Molecular morphology & interactions, functional properties, rheology and in vitro digestibility of ultrasonically modified pearl millet and sorghum starches.

The present research investigated to study the effect of ultrasound treatment on isolated pearl millet starch (PMS) and sorghum starch (SS). Ultrasonication was applied to PMS and SS for 10, 15, and 20 min. Ultrasonically modified pearl millet and sorghum starches evaluated for their techno-functionality, pasting profile, morphology, in vitro starch digestibility, XRD, and molecular interactions. Ultrasound treatment increased water and oil absorption capacity, swelling power, and solubility with treatment time. For ultrasonicated PMS and SS, a significant increase (p < 0.05) in paste clarity (PC) (70.05 % and 67.23 %), freeze-thawing stability (FTS), gel consistency (GC) (25.05 mm and 32.95 mm), and in vitro starch digestibility were observed (57.70 g/100 g and 50.29 g/100 g), whereas no significant changes were recorded for the color values after the ultrasound treatment. Variations in pasting property were also observed in ultrasonicated starches with treatment duration. SEM images confirmed ultrasonication mainly forms pores and indentations on starch granule surface. FTIR spectra and X-ray diffractogram for ultrasonicated starches revealed a slight decrease in the peak intensity and A-type X-ray pattern with lower relative crystallinity (RC) than the native starches. G' > G″ value, indicating the elastic behavior and lower tan δ value, depicting viscous behavior and high gel strength.

Characterization of bioprocessed white and red sorghum flours: Anti-nutritional and bioactive compounds, functional properties, molecular, and morphological features.

In the current investigation, white and red sorghum grains were exposed to bioprocessing techniques, such as soaking, germination, fermentation, and dual processing (both germination and fermentation). Germination and fermentation resulted in improved bioactive profile attributing to better antioxidant activity, whereas a reduction in antinutrient components was observed. On the other hand, soaking had decreased phenolic components and anti-nutritional factors attributing to their leaching in the soaking water. A significant change in the functional properties and color profile was also observed on bioprocessing. It also caused alterations in the morphological structure of the starch-protein matrix and molecular interactions of certain functional groups that reveal the synthesis of certain new bioactive compounds in the flour. The alterations in the bioprocessed flours occurred due to the structural breakdown attributing to the activity of hydrolytic enzymes that were activated during the processing treatments. Bioprocessing was also responsible for the degradation of the starch granules and unfolding of the protein matrix, thus altering the in vitro nutrient digestibility of the flours. Principal component analysis was used to authenticate the differences between different treatments and observations recorded. These bioprocessed flours could be potential ingredients for several valorized cereal products.

Ball-milling: A sustainable and green approach for starch modification.

Ball-milling is a low-cost and green technology that offers mechanical actions (shear, friction, collision, and impact) to modify and reduce starch to nanoscale size. It is one of the physical modification techniques used to reduce the relative crystallinity and improve the digestibility of starch to their better utility. Ball-milling alters surface morphology, improving the overall surface area and texture of starch granules. This approach also can improve functional properties, including swelling, solubility, and water solubility, with increased energy supplied. Further, the increased surface area of starch particles and subsequent increase in active sites enhance chemical reactions and alteration in structural transformations and physical and chemical properties. This review is about current information on the impact of ball-milling on the compositions, fine structures, morphological, thermal, and rheological characteristics of starch granules. Furthermore, ball-milling is an efficient approach for the development of high-quality starches for applications in the food and non-food industries. There is also an attempt to compare ball-milled starches from various botanical sources.

Cereal bar functionalised with non-conventional alfalfa and dhaincha protein isolates: quality characteristics, nutritional composition and antioxidant activity.

The utilization of conventional protein sources like gluten, soy, dairy proteins, and nuts in the development of protein-enriched cereal bars presents a challenge for their consumption by the population suffering from celiac and other food protein allergies. In the present investigation, protein-rich cereal bars were developed using non-conventional protein isolates (alfalfa and dhiancha (API & DPI) and were evaluated for their quality attributes, nutritional composition, and bioactive potential. The incorporation of protein isolates increased the weight, density, and non-enzymatic browning and decreased the water activity in the bars. The hardness of the bar increased with the addition of protein isolates; however, reduced hardness was observed at 7.5 and 10% levels of API. Supplementation with protein isolates enhanced the protein content (7.83-16.71%), total phenols (1642-4956 GAE µg/g), total flavonoids (268-984 QE µg/g), DPPH radical scavenging activity (96.38-114.82 TEAC µmol/100 g) and reducing power (1926-3586 AAE µg/g) of the bars. Cereal bars maintained good sensory score and overall acceptability at 10 and 5% level of incorporation of API and DPI respectively.

Effect of extrusion processing on techno-functional, textural and bioactive properties of whole-grain corn flour-based breakfast cereals sweetened with honey.

The present study investigated the effect of honey and extrusion processing parameters on techno-functional and bioactive properties of whole-grain corn flour breakfast cereals. The central composite rotatable design (CCRD) was used to plan the experiments using feed moisture (FM), extrusion temperature (ET), and honey level as process variables and sectional expansion ratio (SER), bulk density (BD), water absorption index (WAI), water solubility index (WSI), and textural hardness as response variables. The feed containing honey and whole-grain corn flour was extruded through a twin-screw extruder according to CCRD. The data were fit to the appropriate regression models based on model significance and insignificant lack of fit. The selected experiments from CCRD were considered for studying the bioactive properties, and the effect of ET and honey level on bioactive properties was determined. The results of the study indicated that FM and honey adversely affected the SER, BD, and textural hardness, while ET augmented these properties of breakfast cereals. The WAI decreased with an increase in honey level and ET during extrusion. The incremental addition of honey in the mix as well extrusion at elevated temperature led to higher WSI. The whole-grain corn flour added with 10.22% honey and extruded at 16.06% FM, and 138.07°C ET produced optimum quality breakfast cereals with 0.70 desirability. The total phenolic content of breakfast cereals decreased, and antioxidant activity and hydroxymethylfurfural content increased upon extrusion at the higher temperatures. Honey addition lowers the loss of phenolic content during extrusion and improves the antioxidant activity of breakfast cereals.

Enhancement of Digestibility of Nutrients (In vitro), Antioxidant Potential and Functional Attributes of Wheat Flour Through Grain Germination.

Wheat grains were germinated at different time (12, 24, 36, and 48 h) and temperature (25, 30, and 35°C) to enhance the functionality of resultant flour. Results revealed that an increase in germination time and temperature enhanced the in vitro digestibility of starch (10.35-42.30 %) and proteins (6.31-44.02 %) owing to their depolymerization by hydrolytic enzymes. Total phenolic and flavonoid content of wheat during germination at variable conditions were enhanced significantly (p < 0.05) from 3.62 to 5.54 mg GAE/g and 32.06 to 54.33 mg QE/100 g, respectively. Germination at elevated temperature (35°C) for a prolonged time (48 h) increased the DPPH RSA by 58.85 %, reducing power by 80.40 % and metal chelating activity by 112.26 % as a result of the structural breakdown of bound phenolics. Increased activity of hydrolytic enzymes also results in a continuous reduction in the viscosity and lightness values of wheat flour. Tailored germination, therefore, can be offered as a tool to increase the nutrient digestibility and bioactive potential of wheat thus resulting in producing the naturally modified flour with enhanced functionality.