Effect Of Lactic Acid Fermentation Research Articles

EFFECT OF LACTIC ACID FERMENTATION OF CASSAVA ON FUNCTIONAL AND SENSORY CHARACTERISTICS OFFUFUFLOUR

ABSTRACT The effects of lactic acid fermentation of cassava on the functional and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65C in a cabinet dryer for 48 h, and were analyzed for functional and sensory characteristics. Fermentation reduced the water-binding capacity of the fufu flour from 176.6% to between 118 and 125%. The pasting characteristics of the traditional and starter culture-fermented fufu flour samples were not significantly different from that of the unfermented cassava flour. When subjected to sensory evaluation, the traditional and starter culture-fermented cassava fufu flour were not significantly different in terms of color, odor and texture, but the cassava fufu flour produced, using starter culture SL19, had the highest overall acceptability (P < 0.05). PRACTICAL APPLICATIONS Traditionally, processing of cassava to fufu is usually carried out by using the old stock from a previous fermentation to initiate the fermentation of a new batch. This old method usually results in fufu that has a strong odor that may not be acceptable to some consumers. The use of starter culture like Lactobacillus plantarum will reduce the strong odor of fufu; this will increase its acceptability by consumers and ensure the overall quality. Also, the functional properties of fufu are not affected. The development of lactobacilli strains could help in optimizing the traditional processes, therefore increasing the economic returns.

Effects of lactic acid fermentation on FT-IR and pasting properties of rice flour

The Lactobacillus fermentum R1 and Lactobacillus delbrueckii subsp. delbrueckii R2 were two dominant lactic acid bacteria strains in mixed starters, intensively used to manufacture fermented rice noodle in Hunan province of China. In this paper, the FT-IR and RVA pasting properties of fermented rice flour were investigated with each of dominant strains as single starter. The ester carbonyl group band at 1742 cm −1 and IR absorbance band at 1047 cm −1 disappeared in the FT-IR spectra of fermented rice flour. The FT-IR absorbance band at 1046.86 cm −1 was detected only in non-fermented rice flour. Both breakdown and setback RVA parameters of fermented rice flours reduced. The results suggested that the effects of lactic acid fermentation of two dominant strains on the FT-IR and RVA pasting properties of rice flour were same and the crystal structures in starch granules were moderately damaged during fermentation process.

English

The effects of lactic acid fermentation of cassava on the chemical and sensory characteristic of fufu flour were investigated. Two strains of&nbsp;Lactobacillus plantarumwere used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65oC in a cabinet dryer for 48 h and analyzed for chemical and sensory characteristics. Fermentation caused a high reduction in the protein content of cassava, which ranges between 1.26 &plusmn; 0.02% for cassava with starter culture SL 14, and 1.14 &plusmn; 0.04% for cassava with starter culture SL 19. However, the unfermented cassava fufu flour has the highest protein content; this shows the influence of fermentation in reducing the proximate composition of cassava. The values of the sugar, starch and amylose contents show similar trends. The sugar contents ranges between 5.21 &plusmn; 0.04 to 4.41 &plusmn; 0.0%, with the unfermented sample having the highest value. When subjected to sensory evaluation, the traditional and starter-culture fermented cassava fufu flour were not significantly different in terms of color, odor, and texture, but the cassava fufu flour produced using starter culture SL19 had the highest overall acceptability (P&lt;0.05). &nbsp; Key words:&nbsp;Cassava, fermentation, Lactobacillus plantarum, chemical composition, sensory characteristic.

Effect of lactic acid fermentation of onions (Allium cepa) on the composition of flavonol glucosides

SummaryFermentation of red onions inoculated with Lactobacillus plantarum S1 (starter treatment) resulted in acid production to pH 4.5, after 48 h of incubation at 19 °C, which has proven to be adequate for proper preservation. In the presence of erythromycin (starter + antibiotic), acidification to pH 5.2 resulted, which was similar to that of the uninoculated control. The bacterial population was about 108 CFU mL−1 of brine after 3 days for the three treatments, suggesting that in the starter + antibiotic treatment, the antibiotic effectively suppressed the activity of the starter but not the native flora. Before lactic fermentation, the red onions contained 297.4 mg of total quercetin (Q) per kg wet weight, which consisted of 58.3%, 41.6% and 0.1% in quercetin diglucoside (Qdg), quercetin monoglucoside (Qmg) and free Q, respectively. For the starter treatment, Qdg decreased to 41.8% and 18.3% at 48 and 72 h, respectively, and a substantial amount of free Q had accumulated. The fermentation substantially increased the proportion of Qmg, which may have a positive effect as fractions containing higher ratios of Qmg to Qdg have been reported to have higher antioxidant activity.

Effects of lactic acid fermentation and gamma irradiation of barley on antinutrient contents and nutrient digestibility in mink (Mustela vison) with and without dietary enzyme supplement

The experiment was conducted to study the effects of fermentation of barley, using two different strains of lactic acid bacteria, a Lactobacillus plantarum/pentosus strain isolated from spontaneously fermented rye sourdough (AD2) and a starch-degrading Lactobacillus plantarum (AM4), on contents of mixed-linked (1 → 3) (1 → 4)-β-glucans, α-amylase inhibitor activity, inositol phosphates, and apparent digestibility of macronutrients in mink. Effects of fermentation were compared with effects of gamma irradiation (γ-irradiation: 60Co γ-rays at 25 kGy). The diets were fed to mink with and without a supplementary enzyme preparation. Both lactic acid fermentation and γ-irradiation followed by soaking and incubation, reduced concentrations of soluble β-glucans, phytate and α-amylase inhibitor activity. Dietary enzyme supplementation increased significantly digestibility of crude protein, fat, starch and crude carbohydrate (CHO). Fermentation of the barley increased digestibility of starch and CHO. Fermentation with lactic acid bacteria AD2 resulted in higher starch and CHO digestibility than strain AM4, and had greater effect than γ-irradiation, soaking and incubation. The highest digestibility of starch and CHO was obtained after AD2 fermentation followed by enzyme supplementation. It is concluded that both lactic acid fermentation of barley and enzyme supplementation have positive nutritional implications in the mink by limiting the effects of antinutrients and improving digestibility and energy utilization.

Effect of lactic acid bacteria starter culture fermentation of cassava on chemical and sensory characteristics of fufu flour

The effects of lactic acid fermentation of cassava on the chemical and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65oC in a cabinet dryer for 48 h and analyzed for chemical and sensory characteristics. Fermentation caused a high reduction in the protein content of cassava, which ranges between 1.26 ± 0.02% for cassava with starter culture SL 14, and 1.14 ± 0.04% for cassava with starter culture SL 19. However, the unfermented cassava fufu flour has the highest protein content; this shows the influence of fermentation in reducing the proximate composition of cassava. The values of the sugar, starch and amylose contents show similar trends. The sugar contents ranges between 5.21 ± 0.04 to 4.41 ± 0.0%, with the unfermented sample having the highest value. When subjected to sensory evaluation, the traditional and starterculture fermented cassava fufu flour were not significantly different in terms of color, odor, and texture, but the cassava fufu flour produced using starter culture SL19 had the highest overall acceptability (P<0.05).

Effect of Lactic Acid Fermentation on Enrichment of Antioxidant Properties and Bioactive Isoflavones in Soybean

ABSTRACT: The antioxidant properties of 80% ethanolic extracts from soybean obtained with lactic acid fermentation using ABTS•+ [2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt] free radical decolorization assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay were measured, and the relationship between the observed antioxidant properties and the compositional changes in the isoflavone isomers was evaluated. Fermentation of soybean with 4 bacterial strains producing β-glucosidase for 48 h at 37°C—Lactobacillus plantarum KFRI 00144, Lactobacillus delbrueckii subsp. latisKFRI01181, Bifidobacteriathermophilum KFRI00748, and Bifidobacteria breve K-101—resulted in a significant increas (P < 0.05) in the antioxidant capacity expressed as Trolox equivalent antioxidant capacity (TEAC) (mM) and % scavenging activity. The significant bioconversion (P < 0.001) of the isoflavone glucosides (daidzin + genistin) into their responding bioactive aglycones (daidzein + genistein) during soy fermentation was observed. There was a good linear correlation between the concentration of isoflavone aglycones and the scavenging activity of ABTS (R = 0.9045) assay, and DPPH (R = 0.8299) assay in each extract. Among each extract, B. thermophilum KFRI 00748 showed a particularly high antioxidant activity (19.8 mM TEAC) and increased by 4.1 times compared with that of the control (4.8 mM TEAC), which fermented without strains. These results indicated that fermented soybean could be regarded as a potent antioxidant and radical scavenging dietary source due to their remarkable content of bioactive isoflavones.

Effects of lactic acid fermentation on wheat and barley carbohydrate composition and production performance in the chicken

Effects of dietary inclusion of dried lactic acid fermented wheat or barley whole meal flours (WMF) on chicken performance were studied. WMFs were fermented for 16 h at 30 °C by a Lactobacillus strain isolated from a Norwegian rye sourdough. Four diets containing 600 g wheat WMF kg −1 (0, 200, 400 and 600 g fermented kg −1) and three diets containing 600 g barley WMF kg −1 (0, 400 and 600 g fermented kg −1) were used. Each treatment comprised 125 one-day-old sexed chickens (Ross) were fed on experimental diets until slaughtering at 35 days. Average weight, feed intake and feed:gain ratio in the 0–14, 14–35 and 0–35-day periods were recorded. At day 35, six chickens of each sex from each diet were slaughtered for determination of dressing percentage and abdominal fat. Fermentation significantly reduced levels of total and soluble dietary fibre in cereal WMF. In barley WMF, total β-glucans decreased from 36.9 to 29.3 g kg −1 dry matter (DM) and soluble β-glucans from 17.8 to 12.6 g kg −1 DM after fermentation. The effects of fermentation on dietary fibre and β-glucans were reflected in the analysis of the experimental diets. Total starch was not significantly affected by fermentation. Cereal source and level of fermented WMF in the diets significantly affected chicken body weights. At 14 days, average weights were increased from 277 to 333 g for wheat diets, and from 252 to 322 g for barley diets, when untreated WMF was entirely substituted by fermented WMF. Linear regressions showed significant increase in average weight at 14 days with increasing levels of fermented wheat ( R 2=0.448 ∗∗∗) and fermented barley ( R 2=0.604 ∗∗∗). The effects of fermentation on weights at 14 days were similar for wheat and barley, as there was no significant difference between the regression slopes. Feed intake during the 0–14-day period was not significantly affected by the content of fermented cereal in the diet. Increasing level of fermented cereal significantly improved feed:gain ratio during the 0–14-day period for both wheat ( R 2=0.329 ∗∗∗) and barley ( R 2=0.389 ∗∗∗). Level of fermented wheat had no significant effect on weight gain or feed intake in the 14–35-day period, while fermented barley significantly increased weight gain and feed intake in this period. At 35 days, average weights of chickens fed diets with solely untreated or fermented barley were 1344 and 1576 g, respectively. Feed:gain ratio in the 0–35-day period decreased significantly with increasing levels of fermented barley, but not with fermented wheat. Dressing percentage was not significantly affected by treatment. Abdominal fat increased significantly with increasing level of fermented cereal. It was concluded that fermentation of barley and wheat with a β-glucan-degrading lactic acid bacteria can improve growth and early feed:gain ratio in broiler chickens.

Lactic acid fermentation of wheat and barley whole meal flours improves digestibility of nutrients and energy in Atlantic salmon ( Salmo salar L.) diets

The effects of lactic acid fermentation of wheat and barley whole meal flours (WMF) on digestibility parameters in Atlantic salmon were studied. The WMFs were inoculated with a specific Lactobacillus strain and fermented for 16 h at 30 °C prior to mixing with other feed ingredients and processing by extrusion. Fermentation of the WMFs significantly decreased total starch ( P<0.01) and total mixed-linked (1–3)(1–4)-β-glucan ( P<0.001) contents in both cereals. Soluble β-glucans decreased ( P<0.001) from 25.2 to 12.0 g kg −1 dry matter in barley WMF during fermentation. In Experiment 1, where diets with 24% untreated wheat or barley WMF and 12%, 24%, or 36% fermented WMFs were fed to Atlantic salmon (0.5 kg) for 25 days, there were indications of improved starch and fat digestibility by fermentation. Experiment 2 comprised diets containing 24% untreated or fermented wheat or barley WMFs fed to each of triplicate groups of Atlantic salmon (0.5 kg) during a 17-day experimental period. This experiment showed that protein ( P<0.001), fat ( P<0.05) and energy ( P<0.001) were more efficiently digested in diets with wheat than in diets with barley. Apparent digestibility of starch was greatly improved by fermentation ( P<0.001), more in barley diets (from 47.5% to 67.0%) than in wheat diets (from 51.7% to 65.4%). Improvements in digestibility of fat ( P<0.05) and energy ( P<0.001) were obtained by fermenting the cereals. The absorption of Na was higher for salmon fed wheat than barley diets ( P<0.05). Fermentation resulted in improved Na absorption ( P<0.01); from 68.8% to 73.2% for wheat diets and from 60.3% to 71.7% for barley diets. Fermentation caused a significant ( P<0.05) improvement in Zn absorption from 32.7% to 40.5% for wheat diets and from 33.2% to 43.5% for barley diets. This may be related to the significant reduction in phytic acid levels seen in both fermented cereals ( P<0.001). In conclusion, the potential of wheat and especially barley as ingredients in salmon diets is greatly improved by fermentation.

Effect of lactic acid fermentation of wheat and barley whole meal flour on carbohydrate composition and digestibility in mink ( Mustela vison)

Wheat and barley whole meal flours (WMFs) were subjected to treatment by fermentation, autoclaving, and fermentation followed by autoclaving. The WMFs were analysed for chemical composition, formulated into wet diets (282 g kg −1) and fed to adult mink ( Mustela vison) for determination of total tract digestibility of total starch, total carbohydrate, crude protein and fat. Fermentation of WMF/water mixtures inoculated with a Lactobacillus sp. (strain AD 2) was performed at 30°C for 16 h. Autoclaving was carried out for 60 min at 120°C. Fermentation increased colony-forming units (CFUs) to about 10 8 g −1 and lowered pH to 3.7–3.8 in both WMFs. All carbohydrate parameters were affected by type of cereal, and were, except for total starch, affected by treatment. Levels of total dietary fibre and β-glucans decreased by fermentation in both WMFs. The decrease in total β-glucans from 33.5 to 18.4 g kg −1 in barley WMF, was mainly restricted to the soluble fraction. Glucose levels in barley WMF increased simultaneously from 0.6 to 12.3 g kg −1. The main effects of autoclaving were increased levels of total dietary fibre, maltose, and increased hydration capacity. With fermentation prior to autoclaving, increases in levels of the fibre fractions and maltose were prevented while hydration capacity prevailed as an effect of autoclaving. Compared with fermentation alone, the combined treatment increased damaged starch levels and hydration capacity. Digestibilities of total carbohydrate, crude protein and fat were significantly higher for wheat than for barley. Fermentation had no effect on digestibility of total starch or total carbohydrate of wheat, but increased digestibility of total starch of barley significantly from 0.742 to 0.880, and of total carbohydrate from 0.457 to 0.616. Autoclaving had no significant effect on digestibility of total starch and total carbohydrate of wheat. Digestibility of total starch and total carbohydrate in barley increased significantly after autoclaving. Total starch and total carbohydrate digestibility of both wheat and barley were significantly enhanced by combined fermentation and autoclaving compared with fermentation alone. Compared with autoclaving alone, combined fermentation and autoclaving promoted no significant improvement of total starch and total carbohydrate digestibility in wheat, whereas total carbohydrate digestibility in barley increased from 0.605 to 0.672. Fat digestibility was slightly improved by both fermentation and autoclaving. Autoclaving of cereals reduced significantly the faecal dry matter contents of mink. This effect could be counteracted by preceding fermentation. In conclusion, lactic acid fermentation of wheat and especially barley provided chemical changes of benefit for carbohydrate digestion in the mink.

Assessment of fermentation as a household technology for improving food safety: a joint FAO/WHO workshop

Food safety and nutritional aspects of lactic acid fermentation processes for the purpose of complementary food preparation at household scale in tropical countries were assessed during an FAO/WHO workshop held in Pretoria, South Africa in December 1995. Lactic acid fermentation was evaluated in particular, taking into consideration that microbial fermentation is only a part of the food preparation processes involving other operations such as soaking, cooking and the use of germinated cereals. The latter are of special interest as they enable the preparation of semiliquid porridges of high-nutrient density. The present state of knowledge concerning the antimicrobial effects imparted by the acidity in lactic-fermented foods was reviewed, as well as the nutritional benefits of fermentation and use of germinated cereals. Areas requiring further research were identified and prioritized. It was concluded that high priority should be given to research on: the effect of lactic acid fermentation on viruses, parasites, some bacteria and mycotoxins; risk assessment using the HACCP approach, health education of food handlers and consumer perception of fermented foods; characterization and optimization of fermentation processes and development of appropriate starters; and some physiological and nutritional effects of consumption of fermented foods.

Lactic acid fermented foods and their benefits in Asia

This paper reviews many types of the world's lactic acid fermented foods and discusses the beneficial effects of lactic acid fermentation of food by focusing on two examples taken from Korean cuisine, kimchi and sikhae. Sikhae is the generic name for a class of Korean lactic acid fermented fish products that contain 6–8% salt and generally are at pH 4–5. Koreans are able to preserve fish for 1–2 months at ambient temperatures by this method. Due to the low salt content, sikhae contributes much-needed protein to the Korean rice-based diet. Kimchi is the generic name for a class of Korean lactic acid fermented vegetables that contain 3–4% salt and generally are at pH 4.0–4.5. Kimchi is an important source of vitamins and minerals especially during the wintertime. It is a popular side-dish and provides a source of intestinal lactic acid bacteria. The physiological effects of kimchi have been studied widely in Korea and recent results are summarized in this paper.

Effect of Lactic Acid Fermentation on Bacterial Pathogens and Indicator Organisms in Broiler Processing Waste

Broiler processing offal (heads, viscera, and feet) was collected on 3 separate days from a commercial processing plant. Each sample was separately ground, supplemented with sucrose (6% initial concentration), inoculated with actively growing lactic acid bacteria (106 cfu/g of offal) from a commercial silage culture, and fermented at 37 C. Replicate samples were taken for standard microbiological analysis after 0, 48, and 120 h of fermentation. In fresh offal, heterotrophic plate count, total and fecal coliforms, fecal streptococci, and Aeromonas hydrophila concentrations were 7.4, 5.9, 5.9, 5.4, and 3.9 log10 cfu/g wet weight, respectively. After 48 h of fermentation, the bacterial concentrations were 7.6, 2.2, <1.3, 5.5, and <2.3 log10 cfu/g wet weight, respectively. After 120h of fermentation, the bacterial concentrations were 6.9, <1.1, <1.1, <1.1, and <1.1 log10 cfu/g wet weight, respectively. Salmonella concentrations in fresh, 48-h fermented, and 120-h fermented offal samples were 3.7, <1.5, and <1.5 log10 most-probable-number/100 g wet weight, respectively. Lactic acid fermentation appears to be effective in reducing the number of bacterial pathogens and indicator organisms in poultry processing offal.