Effects of germination followed by hot air and infrared drying on properties of naked barley flour and starch

Recent advances in germinated cereal and pseudo-cereal starch: Properties and challenges in its modulation on quality of starchy foods

Germination is an environmentally friendly process with no use of additives, during which only water spraying is done to activate endogenous enzymes for modification. Furthermore, it could induce bioactive phenolics accumulation. Controlling endogenous enzymes' activity is essential to alleviate granular disruption, crystallinity loss, double helices' dissociation, and molecular degradation of cereal and pseudo-cereal starch. Post-treatments (e.g. thermal and high-pressure technology) make it possible for damaged starch to reassemble towards well-packed structure. These contribute to alleviated loss of solubility and pasting viscosity, improved swelling power, or enhanced resistant starch formation. Cereal or pseudo-cereal flour (except that with robust structure) modified by early germination is more applicable to produce products with desirable texture and taste. Besides shortening duration, germination under abiotic stress is promising to mitigate starch damage for better utilization in staple foods.

Germination-induced modifications of starch structure, flour-processing characteristics, and in vitro digestive properties in maize

Current research on maize germination suffers from long sampling intervals, and the relationship between the starch structure and the processing properties of flour in maize is still unclear. This study observed the effect of germination on the structure and composition of maize starch and the processing properties of maize flour over a 72 h period using a short interval sampling method. At 36 h, the short-range ordered structure, crystallinity, and enthalpy of starch reached the highest values of 1.02, 34.30%, and 9.90 J/g, respectively. At 72 h, the ratios of rapidly-digested starch (RDS) and slowly-digested starch (SDS) enhanced to 29.37% and 28.97%; the RS content reduced to 35.37%; and the flow properties of the starch were improved. This study enhances the understanding of the effects of germination on the processing properties of maize starch and flour, determines the appropriate application, and recommends the use of germination in the food industry.

Effects of Extrusion Technology on Physicochemical Properties and Microstructure of Rice Starch Added with Soy Protein Isolate and Whey Protein Isolate

In order to improve the retrogradation of rice starch (RS) and the quality of rice products, soy protein isolate (SPI), whey protein isolate (WPI), and rice flour were mixed and further extruded into mixed flour. The physicochemical properties and morphology of starch of extruded rice flour (ERS) and starch of extruded mixtures of SPI, WPI, and rice flour (SPI-WPI-ERS) were analyzed. The distribution of amylopectin chain length, molecular weight, microstructure, crystallinity, short-range ordered structure, pasting properties, and thermodynamic properties of RS, ERS, and SPI-WPI-ERS were measured. The results showed that, compared with rice starch, the proportion of long-chain starch, total starch content, and molecular weight were decreased in ERS and SPI-WPI-ERS, but the proportion of short-chain and amylose content was increased. The short-range order structure was destroyed. The water absorption of ERS and SPI-WPI-ERS was much higher than rice starch at 55 °C, 65 °C, and 75 °C, but lower than that of rice starch at 95 °C. Therefore, the retrogradation characteristics of SPI-WPI-ERS were improved. The setback of rice starch products was reduced and the setback of SPI-WPI-ERS was lower than that of ERS. Overall, the retrogradation of rice starch was delayed by adding exogenous protein and extrusion technology, and the application range of rice flour in staple food products was broadened.

Germination: A Powerful Way to Improve the Nutritional, Functional, and Molecular Properties of White- and Red-Colored Sorghum Grains

This study explored the effects of the germination of red and white sorghum grains (Sorghum bicolor [Moench (L.)]) for up to seven days on various properties of the grain. Germination enriched sorghum's nutritional and sensory qualities while mitigating existing anti-nutritional factors. The study employed Fourier-transformed infrared spectroscopy (FT-IR) and scanning electron microscopy techniques to support its findings. Germination increased protein and lipid content but decreased starch content. White sorghum grains showed elevated calcium and magnesium but decreased iron, potassium, and zinc. Red sorghum grains showed a consistent decrease in mineral content during germination. Germination also increased fiber and lignin values in both sorghum varieties. The results of the FT-IR analysis demonstrate that germination induced significant changes in the molecular structure of white sorghum samples after 24 h, whereas this transformation was observed in red sorghum samples at four days. Total phenolic content (TPC) in red sorghum ranged from 136.64 ± 3.76 mg GAE/100 g to 379.5 ± 6.92 mg GAE/100 g. After 72 h of germination, the germinated seeds showed a threefold increase in TPC when compared to ungerminated seeds. Similarly, the TPC of white sorghum significantly increased (p < 0.05) from 52.84 ± 3.31 mg GAE/100 g to 151.76 mg GAE/100 g. Overall, during the 7-day germination period, all parameters showed an increase, and the germination process positively impacted the functional properties that contributed to the health benefits of white and red sorghum samples.

Effects of explosion puffing on the native structural organization and oil adsorption properties of starch

The effects of explosion puffing (EP) on the native structural organization (i.e., thermal properties, crystalline structure, short-range order, granule morphology and powder properties) and oil adsorption properties of puffed starch (PS) were investigated. The results showed that EP treatment could decrease the melting enthalpy of starch double helices and increase the V-type crystallinity. The highest V-type crystallinity (24.7 %) was obtained when the puffing pressure was 0.4 MPa and the starch:ethanol:water ratio was 1:2:1 (w/w). By controlling the puffing conditions, EP treatment can alter the morphology, and increase the particle size, flowability and specific surface area of PS. The high amorphous proportion and porous sheet structure of PS resulted in the highest oil adsorption capacity when the starch:ethanol:water ratio was 1:1:1 (w/w). Pearson correlation analysis showed that oil adsorption capacity was significantly and positively correlated with the 1022/995 cm-1 value and V-type crystallinity, but negatively correlated with bulk density and angle of repose. Furthermore, oil retention capacity was strongly dependent on V-type crystallinity. These findings demonstrated that EP is an innovative technology with the potential to enhance the V-type crystallinity and adsorption performance of starch.

Effect of malting on physicochemical, antioxidant, and microstructural properties of finger millet (Eleusine coracana) flours

Finger millet (Eleusine coracana L. Gaertn.) is a gluten-free crop with a high amount of fiber, calcium and iron, outstanding malting qualities and a low glycemic index. The study aimed to determine the physicochemical, functional, antioxidant and microstructural properties of malted finger millet (light and dark brown) flours. The two varieties of finger millet grains were germinated for 0, 24, 48 and 72 h and kilned for 8 h. The lightness (L*) values of malted finger millet flours significantly increased, with light brown having the highest L* value of 76.62. The hue angle and total color differences (ΔE) of the malted finger millet flours increased significantly (p ≤ .05.), and values ranged from 63.43° to 71.20° (light brown) and 2.12° to 4.32° (dark brown), respectively. The moisture, ash, fiber, protein, total phenolic, total flavonoids contents and DPPH activity of both malted finger millet flours significantly increased. On the contrary, the fat, carbohydrate, energy contents and FRAP activity significantly decreased with each malting period of both finger millet flours. Both malted finger millet flours' solubility index, water and oil absorption capacity increased significantly while the packed and loose bulk density decreased. Malting had no significant effect on the viscosity of the cold paste; however, a significant decrease in the viscosity of the cooked paste in both finger millet flours was observed, with values ranging from 285 to 424.00 cP (light brown) and 271.33 to 418.00 cP (dark brown), respectively. Malting resulted in changes in the thermal properties of finger millet flours with an increase in the onset, peak and conclusion temperatures. Fourier-Transform Infrared Spectra showed that malting slightly changed the peaks of both finger millet flours. Scanning electron microscopy showed that malting altered the microstructural characteristics of finger millet flours. The results showed that malted finger millet flours are promising raw materials for gluten-free bakery products.

Highland Barley Starch: Structures, Properties, and Applications

Highland barley (HB) is a nutritious crop with excellent health benefits, and shows promise as an economically important crop with diverse applications. Starch is the main component of HB and has great application potential owing to its unique structural and functional properties. This review details the latest status of research on the isolation, chemical composition, structure, properties, and applications of highland barley starch (HBS). Suggestions regarding how to better comprehend and utilize starches are proposed. The amylopectin content of HBS ranged from 74% to 78%, and can reach 100% in some varieties. Milling and air classification of barley, followed by wet extraction, can yield high-purity HBS. The surface of HBS granules is smooth, and most are oval and disc-shaped. Normal, waxy, and high-amylose HBS have an A-type crystalline. Due to its superb freeze-thaw stability, outstanding stability, and high solubility, HBS is widely used in the food and non-food industries. The digestibility of starch in different HB whole grain products varies widely. Therefore, the suitable HB variety can be selected to achieve the desired glycemic index. Further physicochemical modifications can be applied to expand the variability in starch structures and properties. The findings provide a thorough reference for future research on the utilization of HBS.

Elucidation of chickpea hydration, effect of soaking temperature, and extent of germination on characteristics of malted flour

Germination is a biochemical process that has been widely used to improve the nutritional quality, functional properties, and bioavailability of the protein. Soaking is the preliminary step for germination. Effect of soaking temperature on germination parameters was studied to select the suitable soaking temperature for germination. The effect of germination time on nutritional, functional, and microstructural properties of chickpea flour was evaluated. The soaking temperature was selected as 30°C depending on the germination percentage, vigor value, and mean germination time. Physico-chemical composition, antioxidant activity, ascorbic acid, total phenolic, and total flavonoid were investigated over 4 days of germination. It was found that protein content increased on dry matter basis, whereas carbohydrate and fat content decreased during germination. Ascorbic acid content was found to increase to about 3.52 times. Antioxidant activity increased from 24.14% to 58.50% after 4 days of germination. Water absorption capacity was found to decrease, whereas oil absorption capacity increased. XRD pattern depicted a decrease in crystallinity due to the degradation of amylopectin and increased amylose content. SEM was used to study the microstructural changes with increase in germination time. DSC studies were also carried out to study the effect of germination on thermal properties of chickpea flour. PRACTICAL APPLICATION: This research work gives an outline of the available literature on the mechanism of hydration and germination process with the associated chemical and biochemical changes in the bioactive components along with the special emphasis on the health benefits. The present work is an effort toward the development of chickpea-based meal-replacement beverages.

Highland barley starch (Qingke): Structures, properties, modifications, and applications

Highland barley (HB) is mainly composed of starch, which may account for up to 65% of the dry weight to the kernel. HB possesses unique physical and chemical properties and has good industrial application potential. It has also been identified as a minor grain crop with excellent nutritional and health functions. Highland barley starch (HBS) features a number of structural and functional properties that render it a useful material for numerous food and non-food applications. This review summarizes the current status of research on the extraction processes, chemical composition, molecular fine structures, granular morphology, physicochemical properties, digestibility, chemical and physical modifications, and potential uses of HBS. The findings provide a comprehensive reference for further research on HBS and its applications in various food and non-food industries.