Fermentation Of Potato Research Articles

Natural fermentation of potato (Solanum tuberosum L.) starch: Effect of cultivar, amylose content, and drying method on expansion, chemical and morphological properties

Natural fermentation with sun-drying is a modification that promotes the expansion capacity of starch, and its effects on potato starch have not been reported so far. The aim of this study was to evaluate the effects of the amylose content of potato (Solanum tuberosum L.) starches and natural fermentation followed by oven or sun drying on its properties. Cassava starch was also used a control. Native and fermented starches were evaluated based on their chemical composition, amylose, carboxyl and carbonyl content as well as their thermal, pasty, and morphological properties. The fermentation water was evaluated by pH and titratable acidity to control the process. Puffed balls were prepared to evaluate expandability, mass loss, porosity and texture. The fermentation intensity was greater for potato and cassava starch with low-amylose content than for potato starch with higher amylose content. In addition, the acidity of the fermentation water increased faster with cassava starch than with potato starches. The fermented potato starches with the highest amylose content had low acidity and low expansion capacity compared to the fermented potato and cassava starches with low-amylose content. Fermentation and sun-drying of low-amylose potato and cassava starches increased the expansion and reduced the hardness of the puffed balls.

Effects of different strains fermentation on nutritional functional components and flavor compounds of sweet potato slurry.

In this paper, we study the effect of microbial fermentation on the nutrient composition and flavor of sweet potato slurry, different strains of Aspergillus niger, Saccharomyces cerevisiae, Lactobacillus plantarum, Bacillus coagulans, Bacillus subtilis, Lactobacillus acidophilus, and Bifidobacterium brevis were employed to ferment sweet potato slurry. After 48 h of fermentation with different strains (10% inoculation amount), we compared the effects of several strains on the nutritional and functional constituents (protein, soluble dietary fiber, organic acid, soluble sugar, total polyphenol, free amino acid, and sensory characteristics). The results demonstrated that the total sugar level of sweet potato slurry fell significantly after fermentation by various strains, indicating that these strains can utilize the nutritious components of sweet potato slurry for fermentation. The slurry's total protein and phenol concentrations increased significantly, and many strains demonstrated excellent fermentation performance. The pH of the slurry dropped from 6.78 to 3.28 to 5.95 after fermentation. The fermentation broth contained 17 free amino acids, and the change in free amino acid content is closely correlated with the flavor of the sweet potato fermentation slurry. The gas chromatography-mass spectrometry results reveal that microbial fermentation can effectively increase the kinds and concentration of flavor components in sweet potato slurry, enhancing its flavor and flavor profile. The results demonstrated that Aspergillus niger fermentation of sweet potato slurry might greatly enhance protein and total phenolic content, which is crucial in enhancing nutrition. However, Bacillus coagulans fermentation can enhance the concentration of free amino acids in sweet potato slurry by 64.83%, with a significant rise in fresh and sweet amino acids. After fermentation by Bacillus coagulans, the concentration of lactic acid and volatile flavor substances also achieved its highest level, which can considerably enhance its flavor. The above results showed that Aspergillus niger and Bacillus coagulans could be the ideal strains for sweet potato slurry fermentation.

Response of Native Chickens (3-10 Weeks) Fed on Diets Substituated With Graded Levels of Sweet Potato Fermentation

The purpose of this study was to determine the effect of giving fermented sweet potato waste in the ration on the appearance of native chickens aged 3 - 10 weeks and to find out what percentage of the level of use of fermented sweet potato waste in the ration. This study used a completely randomized design (CRD) with 5 treatments and 3 replications. The treatments consisted of: R0 = ration without additional fermented sweet potato waste as control, R1 = ration containing 3% unfermented sweet potato was, R2 = ration containing 3% fermented sweet potato waste, R3 = ration containing 6% fermented sweet potato waste, R4 = The ration contains 9% fermented sweet potato waste. Each replication (experimental unit) used 5 native chickens so that the number of chickens used was 75. The use of sweet potato waste fermentation in the ration had no significant effect (P>0.05) on initial body weight, final body weight , weight gain,and feed convertion ratio. Feeding of fermented sweet potato waste to a level of 3% (R2) gave optimal results.

A thermostable extracellular α-amylase from Aspergillus flavus S2-OY: Purification, characterisation and application in raw starch hydrolysis

An amylolytic fungus was isolated locally from the soil of a cassava waste dumpsite. It was identified as Aspergillus flavus S2-OY using 18S rRNA gene sequencing with gene bank accession number MZ267053.1. α-Amylase was produced from the fungus through solid substrate fermentation of potato (Solanum tuberosum L.) peel, a cheap and renewable substrate. The fungal enzyme was purified 13.41-fold by ammonium sulphate and ion exchange chromatography (CM Sephadex C-50), with final yield of 13.41%. Apparent molecular weight of 55.0 kDa was obtained for the purified enzyme, using SDS-PAGE. Optima pH (6.0) and temperature (70 °C) of α-amylase activity were determined for the enzyme which also showed thermal stability up to 70 °C, with 80% residual activity after 120 min. The enzyme exhibited a wide range of pH stability (4.0 to 7.0). Kinetic parameters Km and Vmax values obtained with soluble starch were 158 µg/ml/min and 1.51 mg/ml, respectively. The enzyme was slightly inhibited by Mg2+. Mn2+, Zn2+, Na+, K+, Hg2+ and the chelating agent, EDTA, at 5.0 mM concentration. However, it was activated by Sn2+. The enzyme hydrolysed gelatinised and ungelatinized raw yam, corn, rice and millet starches strongly but cassava starch moderately. These results revealed that cost-effective α-amylase production from Aspergillus flavus S2-OY could be realised with the use of potato peel as a cheap substrate, under solid substrate fermentation condition. Also, the fungal α-amylase is a raw starch-hydrolysing, acid to neutral and thermostable enzyme with potential for broad biotechnological applications.

Potentially lactic acid bacteria as an EPS producing starter from yellow sweet potato fermentation


 Potentially lactic acid bacteria as a starter for EPS production from yellow sweet potato fermentation were determined. The fermentation profile and partial characteristics of isolated lactic acid bacteria were used as considerations. The fermentation of yellow sweet potato was performed in the back-slopping and spontaneous procedure and was paid attention to the hours of 0, 24, 48, and 72. The results showed that the 72 hours of fermentation was found to have the highest EPS metabolites, the number of a LAB, the total lactic acid, and the lowest pH. The 72 hours of fermentation also seemed to cause a significant change in the sweet potato starch granules morphology. The potential starter, therefore, can be taken from the yellow sweet potato fermentation either spontaneously or by a back-slopping method, at 72 hours. From the sixty selected LAB, the 34 strains showed an ability to produce EPS. Among these, eight strains exhibited the potential high production of EPS. They were capable of growth on 28-45C and exhibited tolerance to 3-4% NaCl. The favorable carbon sources for the growth and production of EPS were isolated dependent.

Produção de álcool de batata-doce variando as condições de fermentação e hidrólise

Bioethanol is a renewable fuel as an alternative source of energy of worldwide importance. The present study aimed to evaluate alcohol production from sweet potato, under varying reaction conditions for fermentation and hydrolysis. A genotype was selected to obtain dried flour and processed by acid hydrolysis and enzymatic hydrolysis with α-amilase and amiloglucosidase. The experiment was carried out in a completely randomized block design with three central point replicates combined with response surface methodology. The variables were pH, temperature and fermentation time. The alcohol content was determined by distillation with subsequent spectrophotometric analysis. Raw materials were characterized according to moisture, reducing sugars and starch, and 4.13%, 4.04% and 71.80% were obtained, respectively. Acid hydrolysis showed higher alcohol percentages of distilled samples. The highest values for acid hydrolysis and enzymatic hydrolysis in fermentations were 26.42% and 25.04%, respectively, carried out at pH 5.0 and 36°C for 5 days. The fermentation time was the most important variable, with higher and significant values for both types of hydrolysis. Acid hydrolysis presented higher potential for alcoholic production than enzymatic hydrolysis in sweet potato fermentation.

Non-airtight Fermentation of Dairy Manure with Waste Potato Peels and Subsequent Phosphorus Recovery via Struvite Precipitation.

Two-phase anaerobic co-digestion of lignocellulosic crop residues with animal wastes can efficiently generate more biogas compared with the digestion of animal waste alone. Non-airtight fermentation of the mixed substrates is the primary step to hydrolyze complex organics and achieve simultaneous phosphorus release. Recycling phosphorus from tremendous animal wastes is remarkably meaningful regarding non-renewable resource recovery. In this study, the feasibility of a two-step process combining non-airtight fermentation of potato peels with dairy manure and the following struvite precipitation was explored. The hydrolysis and acidification process of the 6-day non-airtight mesophilic fermentation lowered pH to 6.4 under the highest mixed solid content of 4.8%; meanwhile, the ratio of reactive phosphorus to total phosphorus increased from 49.6 to 93.7% accordingly. Struvite formation was successfully induced by adjusting pH to 8.0 and 9.5. Under these two pHs, the precipitates were dominated by struvite as characterized by X-ray diffraction (XRD). Scanning electron microscopy and energy-dispersive spectrometry (SEM-EDS) results indicated that there should exist both struvite and calcium phosphate in the precipitates obtained under the two pHs. pH 8.0 precipitate should contain around 75% struvite, while the proportion rose to about 90% for pH 9.5 precipitate, based on the calculation of respective Mg/P and Ca/P molar ratios.

Produtividade de alface e qualidade de mudas de tomateiro com bioproduto de batata

O objetivo deste trabalho foi avaliar o efeito da aplicação de Acrescent Foliar®, proveniente da fermentação alcoolica de batata, na produtividade de alface e na qualidade de mudas de tomateiro. Foram conduzidos a campo dois experimentos com a cultura da alface, em delineamento blocos ao acaso com três repetições, e dois experimentos em ambiente protegido com mudas de tomateiro, em bandejas de poliestireno expandido de 128 células, em delineamento inteiramente casualizado com quatro repetições. Foram avaliados a fitomassa fresca e a fitomassa seca da parte aérea da alface, a altura da planta, o diâmetro do caule, o número de folhas, a fitomassa fresca de raiz, a fitomassa fresca de parte aérea, a fitomassa seca de parte aérea e a relação entre a fitomassa fresca de parte aérea e de raiz nas mudas de tomateiro. A adubação foliar com Acrescent Foliar® não influencia na produtividade da alface e confere às mudas de tomateiro características indesejáveis como redução da fitomassa fresca de raiz e aumento da relação entre a fitomassa fresca de parte aérea e de raiz.

Amylatic Activity of Agaricus and Moulds for the Production of Bioethanol

Fermentation of potato and carambola juice was investigated using Molds and Agaricus as a potential source of amylase. The amylatic activity of Moulds and Agaricus were studied and the effects of different parameters, such as starch concentrations, pH, incubation time, temperature were investigated. The maximum enzyme activity obtained for Moulds were 173 to 178U/g under the optimum conditions of an incubation period of 30min, 1.5 % starch solution, an incubation temperature of 60°C and a pH of 5.0. For Agaricus, the highest amylase production was 14 to 16U/g using 1.5 % starch solution, pH of 6.0 incubated at 75°C for 30 minutes. Reducing sugar was produced by fermentation of potato and carambola juice using mold and saccarification was conducted for production of bioethanol using yeasts. The ethanol produced from potato and carambola was approximately 11% (v/w) and 5% (v/v) respectively.

Simultaneous hydrogen and ethanol production from sweet potato via dark fermentation

The indigenous bacteria, cow dung and sewage sludge were used as seed microflora sources to ferment sweet potato into hydrogen and ethanol under batch cultivation at a temperature of 37°C. Hydrogen and ethanol production was evaluated based on their yields (HY and EY) and production rate (HPR and EPR) at various sweet potato concentrations (30–240g/L), sweet potato particle diameters (<1.19mm to >6.38mm) and initial cultivation pH conditions (4.0–9.0). The experimental results indicate an interesting finding that sweet potato fermentation without adding external seed (i.e., the fermenter contained only the indigenous bacteria which were identified to have seven species) could produce hydrogen and ethanol (EtOH). The indigenous bacterial community analysis showed that Klebsiella oxytoca, Clostridium fimetarium, Grimontella senegalensis, and Enterobacter asburiae (or Escherichia coli) were present at peak ethanol production and two more species Ruminococcus schinkii and Lactovum miscens were present at peak hydrogen production.The externally seeding strategy could enhance the hydrogen production from sweet potato with peak cumulative H2 production potential (HP) of 120mmolH2/L-reactor using sewage sludge. However, the cow dung seed showed more ethanol production than hydrogen with peak concentration of 12,146mgCOD/L. Increasing the sweet potato concentration could enhance the HPR and HP values. Maximum HY of 1.24molH2/molhexose was obtained at a substrate concentration of 150g/L with an initial cultivation pH of 6.7 and particle diameter <1.19mm using sewage sludge. The HPRmax, HY and HP values were affected slightly by the variations in sweet potato particle size. The peak total energy production yield of 1625J/g sweet potato was obtained with sweet potato concentration of 150g/L at pH 8.5 using sewage sludge.

Immobilized purple bacteria for light‐driven H2 production from starch and potato fermentation effluents

The goal of the study was to show that immobilized purple bacteria could photoproduce H(2) using dark fermentation effluent (FE) as substrate. Simple pretreatment of an inexpensive glass-fiber matrix accelerated the immobilization process. Photobioreactors (PhBR) containing immobilized Rhodobacter sphaeroides GL produced 0.128 L H(2) h(-1) L(-1) of PhBR volume (0.570 L h(-1) L(-1) of matrix) for up to 3 months when continuously fed artificial media with volatile fatty acids (VFAs) or FE from potato and starch fermentations. Hydrogen production was insensitive to NH(4)(+) up to 1 mM and saturated at 8 mM lactate or 1.5% potato FE (diluted in water and supplemented with critical micronutrients). The efficiency of VFA transformation to H(2) was 50-70% of theoretical. At nonlimiting substrate concentrations in artificial media or FE, acetate was utilized before butyrate. High volumetric rates of continuous H(2) photoproduction and stability of the process are advantages of using immobilized cultures. Use of H(2) photoproduction as a polishing step in the treatment of FEs from dark fermentations increased the total amount of H(2) produced from 0.9 to 4.7 mol mol(-1) glucose equivalent in the original potato homogenate.

Towards the integration of dark- and photo-fermentative waste treatment. 3. Potato as substrate for sequential dark fermentation and light-driven H 2 production

The goal of the study was to characterize H 2 production in an integrated process utilizing potato homogenate (PH) for dark, fermentative H 2 production followed by H 2 photoproduction using purple non-sulfur bacteria. Emphasis was placed on (a) examining potato fermentation effluent (FE) as substrate for H 2 photoproduction, (b) estimating the yield and efficiency of both processes, and (c) elucidating the physiological factors influencing the integrated system as a whole. In the dark stage maximal production of gas (11.5 L L −1 of the culture) and VFA (350 mM) were observed with a PH concentration of 400 g L −1 of medium, but higher yields (0.05 L g −1 PH; 1.9 mmol g −1 PH) were obtained at PH concentrations of 50–100 g L −1. H 2 photoproduction by purple bacteria was inhibited at high FE content. Upon suitable dilution, adequate illumination, and supplementation with Fe/Mg/phosphate nutrients, H 2 photoproduction reached 40 L L −1 of non-diluted FE, with a total H 2 yield of 5.6 mol mol −1 glucose equivalent for the two-stage integrated process.

二相循環式水素・メタン発酵プロセスにおける微生物群集の構造解析

The structure of a microbial community during a two-phase circulating process for the hydrogen and methane fermentation of potato was investigated using a molecular biological approach. The process was performed using a mixing tank, a thermophilic acidogenic reactor (55°C) and a mesophilic methanogenic reactor (36°C) connected in series with the recirculation of methanogenic mixed liquor to the mixing tank. A continuous experiment was conducted by changing the process hydraulic retention time (HRT) stepwise from 56 days to 30 days, then 20 days and 15 days. A stable and high-rate hydrogen and methane fermentation was possible at a process HRT of 20 days with a hydrogen production rate of 3.6 l·l-1·d-1 and a methane production rate of 3.4 l·l-1·d-1. Denaturing gradient gel electrophoresis (DGGE) with 16S rRNA gene-targeted polymerase chain reaction (PCR) analysis was employed to identify the structure of a microbial community at various conditions for each reactor. Thermoanaerobacterium thermosaccharolyticum and Clostridium sporosphaeroides were considered to be the major hydrogen-producing bacteria in the thermophilic acidogenic reactor, whereas Methanosarcina siciliae and Methanoculleus bourgensis were considered, respectively, to be the acetate-utilizing and hydrogen-utilizing methanogenic archaea in the mesophilic methanogenic reactor.

Direct fermentation of potato starch to ethanol by cocultures of Aspergillus niger and Saccharomyces cerevisiae.

Direct fermentation of unhydrolyzed potato starch to ethanol by monocultures of an amylolytic fungus, Aspergillus niger, and cocultures of A. niger and Saccharomyces cerevisiae was investigated. Amylolytic activity, rate and amount of starch utilization, and ethanol yields increased several-fold in coculture versus the monoculture due to the synergistic metabolic interactions between the species. Optimal ethanol yields were obtained in the pH range 5 to 6 and amylolytic activity was obtained in the pH range 5 to 8. Ethanol yields were maximal when fermentations were conducted anaerobically. Increasing S. cerevisiae inoculum in the coculture from 4 to 12% gave a dramatic increase in the rate of ethanol production, and ethanol yields of greater than 96% of the theoretical maximum were obtained within 2 days of fermentation. These results indicate that simultaneous fermentation of starch to ethanol can be conducted efficiently by using cocultures of the amylolytic fungus A. niger and a nonamylolytic sugar fermenter, S. cerevisiae.