HPTLC and ATR/FTIR Characterization of Antioxidants in Different Rosemary Extracts.

The effect of spontaneous fermentation by lactic acid bacteria on the extraction yield of bioactive compounds and antioxidant activity from rosemary leaf extracts was investigated using high-performance thin-layer chromatography (HPTLC). Brining and spontaneous fermentation with lactic acid bacteria more than doubled extraction of polyphenolics and antioxidants from the rosemary leaves. The results show that lactic acid fermentation enhances antioxidant activity in extracts by increasing the total phenolic content but does not increase extraction of phytosterols. Increased extraction of phenolic oxidants during fermentation assisted extraction, results from the in situ generated natural eutectic solvent from the plant sample. ATR-FTIR spectra from the bioactive bands suggests that this increased antioxidant activity is associated with increased extraction of rosmarinic acid, depolymerised lignin, abietane diterpenoids and 15-hydroxy-7-oxodehydroabietic acid.

Effects of spontaneous fermentation on the microorganisms diversity and volatile compounds during ‘Marselan’ from grape to wine

‘Marselan’ is a promising wine grapevine with unique qualities, studies on its introduction and characteristics have never stopped. However, little is known about the fermentation process of ‘Marselan’ wine. In this study, we compared industrial-scale spontaneous (SMF) and inoculated (IMF) fermentation processes on the succession of microbial community and the change in volatile compounds and predicted their correlations. SMF could ferment ‘Marselan’ to dry red wine with alcohol content of 13.37% ± 0.76% (v/v) in 10 days and enhance the total concentration and odour activity values (OAVs) of volatile compounds. Ethyl caprylate, ethyl caprate, ethyl caproate and citronellol (OAVs > 1.0) were important volatile compounds in SMF and IMF wines. Compared with IMF, SMF was more outstanding in initial non-Saccharomyces diversity, including Hanseniaspora, Metschnikowia and Issatchenkia. In addition, Spearman's correlation (|ρ| > 0.7) and bidirectional orthogonal partial least squares (O2PLS, VIP > 1.0) analysis showed that some indigenous microorganisms in grape were closely related to the formation of volatile compounds, such as lactic acid bacteria, non-Saccharomyces and Saccharomyces cerevisiae. Overall, results showed that SMF could strengthen the flavour of ‘Marselan’ wine, and the possibility of consideration screening indigenous aroma-producing microorganisms as starter to improve the unique characteristics of ‘Marselan’ wine.

Bioactive compounds, antioxidant activity and consumer acceptability of porridges of finger millet (Eleusine coracana) flours: effects of spontaneous fermentation

ABSTRACT The flours of finger millet (Eleusine coracana) from light brown and dark brown varieties fermented spontaneously for 96 h were evaluated for their bioactive compounds, antioxidant activity and physicochemical properties. The consumer acceptability of the fermented porridges was also determined. Bioactive compounds of finger millet (FM) flours significantly (p < .05) increased with fermentation time, total polyphenolic content increased from 166 to 488 mg/100 g (light brown) and 420 to 606 mg/100 g (dark brown) and total flavonoid content increased from 160 to 330 mg/100 g (light brown) and 249 to 465 mg/g (dark brown). However, the total anthocyanin content of FM flours decreased with fermentation time. The DPPH activity of FM flours significantly (p < .05) increased with fermentation time from 52 to 58% (light brown), 53 to 59% (dark brown) and inhibitory effect on lipid peroxides significantly (p < .05) increased from 0.9 to 1.3% (dark brown) and 1.7 to 4.5% (dark brown). Fermentation significantly increased the crude protein of FM flours (light brown, 7.12 to 9.43%) and (7.80 to 9.53%, dark brown). Dietary fiber, fats, moisture and carbohydrates significantly (p < .05) decreased. Total titratable acid significantly (p < .05) increased from 0.49 to 1.77 g/100 g (light brown) and 0.47 to 1.58 g/100 g (dark brown). Fermentation resulted in the decrease of FM flours pH values. However, the total soluble solids were significantly (p < .05) different in both flours. Fermentation caused the lightness (L*) and redness (a*) to decrease and the yellowness (b*) of both flours to increase with time. The textural properties of the FM porridges decreased with fermentation time. The FM flours of both varieties which were fermented for 24 h resulted in porridges with the best sensory attributes. The results suggest that spontaneous fermentation could be an effective way of improving the bioactive compounds and antioxidant activity of FM flours.

Effects of spontaneous fermentation on Karalahna and Cabernet Sauvignon young red wines: volatile compounds, sensory profiles and identification of autochthonous yeasts

The purposes of the present study were to evaluate the volatile compounds and sensory characteristics of young red wines produced by spontaneous and inoculated fermentations of Karalahna (KL) and Cabernet Sauvignon (CS) grapes and to identify the yeasts responsible for spontaneous fermentation by molecular methods. A total of 28 volatile compounds in KL wines and 35 compounds in CS wines were identified and quantified by GC–MS. The concentration of higher alcohols and esters differed significantly among spontaneously fermented and inoculated wines. Spontaneous fermentation resulted in greater amount of higher alcohols in KL wines, while inoculated wines had greater amount of higher alcohols in CS wines. Spontaneously fermented KL and CS wines showed greater amounts of esters than inoculated wines. KL wines obtained by spontaneous fermentation had significantly higher scores than inoculated wines based on fruity and green aromas, body and overall impression. Spontaneously fermented CS wines were found significantly higher in fruity and floral aromas than inoculated wines.

Spontaneous fermentation tunes the physicochemical properties of sweet potato starch by modifying the structure of starch molecules

The effects of spontaneous fermentation on the molecular and physicochemical characteristics of sweet potato starch stored in tank during twelve months were investigated. From starch slurry collected during spontaneous fermentation, eight isolates showed amylolytic activity, which included two Acetobacter strains, five Bacillus strains and one Gluconacetobacter strain. By spontaneous fermentation, the amylose content and the average molecular weight of starch were significantly decreased. Besides, the native and fermented starches showed different amylopectin chain-length distribution patterns. Among them, no significant differences in granular morphology, granule size distribution, and crystalline structure. However, the thermal and pasting properties as well as the hardness of the starch gel differed significantly. Pearson's correlation analysis showed that the physicochemical properties was mainly influenced by the changes in the amylose content, amylopectin chain-length distribution as well as the average molecular weight of starch. These findings demonstrated the feasibility of spontaneous fermentation as a tool for modifying starches.

Complementary feeding and effect of spontaneous fermentation on anti-nutritional factors of selected cereal-based complementary foods

BackgroundMalnutrition has been responsible directly or indirectly for 10.9 million deaths worldwide annually among children under five. Childhood malnutrition is highly related to poor nutritional quality diet in developing countries where there is limited access to animal based foods. Most foods consumed by young children are cereal based which contain high amounts of anti-nutritional factors. Fermentation is thought to significantly lower the content of anti-nutrients in cereal grains. This study therefore, aimed to determine complementary feeding practices and effect of spontaneous fermentation on anti-nutritional factors and mineral contents of selected cereals.MethodsCross sectional survey was conducted in Ebinat district to determine complementary feeding practices among 324 lactating mothers. Laboratory analysis was carried out for teff and wheat cereal grains to determine the effect of spontaneous fermentation on anti-nutrients as well as mineral contents.ResultsPrevalence of appropriate complementary feeding practice was 1.5%. Fermentation of the sampled cereals for 12 h significantly (p < 0.05) reduced total phytate and total tannin. The reduction continued and most of the reduction of phytate and tannin contents occurred during the 72 h of fermentation for both cereal samples. However, the reduction for some fermentation times was not statistically significant. A significant (p < 0.05) variation was also noticed in the total amounts of calcium, iron and zinc in both sampled cereals within the 72 h of fermentation.ConclusionPrevalence of appropriate complementary feeding practice was very low. There were significant reductions of phytate and tannin contents with concomitant increments of minerals after fermentation of cereals. Phytate: mineral ratios were significantly decreased after fermentation for all the parameters examined. It is recommended to ferment cereals while preparing complementary foods for children so as to enhance their micronutrient uptake.

Effect of spontaneous fermentation and amylase-rich flour on the nutritive value, functional and viscoelastic properties of cowpea-fortified nixtamalized maize

Studies were conducted to evaluate the combined effects of spontaneous fermentation and amylase-rich flours (ARF) on some nutritive value, functional and viscoelastic properties of cowpea-fortified nixtamalized maize. A 2 × 3 × 3 factorial design, with fermentation medium, fermentation time and ARF level, was performed. The blends were fermented for the specific times and analysed for their titratable acidity, pH, water absorption capacity, viscoelastic properties, texture, protein and mineral content. Fermentation and ARF addition influenced titratable acidity, pH, water absorption, viscoelastic properties and texture of the cowpea-fortified nixtamalized maize. Addition of ARF decreased the viscoelastic properties, texture and pH of all the blends with a corresponding increase in acidity. Slight increases in protein and ash contents were noted with products fermented in coconut water, but ARF addition had only a marginal effect. Thus, fermentation and ARF addition could be applied to cowpea-fortified nixtamalized maize to enhance the functionalities with reduced viscosity and texture suitable for weaning food formulations.

Volatiles of orange juice and orange wines using spontaneous and inoculated fermentations

The effect of spontaneous fermentation and inoculated fermentation on the volatile compounds of orange wine was studied. The differences on volatile compounds of orange juice and orange wine were also observed. The volatile compounds were analyzed by sensory and instrumental analysis. Solid phase microextraction was used for extraction of volatile compounds. Sensory analysis indicated that no significant differences existed on the wine odor between the two methods. A total of 17 and 19 volatile compounds were identified and quantified in spontaneous and inoculated fermentations, respectively. Esters followed by alcohols and terpenes were the most abundant volatile compounds in the two orange wines. Thirteen of these compounds were present both in the two methods. Totally 31 volatile compounds were found in orange juice, and terpenes were quantitatively the dominant group. Esters were found to be the important volatile compounds formed during fermentation, such as isoamyl acetate, ethyl hexanoate, ethyl benzoate, diethyl succinate, ethyl decanoate and ethyl laurate, etc.

Effect of spontaneous fermentation on the physical properties of corn starch and rheological characteristics of corn starch noodle

Starch was isolated from spontaneously fermented corn to study the effect of fermentation on the physical properties of corn starch and the suitability of fermented corn for starch noodle. Considering the security of fermentation, aflatoxin B 1 content in fermented samples was also tested. Results showed that above 75 °C, fermented samples had significantly lower swelling power and solubility than control samples ( p < 0.05). The peak viscosity and breakdown initially increased and then decreased, while final viscosity and setback decreased gradually with fermentation time. Fermented samples had significantly higher gel strength ( p < 0.05) and noodles from them had higher maximum tensile stress, maximum tensile strain and work to break the noodle. Results of sensory evaluation indicated that fermentation significantly improved quality of corn starch noodle, and quality of starch noodle from corn fermented for 19 days was comparable to mung bean starch noodle. The spontaneous fermentation was safe based on the results of toxin test.

Effect of Spontaneous Fermentation on the Chemical Composition of Thermally Treated Jack Beans (Canavalia ensiformis L.)

Effect of Spontaneous Fermentation on the Chemical Composition of Thermally Treated Jack Beans (Canavalia ensiformis L.)

Fate of aflatoxin B1 during fermentation of maize into \"ogi\"

The fate of aflatoxins in fermented maize (Ogi) was investigated. The effect of spontaneous fermentation and storage under refrigeration temperature (4°C) and ambient tropical condition (28°C) was studied. Levels as high as 50µg/kg was recorded for the control sample. Aflatoxins present in the maize grains persisted after 24 to 48 hours period of fermentation. However, there was a 50% reduction after 72 hours of fermentation of maize (50µg kg-1 to 25µg kg1) which was statistically significant at p