Sour Starch Research Articles

Extend the emphasis to encompass sweet potatoes health advantages, industrial applications, and nutritional qualities

ABSTRACT Sweet potatoes (Ipomoea batatas L.) are a key food crop in tropical and subtropical regions, notably Asia, Africa, and the Pacific. Asia and Africa account for 95% of global production. Sweet potatoes’ tendrils, leaves, tubers, and stems are rich in vitamins, minerals, fats, carbs, and proteins. Research indicates that bioactive compounds such as β-carotene, anthocyanins, polyphenols, and phytochemicals can reduce cardiovascular disease risk and have antidiabetic, anti-inflammatory, antimicrobial, anticancer, anti-obesity, antioxidant, and hepatoprotective effects. Beyond food security, sweet potatoes can generate revenue through the creation of functional foods and beverages, such as sour starch, sweet potato curd, lacto-pickles, lacto-juice, acidophilus milk, soy sauce, and alcoholic drinks via solid-state or submerged fermentation. This article aims to comprehensively review the bio-processing of sweet potatoes into industrial products and their phytochemical and therapeutic profiles.

Evaluating the Impact of Inulin Addition before Solar Drying on the Characteristics of Sour Cassava Starch as a Food Ingredient

AbstractSour cassava starch is obtained by spontaneous fermentation of the starch cake immediately after being extracted, followed by sun‐drying, where oxidation reactions take place that are essential for the enhanced baking expansion of this starch. The aim of this work is to evaluate the influence of adding a different polysaccharide to the starch cake before sun‐drying in the characteristics of the obtained product. Inulin is chosen for being a soluble prebiotic fiber that may improve the nutritional quality of the starch. Inulin modifies the oxidation of the fermented starch during sun‐drying, and forms a film around the granules that hinder their swelling and water retention capacity. The crystallinity of the inulin is increased by hydration and sun‐drying. Adding inulin to the fermented starch before sun‐drying reduces its expansion capacity, but in a lower rate than when inulin is added after sun‐drying. The fermented starch sun‐dried with inulin produces a baked snack with similar texture to that of the sour starch alone, and softer than that from the native starch.

Fungal communities in Brazilian cassava tubers and food products

Cassava (Manihot esculenta Crantz) is one of the most widely cultivated foods in the world and is of great socio-economic importance, especially in developing countries. It is predominantly consumed in boiled form, but also is used to produce a number of products, including cassava starch, sour starch, cassava flour and tapioca flour (hydrated cassava starch). Fungal spoilage can occur throughout the production chain, impairing both productivity and quality, as well as posing a potential risk of contamination by mycotoxins. We used multidisciplinary approaches based on phenotypic and molecular data (ITS/BenA/TEF-1a/RPB2 loci) to investigate the mycobiota of 101 samples (including roots, soil and products) collected in the state of São Paulo, Brazil. A total of 20 fungal groups/genera were morphologically characterized, and 37 different species were molecularly identified. The predominant groups in cassava tubers were Fusarium spp., Penicillium spp. and Trichoderma spp. In cassava products, the most frequent groups were Penicillium spp. and Paecilomyces spp. Potentially toxigenic species were also found, including Paecilomyces saturatus, Penicillium citrinum, P. paneum, P. brevicompactum, P. chrysogenum, Fusarium foetens and Fusarium mundagurra. In soil-cultivated cassava samples, the groups found most frequently were Penicillium spp., Cladosporium spp. and Fusarium spp. Some of the species found in cassava tubers and/or product samples were also present in the soil, including F. mundagurra, Neocosmospora solani, P. citrinum and P. brevicompactum. In general, there was a higher occurrence of Penicillium spp., Fusarium spp. and Trichoderma spp., and the predominant species were F. fabacearum and P. citrinum. The mycobiota of Brazilian cassava proved to be extremely diverse, and the occurrence of several species in cassava tubers and/or products are reported herein for the first time. Potentially toxigenic species were found in cassava tubers, cassava products and soil, showing how important it is to constantly monitor these substrates.

Can cassava improve the quality of gluten free breads?

The effect of incorporating different forms of cassava (flour, native and sour starch) on the quality of gluten-free breads was evaluated. Ten or 20% of a maize starch/rice flour mixture was replaced by these cassava products. Pasting and hydration properties of the mixtures were analysed. The rheology of doughs obtained was also studied. The breads produced were evaluated for specific volume, weight loss, texture, and sensory characteristics. The rheology of the doughs did not change with the addition of cassava starch, but cassava flour increased the G′ and G″ values. These changes are more related to the cold hydration properties than to the pasting properties of the mixes. Ten percent of cassava products incorporation improved the quality of the bread by increasing their specific volume. However, this increase was smaller when 20% of cassava products were added. The incorporation of 20% of cassava flour in breads reduced their specific volume significantly. Breads with cassava starch were softer after 7 days of storage than control bread. Furthermore, their crumbs were more cohesive and less dry in the mouth, especially for sour starch. Cassava starches and, to a lesser extent, cassava flours can help to improve the quality of gluten-free breads.

Aspergillus section Flavi and aflatoxins in Brazilian cassava (Manihot esculenta Crantz) and products.

Aflatoxins are carcinogenic compounds produced by some species of Aspergillus, especially those belonging to Aspergillus section Flavi. Their occurrence in food may start in the field, in the post-harvest, or during storage due to inadequate handling and storage. Because cassava is a staple food for a high percentage of the Brazilian population, we evaluated the presence of aflatoxin-producing species in cassava tubers, cassava products (cassava flour, cassava starch, sour starch, and tapioca flour), and in soil samples collected from cassava fields. In addition, the levels of aflatoxin contamination in cassava products were quantified. A total of 101 samples were analyzed, and 45 strains of Aspergillus section Flavi were isolated. Among the identified species, Aspergillus flavus, Aspergillus arachidicola, Aspergillus novoparasiticus, and Aspergillus parasiticus were found. The majority of strains (73.3%) tested for their aflatoxin-producing ability in synthetic media was positive. Despite that, cassava and cassava products were essentially free of aflatoxins, and only one sample of cassava flour contained traces of AFB1 (0.35μg/kg).

Fermentation and drying effects on bread-making potential of sour cassava and ahipa starches

Cassava sour starch is a gluten-free product obtained by natural fermentation and sun-drying that outstrips the native starch baking expansion properties. Although maize starch has been subjected to a similar process, this desirable feature could not be achieved. Ahipa, an unexploited tuberous root, renders starch with relatively low gelatinization temperature and amylose content, like that of cassava. The aim of this work was to study the characteristics and technological properties of ahipa starch subjected to different fermentation processes and drying methods (oven- or sun-drying) and compare the bakery quality of its derived products to those from fermented cassava starches.Ahipa starch followed similar fermentation paths to those followed by cassava's, and sun-drying significantly reduced the content of the resultant lactic and butyric acids. Rheological behavior of starch pastes as well as moisture content and hardness of the doughs obtained from fermented and sun-dried ahipa starches differed from those of cassava. Sun-light exposure resulted detrimental for the expansion properties of ahipa sour starches, while the native one showed baking expansion properties like those of fermented sun-dried cassava starch.Thus, ahipa starch represents an interesting ingredient for the elaboration of gluten-free baked products.

Technological properties of sour cassava starches: Effect of fermentation and drying processes

Cassava sour starch is a naturally-fermented, sun-dried product. It allows obtaining less dense bakery products than the native starch, being an appreciated gluten-free ingredient. The aim of this work was to study the effect of fermentation and drying method on the physicochemical and technological characteristics of cassava sour starch and to identify the relationships among those distinctive features that may condition their potential food applications.Natural fermentation following starch extraction could not be replaced by the use of a starter. Sour starches pastes showed lower apparent viscosities related to their lactic and/or butyric acid content, and a higher retrogradation tendency, mainly associated to sun-drying. The fermentation combined with the solar exposition represent a complex process that induce changes not easily observed on starch powders but clearly evidenced after gelatinization of the starch suspensions.

Physical and chemical characteristics of cheese bread, using fermented broken rice

Abstract Development of new food products, taking as raw material the subproducts obtained during industrial process become an economic and nutritious alternative, since these are usually discarded, caning be a significant nutritional source good. This research aimed to develop cheese bread using fermented broken rice instead of sour starch in four different concentrations (0%, 25%, 50%, 75% and 100%). After the development of formulations, was performed physics and chemicals characterization of products obtained, performing analysis of: proximate composition, dietary fiber, acidity, pH, oBrix, total soluble sugars, reducing and sucrose. The increased formulations didn’t present significant differences, highlighting the average values of protein 7%, dietary fiber 9% and ash 1.9%. Broken rice, after fermentation process, becomes a profitable alternative instead of the sour starch on cheese breads, saving all the physical and chemical characteristics and being inexpensive.

Potential impacts of bioprocessing of sweet potato: Review

ABSTRACTSweet potato (Ipomoea batatas L.) is among the major food crops in the world and is cultivated in all tropical and subtropical regions particularly in Asia, Africa, and the Pacific. Asia and Africa regions account for 95% of the world's production. Among the root and tuber crops grown in the world, sweet potato ranks second after cassava. In previous decades, sweet potato represented food and feed security, now it offers income generation possibilities, through bioprocessing products. Bioprocessing of sweet potato offers novel opportunities to commercialize this crop by developing a number of functional foods and beverages such as sour starch, lacto-pickle, lacto-juice, soy sauce, acidophilus milk, sweet potato curd and yogurt, and alcoholic drinks through either solid state or submerged fermentation. Sweet potato tops, especially leaves are preserved as hay or silage. Sweet potato flour and bagassae are used as substrates for production of microbial protein, enzymes, organic acids, monosodium glutamate, chitosan, etc. Additionally, sweet potato is a promising candidate for production of bioethanol. This review deals with the development of various products from sweet potato by application of bioprocessing technology. To the best of our knowledge, there is no review paper on the potential impacts of the sweet potato bioprocessing.

Physicochemical transformation of cassava starch during fermentation for production of sour starch in Colombia

This work focused on the study of the physicochemical changes that take place during the fermentation of cassava starch for stepping times of 15–90 days. SEM studies on starch showed special attack while X‐ray diffraction analysis showed that cassava starch is mainly formed by amylopectin and that the acidification process produce significant structural changes in amylose and amylopectin as a function of the steeping time. Module Differential Scanning Calorimetry analysis showed that the acidification process produces an increase in the peak gelatinization for particular steeping times that are directly associated with changes in the acid condition of the samples and re‐crystallization process. Thermogravimetric analysis showed the non‐intentional contamination of the tanks due to the increase in the residue for long steeping times. The periodic reproduction of bacteria in the reservoir govern the changes in the pasting properties of the acid starch.

English

The effects of length of fermentation (5, 10, 15, 20 and 25 days) on pasting properties of sour starches produced from six cassava varieties were investigated. There were significant differences (p < 0.05) in pasting properties except pasting temperature and breakdown viscosity, irrespective of the length of fermentation. Peak viscosity ranged from 308.50 to 466.63 rapid visco unit (RVU), trough ranged from 67.25 to 198.75 RVU, break down ranged from 147.71 to 320.25 RVU, final viscosity ranged from 100.29 to 233.00 RVU, set back ranged from 31.59 to 54.58 RVU, peak time ranged from 3.60 to 4.06 min and pasting temperature ranged from 62.85 to 65.45°C. Sour starches made from TMS 30572, TMS 4(2) 1425 and 96/0603 cassava varieties recorded the highest values. Key words: Cassava, fermentation, pasting, starch, varieties.

Physical, proximate and sensory properties of fortified sour starch bread.

Physical, proximate and sensory properties of fortified sour starch bread.

Caracterização de amidos de mandioca nativos e modificados e utilização em produtos panificados

Cassava starch is used as the main ingredient in the production of biscuits and Brazilian cheese bread. The processing and sale of sour cassava starch - an artisanal product with no established standard of quality - is marked by hygiene problems and its commercial availability is uncertain. The purpose of this study was to characterize native and modified cassava starches and test them in cheese bread and cassava starch biscuit recipes. The main characteristics that differentiate sour starch from native cassava starch are its acidity, degree of expansion, viscosity, clarity of the starch paste, freeze-thaw stability and reducing power. Four different starches were used in the production of baked products: native cassava starch, sour cassava starch, starch modified with hydrogen peroxide and a commercial modified starch named Expandex® 160003. The baked products were evaluated to determine their physicochemical properties and to assess how the different starches affected the products’ internal and external characteristics and flavor. The baked samples were subjected to a sensory analysis of acceptability on a nine-point hedonic scale by untrained tasters. The cheese bread samples containing modified starch oxidized with hydrogen peroxide showed the best results. In the case of the cassava starch biscuits, those made with sour cassava starch and Expandex® 160003 showed the best results, which did not differ statistically.

Physicochemical and Functional Properties of Sour Starches from Different Cassava Varieties

This article reports our investigation on the effect of cassava varieties on the physicochemical and functional properties of sour starches. There were significant differences (P < 0.05) in the ash, pH, amylose, amylopectin, starch damage, total titratable acidity (TTA), sugar, and starch content but not moisture contents of various cassava sour starches. There were no significant differences (P > 0.05) in Water Absorption Capacity (WAC), swelling power, and solubility index, while significant differences were recorded in Least Gelation Concentration (LGC) and color at 5% level and granule size at P < 0.0001 for cassava sour starches. Peak viscosity values ranged from 333.17RVU (clone 4(2) 1425) to 380.75RVU (clone TME 1). There were significant differences (P < 0.05) in pasting properties except for pasting temperature and breakdown.

Anaerobic treatment of cassava starch extraction wastewater using a horizontal flow filter with bamboo as support

Small-scale sour starch agroindustry in Colombia suffer from absence of water treatment. Although starch processing plants produce diluted wastewater, it is a source of pollution and cause environmental problems to the nearby rural population. A laboratory scale anaerobic horizontal flow filter packed with bamboo pieces was evaluated for the treatment of cassava starch extraction wastewater. The wastewater used in the experimentation was the draining water of the starch sedimentation basin. The reactor was operated for 6 months. It was inoculated with a semi-granular sludge from an anaerobic UASB reactor of a slaughterhouse. Maximum organic loading rate (OLR) applied was 11.8 g COD/L d without dilution of the wastewater. At steady state and maximum OLR applied, 87% of the COD was removed and a gas productivity of 3.7 L/L d was achieved. The average biogas yield was 0.36 L/g COD removed. Methane content in the biogas was in the range of 69–81%. The total suspended solids (TSS) removed were 67%. The relative high lactic acid content did not negatively influence the performance of the reactor. No perturbation due to cyanide (3–5 mg/L) was observed during the reactor operation. The results obtained indicated that the anaerobic horizontal flow filter could be used efficiently for the treatment of wastewater from Colombian starch processing small-scale agroindustry.

Characterization and differentiation of Lactobacillus manihotivorans strains isolated from cassava sour starch

Lactobacillus manihotivorans has been reported as one of the dominant species in cassava sour starch production process. Seven isolates that have previously been identified as belonging to this species were studied in the present work. Their molecular and phenotypic characteristics showed higher strain diversity than previously described. Differences were found in their fermentation profiles, whereas no major differences were observed in properties related to processing conditions (salt concentration, pH, temperature), or in potential functional properties (bile salt and pH 2.0 tolerance). Among the main characteristics of interest for the fermentation of cereals or cassava, blended or not with legumes, six out of seven strains were amylolytic and raffinose was fermented by all strains. Strains OND 32 T and OLB 7 fermented the broadest range of carbohydrates. Most of the strains contained plasmids. Plasmid curing changed their phenotypic characteristics, particularly those of strain OND 32 T, which, in addition, lost its starch and raffinose fermentation ability.

Effect of different cultivation conditions on Lactobacillus manihotivorans OND32 T, an amylolytic lactobacillus isolated from sour starch cassava fermentation

Study of the cassava sour starch fermentation has led to the isolation of a new homofermentative amylolytic lactic acid bacterium, Lactobacillus manihotivorans OND32 T, whose nutritional requirements have been investigated in this work. The main effect of deleting one of the substrate components of the MRS-starch medium was to reduce the amylase production. When starch fermentation with nitrogen as a gas phase was compared to fermentation under aerobic conditions, both growth and amylase production were reduced whereas lactic acid formation was not affected. Addition of carbon dioxide (≥20% v/v) to the nitrogen gas phase restored growth and amylase production. The amylase production was high with starch, maltose or cellobiose contrary to glucose, fructose and sucrose. During mixed fermentation of glucose and maltose, a diauxic growth was observed. The maltose consumption and the amylase production started after the glucose depletion. The presence of maltose altered the carbon assimilation from glucose, whereas the energetic pathway was not affected. It is concluded that the elimination of soluble sugars by the wet extraction of starch during the processing of cassava, together with the expected in situ CO 2 production, are conditions favouring the growth and the amylase synthesis. However, these are likely to be limited by the low nitrogen content in cassava.

Molecular Diversity of Lactic Acid Bacteria from Cassava Sour Starch (Colombia)

Lactic acid bacteria and more particularly lactobacilli and Leuconostoc, are widely found in a wide variety of traditional fermented foods of tropical countries, made with cereals, tubers, meat or fish. These products represent a source of bacterial diversity that cannot be accurately analysed using classical phenotypic and biochemical tests. In the present work, the identification and the molecular diversity of lactic acid bacteria isolated from cassava sour starch fermentation were assessed by using a combination of complementary molecular methods: Randomly Amplified Polymorphic DNA fingerprinting (RAPD), plasmid profiling, hybridization using rRNA phylogenetic probes and partial 16S rDNA sequencing. The results revealed a large diversity of bacterial species (Lb. manihotivorans, Lb. plantarum, Lb. casei, Lb. hilgardii, Lb. buchneri, Lb. fermentum, Ln. mesenteroides and Pediococcus sp.). However, the most frequently isolated species were Lb. plantarum and Lb. manihotivorans. The RAPD analysis revealed a large molecular diversity between Lb. manihotivorans or Lb. plantarum strains. These results, observed on a rather limited number of samples, reveal that significant bacterial diversity is generated in traditional cassava sour starch fermentations. We propose that the presence of the amylolytic Lb. manihotivorans strains could have a role in sour starch processing.

Relationship between baking behavior of modified cassava starches and starch chemical structure determined by FTIR spectroscopy

Cassava sour starch is a typical food ingredient from some South American countries, produced mainly in Brazil and Colombia and it shows high expansion when baked. It is known that sun-drying fermented starch is essential. Recently degradative oxidation has been considered as possibly related to chemical changes on cassava starch and was evoked as a probable cause for baking property. We produced some chemically oxidized samples presenting baking property to be compared with lactic acidified and sun- or oven-dried ones, as well as with commercial cassava sour starch and native cassava starch. All the samples were analyzed by using FTIR spectroscopy associated with chemometric data processing. Successful prediction of starch expansion value was achieved by partial least square regression of FTIR spectral data. The results of both qualitative and quantitative spectral analyses showed that presence of carboxylate groups (1600 cm −1) on cassava starch as well as some other changes in the region around 1060 cm −1 of mean normalized spectral data are essential for baking property. The degradative oxidation is assumed to take place on the C–O bond relative to carbon 1 and oxygen 5 of the cyclic part of glucose at 1060 cm −1.

Electrotransformation of Lactobacillus manihotivorans LMG 18010T and LMG 18011

An electroporation procedure was developed for the genetic transformation of intact cells of Lactobacillus manihotivorans, a new Lactobacillus species isolated from cassava sour starch fermentation in Colombia. Transformation efficiency of Lact. manihotivorans strains LMG 18010T and LMG 18011 was measured and compared with electroporability of Lact. plantarum strains NCIMB 8299 and LMG 9211, by investigating the effect of changes in various parameters. For Lact. manihotivorans strain LMG 18010T, the composition of the culture medium, such as the type of peptone and the presence of Tween-80, was found to be the most critical parameter, as well as the aeration conditions of the culture; better electroporation was obtained without air. The presence of MgCl2 in the recovery medium was favourable to regeneration of electroporated cells. Plasmid-curing of the cells did not improve their electroporability. Transformants were obtained with Lact. manihotivorans strain LMG 18010T and the plasmids pLZ12 and pGK13, whereas Lact. manihotivorans strain LMG 18011 was transformable with plasmids pLP825 and pLZ12, with different electroporation conditions.