Fermentation Effect on the Properties of Sweet Potato Starch and its Noodle's Quality byLactobacillus plantarum

The effect of lactic acid bacteria fermentation on physicochemical properties of starch from fermented proso millet flour

A waxy and a non-waxy proso millet flour were each fermented by Lactobacillus amylovorus, Lactobacillus fermentum, and Lactobacillus plantarum. The samples were fermented for one to five days, and starch was isolated from the fermented flours. The pH of fermented proso millet flour ranged from 3.27 to 3.6. The starch morphology of fermented samples differed from that of raw starches, with surface indentations and small pores leading to granule channels observed on the granule. The gelatinization temperatures were significantly decreased, whereas the enthalpies were not affected by fermentation. Peak and final viscosities were decreased after fermentation. The hardness of Lb. fermentum and Lb. plantarum fermented waxy starch gels was decreased, but the non-waxy samples fermented by Lb. amylovorus had significantly increased hardness. The adhesiveness of the starch gels from fermented samples was significantly increased. Lactic acid fermentation had significant effects on the morphology and physicochemical properties of proso millet starch.

Effects of Co-Fermentation of Lactiplantibacillus plantarum and Saccharomyces cerevisiae on Digestive and Quality Properties of Steamed Bread

The leavening of wheat-based steamed bread is carried out either with a pure yeast culture or with traditional starter cultures containing both lactic acid bacteria and yeast/mold. The use of variable starter cultures significantly affects steamed bread's quality attributes, including nutritional profile. In this paper, differences in physicochemical properties, the type of digested starch, the production of free amino acids, and the specific volume of steamed bread under three fermentation methods (blank, yeast, and LP-GM4-yeast) were compared. The digestion characteristics (protein and starch hydrolysis) of steamed bread produced by using either yeast alone or a combination of Lactiplantibacillus plantrum and yeast (LP-GM4-yeast) were analyzed by an in vitro simulated digestion technique. It was found that the specific volume of steamed bread fermented by LP-GM4-yeast co-culture was increased by about 32%, the proportion of resistant starch was significantly increased (more than double), and soluble protein with molecular weight of 30-40 kDa was significantly increased. The results of this study showed that steamed bread produced by LP-GM4-yeast co-culture is more beneficial to human health than that by single culture.

Starch-based noodles: Current technologies, properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.

Improving Phenolic Bioactive-Linked Functional Qualities of Sweet Potatoes Using Beneficial Lactic Acid Bacteria-Based Biotransformation Strategy

Beneficial lactic acid bacteria (LAB) based fermentation is an effective biotransformation strategy to preserve and improve the human health-supporting functional qualities of plant-based food substrates. In this study, a food grade strain of Lactiplantibacillus plantarum was recruited to improve the retention, stability, and bioavailability of phenolic bioactives to enhance the antioxidant, anti-hyperglycemic, and anti-hypertensive functional qualities of three flesh-colored sweet potato varieties, Murasaki (off-white-fleshed), Evangeline (orange-fleshed), and NIC-413 (purple-fleshed). Liquid (cold water) extracts of the sweet potatoes, which are relevant for food grade applications, were fermented for 72 h at 37 °C. Total soluble phenolic content, phenolic profile, antioxidant, anti-hyperglycemic, and anti-hypertensive benefits relevant functional properties of fermented and unfermented sweet potato extracts were evaluated at 0, 24, 48, and 72 h time points using in vitro assay models. Overall, high total soluble phenolic content and total antioxidant activity were observed at 24 h, retaining this high level even after 72 h of fermentation. Additionally, moderate to high α-amylase, α-glucosidase, and angiotensin-I-converting enzyme inhibitory activities were observed in the fermented sweet potato extracts. The results suggested that LAB-based fermentation is an effective post-harvest processing strategy for a higher retention of phenolic bioactives and concurrently improves the human health protective bioactive functional qualities of sweet potatoes.

Analysis of Sour Porridge Microbiota and Improvement of Cooking Quality via Pure Culture Fermentation Using Lacticaseibacillus paracasei Strain SZ02

The microbial composition of sour porridge at different fermentation times was analyzed through high-throughput sequencing, and a pure culture fermentation process was established to optimize production process and improve the edible quality of the porridge. In natural fermentation, Firmicutes and Proteobacteria were abundant throughout the process. Specifically, Aeromonas, Acinetobacter, and Klebsiella were dominant on fermentation days 1–5 (groups NF-1, NF-3, and NF-5), while Lactobacillus and Acetobacter gradually became the dominant bacteria on fermentation day 7 (group NF-7). Further, we isolated one strain of acid-producing bacteria from sour porridge, identified as Lacticaseibacillus paracasei by 16SrRNA sequencing and annotated as strain SZ02. Pure culture fermentation using this strain significantly increased the relative starch and amylose contents of the porridge, while decreasing the lipid, protein, and ash contents (P < 0.05). These findings suggest that sour porridge produced using strain SZ02 has superior edible qualities and this strategy may be exploited for its industrial production.

Trend of Modification by Autoclave at Low Pressure and by Natural Fermentation in Sweet Potato and Cassava Starches

Sweet potatoes (Ipomoea batatas L.) and cassava (Manihot esculenta C.) are part of the largest food crops in many countries. They have good nutritional value because, in addition to containing vitamins, minerals, carotenoids, and anthocyanins in varied contents, due to the existence of various colors of their pulps, they have starch as their major constituent. As such, they are considered valuable raw materials for the food factory. The starch granules have distinct morphologies and properties, related to the type of cultivar, planting conditions, storage, and processing, which in turn can affect the quality of the final products to which they have been added. The use of native starches in the food industry has limitations, which can be improved by modifications. Physical methods, as they are associated with green technology, and do not pollute the environment, have demonstrated great potential for this purpose. Both modifications—by autoclave at low pressure and natural fermentation—have shown potential in modifying these starches.

Characterization of Striga-Resistant Yellow-Orange Maize Hybrids for Bioactive, Carbohydrate, and Pasting Properties

Understanding the bioactive constituents and physicochemical components in cereals can provide insights into their potential health benefits and food applications. This study evaluated some bioactive constituents, carbohydrate profiles and pasting properties of 16 Striga-resistant hybrids, with yellow-orange kernel color and semi-flint to flint kernel texture, grown in two replications at two field locations in Nigeria. Carotenoids were quantified using HPLC, while other analyses were carried out using standard laboratory methods. The ranges of major carotenoids (μg/g) across the two locations varied from 2.6 to 9.6 for lutein, from 2.1 to 9.7 for zeaxanthin, from 0.8 to 2.9 for β-cryptoxanthin, from 1.4 to 4.1 for β-carotene; with total xanthophylls and provitamin A carotenoids (pVAC) ranging from 5.4 to 17.1 and 1.4 to 4.1 μg/g, respectively. Tannins content ranged from 2.1 to 7.3 mg/g, while phytate ranged from 0.4 to 7.1%. Starch, free sugar, amylose and amylopectin ranged from 40.1 to 88.9%, 1.09 to 6.5%, 15.0 to 34.1%, and 65.9 to 85.0%, respectively. Peak and final viscosities ranged from 57.8 to 114.9 and 120.3 to 261.6 Rapid Visco Units (RVU), respectively. Total xanthophylls, β-carotene, tannins, phytate, sugar, amylose and amylopectin levels, as well as peak and final viscosities, varied significantly (p &lt; 0.05) across the hybrids. Amylose was significantly correlated (p &lt; 0.05) with total xanthophylls, β-carotene, pVAC, phytate and pasting temperature (r = 0.3, 0.3, 0.4, 0.3, 0.3, respectively), but starch significantly correlated with tannins (r = 0.3). Hence, the Striga-resistant yellow-orange maize hybrids have a good combination of bioactive constituents, carbohydrate profile and pasting properties, which are partly influenced by hybrid.

Physicochemical properties of potato starch fermented by amylolytic Lactobacillus plantarum

This study investigated the effect of fermentation by Lactobacillus plantarum CGMCC 14177 strain on physicochemical properties and morphological characteristics of potato starch. The maximum total amylase and α-amylase production of L. plantarum CGMCC 14177 were 286.8 and 208.1 U/g, respectively. Fermented granules clearly exhibited pocked and dimpled surfaces. The granule properties changed to have a 1.9% increase in relative crystallinity. Overall the starch changed to have slight increases in onset and peak temperature, but resulted decreases of conclusion temperature and enthalpy. Fermentation decreased peak viscosity and breakdown value, while increased trough viscosity, final viscosity, and setback. Further analysis showed that fermentation increased the gel hardness and chewiness of the potato starch, but made little differences in the springiness, cohesiveness and resilience. Collectively, these results provide insight on how Lactobacillus strains can be used to modify the physicochemical properties of potato starch in ways that extend its use in industrial applications.

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.