Synthesis, optimization, and characterization of precipitation derived starch nanoparticles from guinea seeds.

Guinea starch nanoparticles (GS-SNP) were developed using ultrasound and nanoprecipitation techniques. The physicochemical, thermal, structural, morphological, pasting, and rheological properties of GS-SNP were examined and compared with native starch. The particle size of GS-SNP was 391.50-206.00 nm, with a PDI of 0.35-0.23 and a zeta potential of -37.5 to -13 mV. The amylose content of GS-SNP increased with a decrease in relative crystallinity, and a VH-type crystalline structure was observed. The GS-SNP were in round shape with some self-aggregated granules. The water and oil absorption capacity, solubility, and gelatinization temperature of GS-SNP increased, but the swelling power was restricted. The viscosity of the GS-SNP dispersion remained almost constant throughout the heating but slightly increased after cooling. A higher degree of shear thinning was observed due to a fluid-like gel network and weak gel structure. The optimum conditions were: 50 % amplitude, 30 min time, and a starch to ethanol ratio (1:4) with 85 % maximum desirability. Overall, the findings suggest that GS-SNP have promising potential for application in a liquid system where viscosity of the system cannot be significantly influenced by temperature.

Effect of sorghum pre-processing (roasting and germination) on the replacement level and quality of sorghum-wheat bread: bread characteristics, digestibility, consumer acceptability and microbiological analysis.

Abstract: The present study was focused on the replacement of refined wheat flour (RWF) by control (CS) and processed sorghum flour [germinated (GS) and roasted (RS)] on the properties of flour/batter/dough (particle size, XRD, pasting, dynamic rheology, farinograph) and bread (physical, textural, digestibility, microbiological and sensory). Prominent variations adhered with sorghum processing, but decreasing patterns occurred for flour-water absorption, dough stability times, storage modulus, peak/final/breakdown viscosities, bread-moisture content, specific volume, porosity, and lightness. Flour's pasting temperature, dough development time, breadbulk density, hardness, gumminess, and bitterness increased. Composite flours mainly had weak nature compared to RWF. The baking loss was lower for 10-30% CS and GS incorporation than RS. Composite bread had higher in-vitro protein and starch digestibility (CS > GS > RS) than RWF. Three days storage life with acceptable quality scores was obtained for bread with CS and GS up to 20% and RS up to 30% incorporation. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05810-3.

Influence of convective hot air drying on physico-functional, thermo-pasting and antioxidant properties of elephant foot yam powder (Amorphophallus paeoniifolius).

The present study focused on the effect of different drying temperatures (40, 50, 60 and 70 °C) and combination of pre-treatments: potassium metabisulphite (KMS), potassium metabisulphite + Citric acid + blanching (KCB)] on functional, thermo-pasting and antioxidant properties of elephant foot yam (EFY) powder. Drying temperature and pretreatment reduces the water and oil absorption capacity, and the highest values were 2.34 g/g and 1.19 g/g for drying at 40 °C for the untreated sample, respectively. KMS pretreatment enhanced the bulk density, foaming capacity, emulsion capacity, and emulsion stability with an increase in drying temperature. Pasting temperature and viscosity decreased with an increase in drying temperature, and the maximum was observed at 40 °C for KMS pretreatment. Blanching increases the gelatinization temperature resulting in higher mid-and end-temperatures for KCB pretreatment. The antioxidant properties decreased with an increase in the drying temperature and were found to be minimal in the case of KCB treated samples.

Bread preparation by partial replacement of wheat by germinated sorghum.

Published literature shows significant impact of sorghum type and flour on end-product quality, while demonstrating paucity in the studied varieties with respect to processing aspects (such as bread making) despite of enormous accessions available worldwide. Limited studies have reported usage of germinated flour for the above said purpose. The present study thus aimed at mitigating these gaps by utilizing results of sorghum (HJ-513) germination (Day 1-5) and flour derived from optimized condition (Day 3 as identified by partial least square analysis) to develop a composite functional bread (partial replacement of wheat). The germination process enhanced the total phenolics compounds (TPC, till day 3), water (14.01%) and oil absorption capacity (25.97%) while reducing the bulk density (760.99-644.69 kg/m3). This demonstrated increased potential of sorghum flour for development of bakery and confectionery products. The process also affected the pasting properties, total flavonoids compounds (TFC) and DPPH (2, 2-diphenyl-1-picrylhydrazyl) significantly (p < 0.05). The bread developed from partial replacement (10% and 20%) of refined wheat flour by sorghum was hard and darker than the control wheat bread. The bread developed at 20% was more dense and porous than the bread developed with 10% replacement. Specific volume of bread at 10% replacement was found higher than at 20% replacement. The study reports effective utilization of germinated sorghum flour for development of composite-functional bread without incorporation of any other additives/improvers. Future research however is warranted in the field to further increase the replacement of wheat flour by germinated sorghum flour to develop gluten free bread.

Optimization of the frying process in relation to quality characteristics of Khaja (A traditional sweet).

The present study was focused on the optimization of process parameters and quality characterization of Khaja. A full factorial design 53 was applied using different levels of fat proportions (5-25%), frying temperature (160-200 °C), and frying time (1-5 min). The response optimizer function in Minitab 18 software was used to select five samples with the highest desirability which were then subjected to sensory analysis. The lightness of the samples decreased significantly (P ˂ 0.05) from 68.59 to 43.33 whereas, redness increased significantly (P ˂ 0.05) from 0.26 to 11.48 with increasing levels of all independent variables. Water activity and moisture content of the samples decreased significantly (P ˂ 0.05) from 0.75 to 0.21 and 14.41-1.40%wb respectively, whereas total fat content increased significantly (P ˂ 0.05) from 25.05 to 45.7% with increasing levels of independent variables. The hardness of the samples significantly (P ˂ 0.05) varied from 60.45 to 7.69 N. The sensory analysis revealed that the sample with 20% fat proportion, fried at 180 °C for 4 min, scored maximum in overall acceptability. The microstructural images revealed the structural damage and formation of pores in fried samples. The fatty acid analysis showed higher saturated fatty acids in market samples than in optimized samples. The results of the study concluded that fat proportion and frying parameters (temperature and time) are crucial for a better understanding of the deep-frying process of Khaja in order to achieve good quality. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05509-x.

Gluten-free grains: Importance, processing and its effect on quality of gluten-free products.

Gluten-enteropathy affects a significant number of people, making gluten a major concern in the food industry. With medical advancements, the diagnosis of allergies is becoming easier, and people who are allergic to gluten are recommended a complete gluten-free diet. Since wheat provides a major part of the energy and nutrition in the diet, its elimination affects nutrition intake of allergic population. Food scientists are working to formulate products using protein-rich gluten-free grains with quality attributes at par with gluten-containing products. Focused research has been done to provide nutrition and a variety of food to people suffering from gluten-related disorders. Efforts are being made to remove the gluten from the wheat and other gluten-containing grains, while applying different processing/treatments to enhance the properties of gluten-free grains. Hence, the present review summarizes the importance, processing, and products of different gluten-free grains. It also highlights the digestibility of gluten-free grains with clinical trials and gluten elimination strategies for gluten-containing grains.

Quality attributes of convective hot air dried spine gourd (Momordica dioica Roxb. Ex Willd) slices.

In the present study, spine gourd slices were dried in a convective dryer at 40, 50, 60 and 70 °C temperature. The change in quality of spine guard was determined by analyzing the change in proximate, minerals, functional group, chlorophyll, ascorbic acid, and antioxidant characteristics. Increase in drying temperature changed the protein (4.62-12.88 g/100 g), fiber (3.14-3.53 g/100 g), total phenolic (14.85-14.99 mg gallic acid equivalent/g) and total flavonoid (30.1-64.8 mg quercetin equivalent/100 g) content while reduction occurred in fat (4.02-3.07 g/100 g), carbohydrate (76.13-55.22 g/100 g), chlorophyll (0.34-0.100 mg/g), ascorbic acid (29.94-4.50 mg/100 g) and antioxidant activity (96.58-85.06%). Mineral content of fresh SG differed significantly with dried samples (p < 0.05), while variable effects were associated with the change in drying temperatures. Changes in functional groups were analyzed by Fourier transform infrared spectrophotometer. The observed parameters were optimized using principal component analysis. The sample dried at 40 °C was superior in quality whereas higher protein and antioxidants were found at 70 °C.

Ultrasound assisted extraction (UAE) of bioactive compounds from fruit and vegetable processing by-products: A review.

Growing fruit and vegetable processing industries generates a huge amount of by-products in the form of seed, skin, pomace, and rind containing a substantial quantity of bioactive compounds such as polysaccharides, polyphenols, carotenoids, and dietary fiber. These processing wastes are considered to be of negligible value compared to the processed fruit or vegetable due to lack of sustainable extraction technique. Conventional extraction has certain limitations in terms of time, energy, and solvent requirements. Ultrasound assisted extraction (UAE) can extract bioactive components in very less time, at low temperature, with lesser energy and solvent requirement. UAE as a non-thermal extraction technique is better equipped to retain the functionality of the bioactive compounds. However, the variables associated with UAE such as frequency, power, duty cycle, temperature, time, solvent type, liquid-solid ratio needs to be understood and optimized for each by-product. This article provides a review of mechanism, concept, factor affecting extraction of bioactive compounds with particular focus on fruit and vegetable by-products.

Advances in application of ultrasound in food processing: A review.

Food processing plays a crucial role in coping up with the challenges against food security by reducing wastage and preventing spoilage. The ultrasound technology has revolutionized the food processing industry with its wide application in various processes, serving as a sustainable and low-cost alternative. This non-destructive technology offers several advantages such as rapid processes, enhanced process efficiency, elimination of process steps, better quality product and retention of product characteristics (texture, nutrition value, organoleptic properties), improved shelf life. This review paper summarizes the various applications of ultrasound in different unit operations (filtration, freezing, thawing, brining, sterilization/pasteurization, cutting, etc.) and specific food divisions (meat, fruits and vegetables, cereals, dairy, etc.) along with, the advantages and drawbacks of the technology. The further scope of industrial implementation of ultrasound has also been discussed.

Physico-functional and structural characterization of ultrasonic-assisted chemically modified elephant foot yam starch.

Limited studies are present on dual modification of elephant foot yam (EFY) starch and no study investigated the combined effect of citric acid (CA) and ultra-sonication (US). In the present study, EFY starch was subjected to different concentrations of CA with and without US. Changes in different properties such as functional, morphology, thermo-pasting etc. were examined. Both treatments increased the water and oil absorption capacity of starch. Pasting properties significantly (p < 0.05) reduced with US modification, except pasting viscosity and pasting temperature. CA modification decremented the glass transition temperature which further reduced with US. Starch morphology revealed aggregation of individual granules upon CA modification whereas CA + US broke the aggregates and caused surface fissures and cracks. Overall crystallinity enhanced with an increase in the citric acid concentration. Changes in functional groups identified by FTIR analysis showed new peak formation (1710-1690 cm-1) associated with CA modification. The results showed that CA and CA + US changed the functionality, morphology and other structural characteristics of EFY starch which enable us to use the modified starch in the range of application i.e. bakery products, extruded products, thickening agent and other.

Effect of microwave treatment (low power and varying time) on potato starch: Microstructure, thermo-functional, pasting and rheological properties.

The present study focused on the effect of microwave treatment (300 W for 1, 3 and 5 min) on the physicochemical, morphological, structural and rheological properties of potato starch. Significant effect (p < 0.05) of treatment time was observed on water activity and moisture content while non-significant effect occurred on color. Water absorption capacity increased from 0.82-1.16 g/g with treatment time while oil absorption capacity decreased from 0.63-0.53 g/g. Dynamic and loss moduli, pasting temperatures and final viscosities were positively correlated with treatment time. The peak and pasting viscosity incremented till 3 min treatment but decreased at 5 min. Onset temperature of gelatinization ranged from 53.8 to 57.4 °C with treatment time. SEM micrographs showed unaffected starch granules at 1 min of treatment while fissures and indentations developed at 3 and 5 min. The X-Ray diffraction patterns indicated the transformation of starch crystals from B crystallite to amorphic type.

Development and characterization of elephant foot yam starch-hydrocolloids based edible packaging film: physical, optical, thermal and barrier properties.

The study aimed at the development of elephant foot yam starch (EFYS) based edible film through blending of Xanthan (XG) and agar-agar (AA). Film thickness and density increased with increase in concentration of hydrocolloids and the respective highest value 0.199 mm and 2.02 g/cm3 were found for the film possessing 2% AA. The film barrier properties varied with hydrocolloids and the lowest value of water vapour transmission rate (1494.54 g/m2) and oxygen transmission rate (0.020 cm3/m2) was observed for the film with 1% XG and 1.5% AA, respectively. Mechanical and thermal properties also improved upon addition of hydrocolloid. Highest tensile strength (20.14 MPa) and glass transition temperature (150.6 °C) was observed for film containing 2% AA. Fourier transform infrared spectroscopy demonstrated the presence of -OH, C-H, and C=O groups. The change in crystallinity was observed through peak in X-ray diffraction analysis, which increased with increase in the hydrocolloids' concentration.

Influence of xanthan and agar-agar on thermo-functional, morphological, pasting and rheological properties of elephant foot yam (Amorphophallus paeoniifolius) starch.

Limited studies have been reported on the interaction of elephant foot yam (EFY) starch and hydrocolloids. Hence the present study investigated the effect of hydrocolloids (agar-agar, AAG and xanthan gum, XG) concentration (0.5, 1, 1.5 and 2%) on pasting, rheological, thermo-functional and morphological properties of EFY starch. The increase in concentration reduced the swelling index and enhanced the solubility. Peak, holding, break down and set back viscosity was highest at 2% XG than AAG. Dynamic storage modulus (G') was higher than loss modulus (G″) within frequency range with an increase in hydrocolloids concentration. Pasting temperature reduced from 77.20 to 49.7 °C (AAG) and 77.20 to 61.56 °C (XG). FTIR exhibited differences in peak absorbance and broadness of OH and CO stretching at 3400-3200 cm-1 and 1260-1000 cm-1 upon hydrocolloids' addition. Increased AAG concentration reduced the peak temperature of gelatinization and retrogradation of EFY starch. The effect of hydrocolloids and their concentrations on the higher binding of EFY starch molecules and crystallinity has also been supported by SEM images. These results show that EFY starch with hydrocolloids can be used as a thickener. Its good binding ability may be explored for the possible applications in bakery industry and for the development of edible packaging film.

Physico-functional and antioxidant properties of sand-roasted chickpea (Cicer arietinum).

The effect of roasting on the physical, color, thermal, functional and antioxidant properties of chickpea was investigated. Chickpea grains were roasted in sand at three temperatures (180, 200 and 220°C) for different times (5, 10 and 15min). Highest surface area and lowest bulk density were obtained for grains roasted at 220°C for 15min. The lightness 'L' of flour decreased from 88.48 (unroasted) to 78.73 (220°C, 15min) while significant increase in 'a' and 'b' color values was observed from -0.73 to 2.25 and 22.43 to 24.83, respectively on roasting. Significant decrease in enthalpy of gelatinization (-0.14 to -0.46J/g), enthalpy of amylase-lipid complex (4329-2293J/g), total flavonoid content (22.89-16.64mg quercetin equivalents/100g) and antioxidant activity (22.85-7.36%) was observed upon roasting. However, roasting led to an increase in water absorption capacity (0.89-3.64g/g), water absorption index (1.97-3.52) and oil absorption capacity (1.60-3.54g/g).