Lower Final Viscosity Research Articles

Structural characteristics and paste properties of wheat starch in natural fermentation during traditional Chinese Mianpi processing

Fermentation plays a crucial role in traditional Chinese mianpi processing, where short-term natural fermentation (within 24 h) is considered advantageous for mianpi production. However, the influence of short-term natural fermentation on the properties of wheat starch is not explored yet. Hence, structural characteristics and paste properties of wheat starch during natural fermentation were investigated in this study. The findings revealed that fermenting for 24 h had a slight effect on the morphology of wheat starch but significantly decreased the particle size of starch. Compared to native wheat starch, the enzyme activity produced during fermentation may destroy the integrity of starch granules, resulting in a lower molecular weight but higher relative crystallinity and orderliness of starch. After 24 h of natural fermentation, higher solubility and swelling power were obtained compared to non-fermentation. Regarding paste properties, fermented starches exhibited higher peak viscosity and breakdown, along with lower final viscosity, tough viscosity, and setback. Furthermore, the hardness, gel strength, G', and G" decreased after fermentation. Clarifying changes in starch during the short-term natural fermentation process could provide theoretical guidance for improving the quality and production of short-term naturally fermented foods such as mianpi, as discussed in this study.

Hydrogel properties of non-conventional starches from guabiju, pinhão, and uvaia seeds

The physicochemical properties of starch vary depending on the botanical sources, thereby influencing the gelatinisation/retrogradation properties and subsequently affecting the hydrogels characteristics. This study aimed to assess the influence of botanical sources influence on starch and hydrogel properties using non-conventional starch derived from guabiju, pinhão, and uvaia seeds. Hydrogels were prepared by starch gelatinisation followed by 6 h ageing period at room temperature (20 ± 2 °C) and subjected to five freeze–thaw cycles. Pinhão starch exhibited a higher viscosity peak and breakdown, along with a lower final viscosity and setback, compared to guabiju and uvaia starches. The significantly different pasting properties influenced the porous microstructure, water absorption (p-value: 0.01), and resistance of the hydrogels (p-value: 0.01). The guabiju starch hydrogels showed a uniform pore structure without cavities, whereas pinhão and uvaia starch hydrogels exhibited agglomerated and spongy pore structures. Furthermore, the guabiju starch hydrogel demonstrated the lowest water absorption (4.56 g/g) and the highest compression resistance (1448.50 g) among all the studied starch hydrogels. In contrast, the pinhão starch hydrogel showed the highest water absorption (7.43 g/; p-value: 0.01) among all studied starch hydrogels. The hardness of uvaia starch hydrogel did not differ significantly from the guabiju and pinhão starch hydrogel. The different non-conventional starches reveal important variations in the hydrogels characteristics. This provides insights into how amylose and amylopectin interact and present alternatives for using these unique starch-based hydrogels in diverse applications.

Effect of Lactobacillus acidophilus Fermentation on the Quality of Glutinous Rice Products

AbstractThe effect of Lactobacillus acidophilus and spontaneous fermentation on the quality characteristics of glutinous rice products are investigated in this study. Optimization of the product quality based on orthogonal experiments on the four fermentation conditions ensure that the product still has good sensory properties when stored during its shelf life at room temperature. The optimal fermentation conditions based on the range analysis are the mass ratio of glutinous rice, corn and rice 8:1:1, L. acidophilus inoculum of 8%, fermentation temperature of 37 °C, and fermentation time of 28 h. Under this condition, rice products’ hardness, viscosity, elasticity, cohesiveness, and taste significantly increase compared to the spontaneously fermented products. The pasting characteristics, water absorption index, thermodynamic properties, short‐range ordered structure, and microstructure of two kinds of fermented rice flours are analyzed. L. acidophilus fermented rice flour is more prone to pasting and ageing, with a higher proportion of short‐chain amylopectin in starch and lower final viscosity and water absorption, with a denser and smoother internal structure. In conclusion, fermentation improves the properties of glutinous rice flour and its products, and L. acidophilus fermentation is more effective than spontaneous fermentation.

Effect of variation in starch B‐granule content in durum wheat on technological properties and in vitro starch digestion of spaghetti

AbstractBackground and ObjectivesWhile there are a few studies examining the impact of isolated starch A and B granule preparations on cereal end product quality, there is limited information about the effect of genotypic variation in B granule content in starch on pasta technological properties and pasta in vitro starch digestion. Crosses were made between a durum variety Yallaroi and a low and high B‐granule dicoccoides accession and the resulting population evaluated in field trials for starch B‐granule content (S‐BG) and selections made for more detailed analysis.FindingsGenotypes were grouped based on semolina B granule contents of 24.5%−26.7%, 31.7%−37.1%, and 43.9%−45.1% for analysis purposes. Preliminary field data indicated three “43.9−45.1%” B‐granule genotypes had lower grain and test weight and one of these, 156,224*2, a very high semolina Buhler mill yield. Pasta made from the genotypes produced acceptable pasta but there was no association between S‐BG and pasta properties. To overcome protein composition differences between genotypes, starch was isolated and reconstituted flours and pasta prepared. Starch from the same “43.9−45.1%” group all showed RVA profiles with lower final viscosities and setback and displayed higher gelatinization onset and peak temperatures than the “24.5−26.7%” group. Pasta made from reconstituted flours showed similar pasta quality and in vitro starch digestion properties.ConclusionsThe data suggests no relationship between percentage of B‐granules and both pasta quality and starch digestion for the range and populations studied (S‐BG, 22%−44%).Significance and NoveltyThis information provides new insights into the role varying S‐BG content in pasta cooking properties, texture and nutritional characteristics and could provide some direction to breeders to consider breeding for very low or very high B‐granule content.

Effect of zinc-rice grit flour on the physicochemical, nutritional, and sensory properties of gluten-free biscuits

The utilisation of rice flour to produce gluten-free food applications is highly popular as consumers become more aware of celiac disease and safety for baby-led weaning products. The present work investigated the development of gluten-free biscuits made from rice grits flour (RGF).The physicochemical, nutritional, and sensory properties of the products were also evaluated. Rice grits used were from the Inpari 32 and Inpari IR Nutri Zinc types. Results showed that incorporating RGF into biscuit ingredients showed a lot of potential since RGF retained its nutritional value, especially vitamin A and microminerals such as zinc and iron, as well as protein (8.4 - 9.6%), which are all needed to prevent stunting. The Inpari IR Nutri Zinc flour had less amylose (21.12%) and smaller particles than the Inpari 32 flour (amylose: 23.42%) and commercial flour, which resulted in lower hardness level and lower final viscosity. Vitamin A content of biscuits produced from the Inpari IR Nutri Zinc was lower (367 IU/100 g) as compared to the Inpari 32 (412 IU/100 g). The amounts of zinc in the final product were 15 and 12 ppm for the Inpari IR Nutri Zinc and Inpari 32, respectively. Both the Inpari IR Nutri Zinc (19 ppm) and Inpari 32 (73 ppm), which were RGF biscuits, had less iron than commercial biscuit (119 ppm). There were no significant differences among biscuit products in terms of sensory analysis.

Underpinning the soft nature of soak-n-eat rice - A physicochemical and molecular approach

Soak-n-eat rice, a natural treasure of Eastern India, is popular rice based ethnic food item of the tribal peoples of Assam. In the present study, 22 low amylose containing glutinous Bora rice lines were explored for their unique ‘ready-to-eat’ properties, where physicochemical and molecular approach was used to investigate the science behind softness and finally the establishment of trait linked marker associated with this unique soft trait. Very low amylose content, pinholes in kernel, low final viscosity and detection of unique functional groups, made physicochemical properties of soft rice very distinct from normal rice. Polymorphic trait linked markers; a good number of SNPs in trait linked loci and down regulation of those loci during grain filling revealed the unique molecular basis of softness. RM190 is associated with amylose content and softness, confirmed as a trait linked marker by showing heterozygous band in hybrid lines with desired trait. This study may be the first holistic approach on soft rice for its unique soak-n-eat properties and developed hybrid lines may be the source of future environment friendly food.

Monitoring starch hydrolysis with micro visco-amylo-graph for the production of chickpea milk and optimization of the parameters with response surface methodology.

Plant-based milk products are gaining attention since it has been demonstrated that the consumption of animal-derived foods had to be reduced to combat global climate change. The production of plant-based milk includes a starch hydrolysis step for raw materials with high starch content such as cereals and pulses, since the gelatinized starch forms a thick slurry which causes an unsuitable consistency for a drinkable product. The objectives of this work were to investigate the effects of slurry concentration (solid to solvent ratio), enzyme including temperature, enzyme amount and mixing (rotation) speed on the pasting properties especially final viscosity of a crude chickpea milk and also to investigate the potential use of Micro Visco Amylo-Graph for monitoring starch hydrolysis. Response surface methodology, based on Box Behnken Design, was used to assess the parameters and to optimize the hydrolysis conditions for the minimum final viscosity. In conclusion, it was observed that slurry concentration and enzyme including temperature were the most critical factors that affect either the pasting properties or the final viscosity of the crude chickpea milk. Briefly, lower final viscosities were obtained from samples which were prepared at lower beginning concentrations and treated with higher enzyme amounts at lower temperatures.

A novel underutilized starch resource— Lucuma nervosa A.DC seed and fruit

The starch isolated from Pouteria campechiana seeds and pulp is the novel underutilized tropical fruit resource. Pouteria campechiana seed starch (PCSS) had higher amylose content (33.65%), peak viscosity (PV) (4612 cP), breakdown viscosity (BDV) (1993 cP), pasting temperature (Tp) (74.45 °C), gelatinization enthalpy (ΔH) (11.06 J/g), gel adhesiveness (−5.15 g-s), relative crystallinity (Rc) (22.68%), and short-range molecular order (0.740) than Pouteria campechiana pulp starch (PCPS) (16.63%, 4288 cP, 544 cP, 70.95 °C, 8.43 J/g, −10.22 g-s, 17.65%, and 0.675, respectively). Contrastingly, PCSS had lower final viscosity (FV) (3651 cP), setback viscosity (SBV) (1032 cP), gel hardness (173.69 g), water absorption capacity (WAC) (95.21%), and average particle size (7.26 μm) than PCPS (5763 cP, 2019 cP, 243.39 g, 122.86%, and 9.21 μm, respectively). PCSS and PCPS had A-type crystalline structures. A principal component analysis disclosed significantly positive correlations between 1047/1,022, amylose, Rc, Tp, ΔH, and Pt (p < 0.05). Porosity, PV, BDV, FV, gel adhesiveness, gel hardness, and WAC were significantly positively correlated with particle size and SBV whereas 1047/1,022, amylose, Rc, Tp, Pt, and ΔH were significantly negatively correlated with these parameters (p < 0.05). Thus, a theoretical reference for further empirical investigations into P. campechiana fruit and seed starch applications in the food industry has been provided.

Functionality of cassava genotypes for waxy starch

Abstract: The objective of this work was to select cassava (Manihot esculenta) genotypes from the Brazilian germplasm bank with a functionality similar to that of waxy starch. A total of 881 genotypes were pre-selected using principal component analysis and hierarchical clustering, and their industrial potential was compared with that of the 7745-5WX waxy cassava and the WX-Maize waxy maize clones, both used as references. Two genotypes stood out: BGM0036 and BGM0083. Samples from these four genotypes were characterized by means of amylose content, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, paste viscosity, and chain-length distribution of amylopectin. The samples presented A-type crystallinity and no statistical differences (p &gt; 0.05) regarding crystallinity degree (25.3 to 30.0), which shows similar proportions of the amylose/amylopectin fractions. No differences were observed in the microstructure of the cassava starches. Initial gelatinization temperature and amylopectin short chains presented a very strong negative correlation, indicating that a lower proportion of short chains of amylopectin results in a higher initial temperature of gelatinization. BGM0036 and BGM0083 show a low final viscosity, close to that of the waxy maize and cassava starches, being an alternative for use in different foods that require stability during freezing.

Starch Granule Size Distribution and Pasting Characteristic Response to Post-Anthesis Combined Stress of Waterlogging and Shading

The combined stress of waterlogging and shading (WS) caused by continuous rain threatens the production of high-quality weak gluten wheat in China (Triticum aestivum L.). To evaluate its influences on wheat quality formation, Yangmai 158 was chosen to be subjected to WS at 0–7 days after anthesis (DAA, WS0–7), 8–15 DAA (WS8–15), 16–23 DAA (WS16–23), and 24–31 DAA (WS24–31), respectively, with non-stressed plants as control (Non-WS). Compared with Non-WS, WS reduced the amylopectin content and enhanced amylose content in the mature grains. WS enhanced the number and surface but reduced the size of the starch granules. The number, volume, and surface area percentages of B-type starch granules were enhanced, and the number and volume percentages of A-type starch granules were reduced by WS. The peak viscosity and gelatinization temperature were enhanced and the low viscosity and final viscosity were decreased by WS. WS applied at the mid-grain-filling stage (WS8–15 and WS16–23) had greater modification on the starch content, granule size distribution and pasting characteristics than that applied at early (WS0–7) or late (WS24–31). The changes of starch pasting characteristics under WS had a significant correlation with the amylase and amylopectin content, amylase/amylopectin, and the ratio of the volume percent of B-type and A-type starch granules.

Effects of slurry concentration and rotational speeds of drum drier to the characteristics of pregelatinized breadfruit (Artocarpus altilis) flours

Breadfruit is one alternative carbohydrate source in Indonesia. However, breadfruit is seasonal and climacteric crops; it should be processed immediately to produce flour. Native breadfruit flour has many limitations since it is difficult to be solubilized and swollen in cold water. The flour is modified physically by pregelatinization to improve its properties. Pragelatinized breadfruit flour can be used as instant food, porridge, and baby food. This research is aimed to investigate the effect of slurry concentration (20 and 30%) of native breadfruit flour and rotational speeds (4, 6 and 8 rpm) of double drum drier to the chemical composition and physico-chemical properties of the pregelatinized flours. The results showed that pregelatinization did not influence to the chemical composition. Pregelatinization of the flour improved the water solubility and swelling power on room (30°C) and hot (70°C) solutions, reduced the freeze-thaw stability, caused partial gelatinization which is monitored by losing the birefringence of starch granule, and darkened the flour. The pregelatinization also reduced the gelatinization temperature and had low final viscosity. Low concentration of slurry and low rotation speed of drum increased the gelatinized part of the flour, which is influenced to the cold and hot water solubility.

Effect of spray-drying and extrusion on physicochemical characteristics of sweet potato starch.

This study aimed to understand the physicochemical characteristics of sweet potato starch following spray-drying and extrusion processes for desirable applications. Spray-dried starch showed formation of agglomerates and decreased in average granular size from 16.5μm of the native starch granules to 14.1μm. Spray-drying reduced the percentage crystallinity from 25.3 to 22.6% and showed a slight decrease in the molecular weight of amylopectin from 3.1 to 2.6 × 108 gmol-1. In addition, changes in the pasting and gelatinization properties, higher final viscosity (454.4 RVU), and less enthalpy change (8.73Jg-1) were reported after spray-drying. Thus, spray-drying resulted in partially gelatinized starch, which can be selected for making more viscous products. Extruded sweet potato starch displayed an amorphous structure, showed total loss of crystallinity, and significant reduction in molecular weight of amylopectin to 0.41 × 108gmol-1, reflecting complete gelatinization of starch granules during extrusion. Extruded starch showed significant changes in pasting properties, including a display cold viscosity (9.4 RVU). Therefore, extruded starch was suitable for products that require quick solubility and a low final viscosity. Thus, the spray-drying and extrusion processes produce sweet potato starches with particular characteristics that can be used for different and potential applications in industries.

다수성 통일형을 포함한 벼 품종이 쌀미음 품질특성에 미치는 영향

This study was carried out to compare the physiochemical properties and quality characteristics of porridge made from different Korean rice varieties, including high yield tongil-type rice. The rice varieties used in this study were 4 tongil-type (Areum, Namcheon, Hanareum3, Hanareum4) and 5 japonica-type rices (Unkwang, Daebo, Goami4, Dodamssal and Hwaseonchal). The protein and amylose contents of the varieties ranged from 6.0% (Namcheon) to 7.3% (Hanareum3) and from 5.0% (Hwaseonchal) to 42.8% (Dodamssal). Compared to the other varieties, Hwaseonchal and Dodamssal had low final and setback viscosity values in the rapid-visco analyzer test. The color value of the porridge ranged between 52.90 and 71.12 for the L value, -2.06 and -1.01 for the a value, and -5.59 and -2.62 for the b value. SEM images revealed distinct differences in the endosperm structure of rice varieties as well as the porridge. Furthermore, porridge made from Hwaseonchal rice had the highest spreadability, followed by porridge made from others non-glutinous rice varieties, Goami4 rice, and Dodamssal rice. The results of this study suggested that rice varieties with different amylose contents could be effectively used to control the viscosity of rice porridge. In laboratory experiments, the sensory test did not indicate significant differences except for the mouthfeel. The mouthfeel of the porridge depended on the amylose content of rice. This study suggested that tongil-type rice variety such as Hanareum4 could be substituted with Japonica type rice for making porridge.

ВЛИЯНИЕ ШЛИФОВАЛЬНОЙ ПЫЛИ, КАК НАПОЛНИТЕЛЯ КАРБАМИДОФОРМАЛЬДЕГИДНЫХ КЛЕЕВ НА ИХ ТЕХНОЛОГИЧЕСКИЕ СВОЙСТВА

One of the main indicators of the quality of plywood is its environmental friendliness, which is characterized by the content of free formaldehyde. To produce plywood with formaldehyde emission class E0, E1, low-toxic urea-formaldehyde resins should be used. These resins have low final viscosity, which can lead to a decrease in the strength properties of plywood due to excessive penetration of glue into the wood. The viscosity of the working solution of the glue can be changed by the use of fillers (wood flour, rye flour, kaolin, etc.). The results of the research have showed that wood flour has high adsorption capacity and 2-5 m. shares of wood flour increase the viscosity of the adhesive from 60 to 180 s by the VZ-4 viscometer. At the same time, a large amount of grinding dust accumulates in the woodworking shops. To assess the possibility of using grinding dust as a filler of urea-formaldehyde resins, a comparative analysis of the properties of grinding dust obtained by grinding various materials and wood flour in accordance with State Standard 16362-86 has been carried out. The results have showed that grinding dust is comparable to wood flour in moisture, bulk density. The fractional composition of the grinding dust is larger, but most of it corresponds to the necessary fractions of 0.25; 0.18; 0.125 after sorting. The article studies the effect of the fraction and the amount of grinding dust on the strength properties of plywood, as well as on the technological properties of the adhesive (dynamic viscosity, pH, gel time). The maximum increase in the strength of plywood has been 63% when using grinding dust of 0.125 fractions in the amount of 1 m.sh. Adding grinding dust to the adhesive solution leads to an increase in its dynamic viscosity and the larger the particle, the more the viscosity changes. Filling of urea-formaldehyde resins with grinding dust shifts the pH of the adhesive solution towards the neutral and slightly acidic medium and reduces the gelatin time to 55-60 sec. The conducted studies show that the use of grinding dust as a filler of urea-formaldehyde adhesives leads to a decrease in internal stresses in the cured adhesive and an increase in the strength of the gluing of plywood

Starch hydrogels: The influence of the amylose content and gelatinization method

Gelatinization and retrogradation, influenced by amylose and amylopectin ratio, are important characteristics for starch hydrogels elaboration. The objective of this study was to evaluate the influence of amylose content and the gelatinization method on the physicochemical characteristics of native and cross-linked rice starch hydrogels. The native and cross-linked starches were gelatinized with heating or alkaline solution, added polyvinyl alcohol, frozen and then freeze-dried. The cross-linked starch had a low final viscosity (101.38 RVU), which made the heat-induced gelatinized hydrogel readily disintegrated in water. However, modified starch hydrogels obtained by alkaline-induced gelatinization resulted in a more rigid structure than the native starch hydrogels. In addition, the starch sample with high amylose content had lower water absorption (322.2%) due to the greater stiffness of the hydrogel structure that resisted swelling. The alkaline-gelatinization resulted in stiffer hydrogels with lower water absorption (322.2 to 534.8%), while the heat-gelatinized behaved as a superabsorbent (658.7 to 1068.5%). The variability of the hydrogels properties of this study can enable a range of applications due to different amylose contents and gelatinization methods.

Molecular structures and properties of starches of Australian wild rice

Australian wild rices have significant genetic differences from domesticated rices, which might provide rices with different starch molecular structure and thus different functional properties. Molecular structure, gelatinization properties, and pasting behaviours of starch of three Australian wild rices (Oryza australiensis, taxa A (O. rufipogon like) and taxa B (O. meridionalis like)) were determined and compared to domesticated indica and japonica rice. These had higher amylose content, more shorter amylose chains and fewer short amylopectin chains, resulted in a high gelatinization temperature in these wild rices. Compared to domesticated japonica rice, taxa A had a lower pasting viscosity; taxa B had a similar pasting viscosity but lower final viscosity. The significantly different starch molecular structure from that of normal domesticated rices, and concomitantly different properties, suggest advantageous uses in products such as rice crackers or rice pudding, and a source of nutritionally-desirable slowly digestible starch.

English

Weaning food was produced from the blends of sorghum flour, malted sorghum flour and soybean flour. The physicochemical properties of the formulated weaning food were investigated. Flours from three sorghum varieties (local, improved and hybrid sorghum grains) were, respectively, combined with the sorghum malt and soybean flour at different graded levels. The water holding capacity of the weaning food blends ranged between 1.52 and 3.81 ml/g while the viscosity ranged between 14.32 and 33.61 centipoise at 10% (w/v) flour concentration. The least gelation concentration ranged between 8.02 and 20.21 g/ml. The inclusion of sorghum malt in the blends reduced both water holding capacity and viscosity but increased the least gelation concentration. Almost all the pasting variables, except breakdown viscosity, reduced with the inclusion of sorghum malt in the formulations. The range of values for the pasting factors of the weaning food blends include peak viscosity (130.2-532.1 RVU), trough (73.2-335.3 RVU), breakdown viscosity (28.3-97.4 RVU), final viscosity (160.2-826.2 RVU) and setback viscosity (64.1-516.0 RVU). The weaning food blends that could be regarded as appropriate formulation based on the exhibited physicochemical properties are Samsorg 17-(M10) which contained 63, 10 and 27% of raw sorghum flour (RSF), malted sorghum flour (MSF) and soybean flour (SBF), respectively; and Hybrid-(M5) which contained 66.5, 5 and 28.5% of raw sorghum flour (RSF), malted sorghum flour (MSF) and soybean flour (SBF), respectively. Both blends possessed relative low final viscosity, setback value and pasting temperature. Key words: Weaning food, malting, functional properties, viscosity, soybean.

Generating functional property variation in lentil (Lens culinaris) flour by seed micronization: Effects of seed moisture level and surface temperature

The effects of micronization temperature (115, 130, 150 or 165°C seed surface) in combination with lentil (green var. Eston) seed moisture level (natural moisture 8% and tempered to 16 or 23% moisture) on the physico-chemical and functional properties of the resulting flour were investigated. An increase in the water holding capacity of the resulting lentil flour was observed at 16 and 23% seed moisture and micronizing temperatures above 130°C. Higher oil absorption capacity was observed for flours from 16 and 23% seed moisture levels than micronization at 8% moisture. Starch gelatinization was observed only when seeds were micronized at 23% seed moisture level and 18–25% gelatinized starch was found depending on the temperature achieved. Resistant starch percentage and protein dispersibility index of flours decreased with all micronizing temperatures and tempering levels. Endogenous enzyme activities of lentil flour decreased with increasing micronization temperatures as indicated by reduced lipoxygenase and peroxidase activities. The trypsin inhibitory activity was also reduced due to micronization. Differential scanning calorimetry results did not show changes in peak denaturation temperatures for starch and protein except in the flours from micronization treatments above 150°C. However, decreases in the enthalpy values (8–90%) were observed for both starch and protein peaks. Very low final viscosity values were observed for the flours of lentil seed tempered to 23% moisture and micronized to 150 or 165°C surface temperatures indicating possible changes in seed protein and starch. Micronization of tempered lentil seed resulted in changes in functional parameters of the resulting flours thereby allowing entry into different applications than the flour of untreated seeds.

The Physicochemical, Biochemical and Pasting properties of forty one cassava (Manihot esculentaCrantz.) Landraces

Forty one cassava landraces received from CTCRI, Thiruvanathapuram were evaluated for their physicochemical, biochemical and pasting properties to find their industrial applications. In the present study, amylose content ranged between 15.2–32.4 per cent and starch content between 10.8–38.52 per cent. Among the 41 landraces studied, paste clarity was high for nineteen landraces. Swelling of cassava flours increases with increasing temperature and was measured from 50–80°C. Correlation study revealed that the amylose content was positively correlated to starch content and peak viscosity while it was negatively correlated to paste clarity suggesting its importance in food, textile and paper industries. Peak viscosity showed significant positive correlation with BDV, HPV, CPV and SBV. The identified two landraces viz., Manjettan and Thukkuvella 6 possess low amylose content with high paste clarity. The landraces Mysore and Kavaram Kutty recorded high swelling power with high amylose and starch content and the landrace Attukomban had low final viscosity, pasting time with acceptable amylose and starch content. These genotypes are selected for their suitability to food based industries.

Physicochemical properties of taro and maize starch and their effect on texture, colour and sensory quality of tomato ketchup

The physicochemical properties of starch from local cultivar of taro from North‐Eastern region of India, known as Panchamukhi (Colocasia esculenta var. antiquorum) were compared with maize starch. Both starches presented A‐type XRD pattern. The granule size of Panchamukhi taro starch was in the range of 2.19–4.28 µm, which was smaller, compared to maize starch granules (7.38–16.67 µm). Swelling and solubility of Panchamukhi taro starch were found to be higher compared to maize starch. The pasting profile of the starches showed that Panchamukhi starch had lower final viscosity (FV; 2940 cP) and setback viscosity (SV; 826 cP) compared to maize starch (FV of 3878 cP and SV of 1529 cP). The peak gelatinization temperature (Tp) of Panchamukhi taro starch was 74.36°C, which was significantly higher than Tp of maize starch (69.70°C). The incorporation of the starches during preparation of ketchup showed that both starches improved the texture. The colour of the ketchup was not affected by incorporation of starch up to 2% concentration. The sensory evaluation revealed that ketchup prepared using Panchamukhi taro starch was better than the control sample and was comparable to the ketchup prepared using maize starch.