Understanding the impact of Pulsed Electric Fields treatment on the thermal and pasting properties of raw and thermally processed oat flours

Effect of transglutaminase on the interaction of protein and rice starch

The present study aims to investigate the effects of endogenous protein (rice protein, RP) and exogenous proteins (corn protein, CP, and wheat protein, WP) on the physicochemical properties of rice starch under the action of transglutaminase (TG). The findings indicate that, the interactions between exogenous proteins with rice starch are relatively weak. However, with the catalysis of TG, both endogenous and exogenous proteins tightly encapsulate rice starch granules, forming a dense microporous network structure. This phenomenon led to a reduction in starch expansion coefficient and amylose leaching, resulting in an increase in the onset temperature and a notable decrease in viscosity and digestibility. Among them, endogenous protein exerted the greatest influence on the gelatinization properties of rice starch, whereas exogenous protein had the most significant impact on its digestibility. Specifically, the order of influence on the gelatinization characteristics is RP > CP > WP, and for digestibility, it is WP > CP > RP. Furthermore, under the action of TG, both endogenous and exogenous proteins significantly enhanced the short-range ordered structure of starch molecules, contributing to higher crystallinity and a more ordered A-type structure. In conclusion, this study provides a theoretical basis for the construction of starch functional foods.

Pulsed electric field-induced starch modification for food industry applications: A review of native to modified starches

Starch, a polysaccharide primarily composed of amylose and amylopectin, serves as a critical energy source in plants. However, its native properties often limit its application in the food industry. To overcome these limitations, starch modification is essential for enhancing its technological characteristics. In this context, this review explored the impacts of pulsed electric field (PEF) technology on starch modification. PEF, along with other electrotechnologies, utilizes high-voltage electrical pulses to induce structural and chemical changes in starch granules, leading to improvements in properties such as gelatinization, solubility, viscosity, and swelling capacity. Although PEF is a non-thermal process, it enables significant structural and physicochemical modifications in starch. By avoiding high temperatures that can cause changes in color, flavor, and degradation of essential nutrients, PEF-modified starch results in better preservation of nutritional and sensory qualities, while also enhancing its performance in various industrial processes. Despite its advantages, challenges such as the need for standardized protocols and potential unwanted side reactions at high intensities remain. This review examined the effectiveness of PEF in modifying starch for enhanced technological applications in the food industry, addressing both its benefits and limitations. Additionally, the article provided a foundational overview of starch, including its chemical structure, functionalities, and sources, both conventional and non-conventional, ensuring a comprehensive understanding of how PEF can be applied to optimize starch properties for industrial use.

Ultrasound-assisted modification of oat protein isolates: Structural and functional enhancements

Escalating global protein demand necessitates the commercialization of protein rich products. Oat is a promising high-quality protein source but it requires structural and functional modifications to diversify its application. The current investigation was focused on the impact of different powers of ultrasonic waves (200, 400, and 600 W) on structural and functional characteristics of oat protein isolates to improve its techno-functional properties. Higher strength ultrasound waves generated flat sheet structures which were observed while analyzing microstructure of oat protein isolate (OPI). However, non-significant variation in molecular weight distribution were observed in different treatments. At 600 W power of ultrasonic waves the protein fragments show local accumulation, increased α-helix content. Due to uncoiling of protein structure decrease in β-sheets and β-turns was also observed at 600 W. Protein turbidity decreased significantly under low power ultrasonic treatment (200 W) which significantly increased at higher power. Moderate ultrasonic treatment (400 W) promoted protein dissolution, and maintained a good balance between β-sheets (71.04 ± 0.08), α-helix (16.27 ± 0.02) and β-turns (12.68 ± 0.03), exhibiting optimized flexibility and structural integrity. Whereas, higher strength (600 W) significantly destroyed protein structure. The amino acid content decreased significantly with increasing ultrasonic power. The thermal characteristics of OPI remained unaffected after ultrasound treatment. In conclusion, modifications of secondary and tertiary structure induced by moderate ultrasonic treatment (400 W) improved functional properties of OPI. The 400 W treatment resulted in highest essential amino acid content (EAA) i.e., 22.75 ± 0.82 mg/100 mg and total amino acid content (TAA) i.e., 64.94 ± 2.7 mg/100 mg, which are significantly higher than WHO and FAO standards, suggesting best total and essential amino acid production in comparison to other treatments.

Macrotermes subhylanus flour inclusion in biscuits: Effects on nutritional, sensorial and microbial characteristics

As the world's population expands, edible insects have been proposed as a food source that might address issues related to nutrition, health, the environment, and the economy. This study aimed to create a novel biscuit by adding Macrotermes subhylanus (M. Subhylanus) flour to wheat flour in various concentrations (5,10, 15 and 20 %). The moisture content of the insect composite flours varied between 6.83 % and 7.76 %, whereas the moisture content of the biscuits ranged from 2.86 % to 7.90 %. A significant difference (p < 0.05) was noted in the protein content of both the composite flours and biscuits as the concentration of insect flour increased, with values ranging from 15.03 % to 21.52 % for the flours and 17.38 % to 20.63 % for the biscuits. The lightness (L*) of the composite flours significantly decreased (p < 0.05) with higher additions of edible insect flour, whereas the redness (a*) and yellowness (b*) attributes did not show any statistical differences (p > 0.05). The biscuits were generally darker than the composite flours, as indicated by substantially lower L* values. The water activity of the biscuits was between 0.44 and 0.67. Sensory evaluation revealed that the substitution level (up to 15 %) is ideal for preparing acceptable insect-based biscuits. The panellist perceived no significant differences (p > 0.05) in terms of the texture between the insect-enriched biscuits and the control, except for MZ-20. The absence of pathogenic microogranisms in all baked biscuits containing edible insect flour highlights the effectiveness of heat treatment, ensuring that the biscuits meet microbiological safety guidelines. Additionally, Macrotermes subhylanus flour shows promise as a novel functional ingredient for the food industry.

Structural modification of starch and protein: From the perspective of gelatinization degree of oat flour

To clarify the relationship between gelatinization degree and structure characteristics, oat kernels were roasted to different gelatinization degree of 15 %-90 % based on tempering water content of 22.5 %-35 %, and the structure characteristics of starch and protein were evaluated. The results showed that the increased gelatinization degree dependent on tempering water content promoted protein aggregation on the surface of starch particles, forming larger aggregates with molecular weight >100 kDa. Oat kernels presented a dense starch gel network structure induced by gelatinized starch. Partial gelatinization of starch led to a decrease in pasting viscosities (setback viscosity, 3.91 Pa·s-1.59 Pa·s) and enthalpy (5.12 J/g-0.11 J/g). With the increase of gelatinization degree, the starch crystal structure conversed from A + V type to V type, accompanied by the formation of starch-lipid complexes and a decrease of relative crystallinity (22.28 %-8.72 %). Moreover, 50 % gelatinized oat flour possessed the highest β-sheet structure (38.04 %), but a decrease in surface hydrophobicity and an increase in endogenous fluorescence intensity were found in oat flour of gelatinization degree >50 %. This study provided a theoretical reference for the application of oat flour with different gelatinization degrees to match suitable products.

Red rice starch modification - Combination of the non-thermal method with a pulsed electric field (PEF) and enzymatic method using α-amylase

The objective of this study was to investigate the dual modification of red rice starch using pulsed electric field (PEF) and α-amylase, focusing on morpho-structural, thermal, and viscoamylographic properties. Native starch (Control) underwent various treatments: PEF at 30 kV cm-1 (PEF30), α-amylase at 9.0 U mg-1 (AA0), and a combination of both (PEF30 + α and α + PEF30). The PEF30 + α treatment exhibited the highest degree of digestion (10.66 %) and resulted in morphological changes in the starch granules, which became elongated and curved, with an increased average diameter of 50.49 μm compared to the control. The starch was classified as type A, with a maximum reduction in crystallinity of up to 21.17 % for PEF30. The deconvolution of FT-IR bands indicated an increase in the double helix degree (DDH) for PEF30 and AA0, while the degree of order (DO) was reduced for PEF30, AA0, and PEF30 + α. DSC analysis revealed significant modifications in gelatinization temperatures, particularly for PEF30, and these changes were supported by a reduction in gelatinization enthalpy (ΔH) of up to 28.05 % for AA0. These findings indicate that both individual and combined treatments promote a decrease in starch gelatinization and facilitate the process, requiring less energy. Differences were observed between the formulations subjected to single and alternating dual treatments, highlighting the influence of the order of PEF application on the structural characteristics of starch, especially when applied before the enzymatic treatment (PEF + α). Regarding the viscoamylographic parameters, it was observed that AA0 presented higher values than the control, indicating that α-amylase enhances the firmness of the paste. The double modification with PEF + α was more effective in reducing syneresis and starch retrogradation, leading to improvements in paste properties. This study provided significant insights into the modification of red rice starch using an efficient and environmentally friendly approach.

Structural analysis, nutritional evaluation, and flavor characterization of parched rice made from proso millet

This study investigated the structure and quality characteristics of hard and crispy parched rice obtained from raw proso millet through steaming, roasting, and milling. Results showed that thermal treatment disrupted the structure of samples and transformed the crystal from A-type in raw proso to V-type in parched rice. Rheological and thermodynamic analyses revealed that thermal treatment reduced the stability of parched rice. Gelatinization tests demonstrated that the parched rice was easier to gelatinize and had a lower viscosity. The digestibility of hard parched rice and crispy parched rice improved, with rapidly digestible starch content increasing by 73.62% and 76.95%, respectively, compared with that of raw proso millet. Headspace solid-phase microextraction/gas chromatography-mass spectrometry results further indicated that thermal treatment enhanced the flavor substances of parched rice. These findings demonstrated the unique properties of parched rice and supported its production and processing as a whole grain.

Effect of Pulsed Electric Field Treatment on the Protein, Digestibility, and Physicochemical Properties of Starch Granules in Wheat Flour

The effect of pulsed electric field (PEF) treatment depends mainly on the electric field strength and treatment time. In this study, wheat flour-water suspensions were treated with PEF at an electric field strength of 3 kV/cm for 0 to 1400 pulses to obtain a specific energy input of 0 to 656 kJ/kg. The effect of PEF on the removal or unfolding of proteins from the starch surface, digestibility, starch granule structure, and physicochemical properties of wheat flour was studied. The removal of proteins from the surface and the damage to the internal structure of wheat starch granules after PEF treatment was detected by confocal laser scanning microscopy (CLSM) and FTIR. The damage of the PEF-treated wheat starch granules was observed by scanning electron microscopy (SEM). From CLSM results, penetration of dextran (Mw 10,000 Da) into starch granules of wheat flour was dependent on the energy input of PEF. The high the energy input showed the intense penetration of the biopolymer. The benefits of the accessibility of biopolymer in starch granules are to increase enzyme digestion, especially rapidly digestible starch (RDS). The RDS of wheat flour treated with PEF at 656 kJ/kg was 41.72%, whereas the RDS of wheat flour control was 27.59%.

A comprehensive review on oat milk: from oat nutrients and phytochemicals to its processing technologies, product features, and potential applications

Plant-based milk alternatives have become increasingly desirable due to their sustainability and the increased consumer awareness of health. Among many varieties of emerging plant-based milk, the smooth texture and flavor of oat milk make it spread rapidly around the world. Furthermore, as a sustainable source of diet, oats can provide rich nutrients and phytochemicals. Issues on the stability, sensory properties, shelf life, and nutritional quality of oat milk have been highlighted in published studies. In this review, the processing techniques, quality improvement, and product features of oat milk are elaborated, and the potential applications of oat milk are summarized. Besides, the challenges and future perspectives of oat milk production in the future are discussed.

The Impact of Pulsed Electric Fields on Milk's Macro- and Micronutrient Profile: A Comprehensive Review

Consumers around the world are attracted to products with beneficial effects on health. The stability, functionality, and integrity of milk constituents are crucial determinants of product quality in the dairy industry. Milk contains macronutrients and micronutrients that aid in a wide range of physiological functions in the human body. Deficiencies of these two types of nutrients can confine growth in children and increase the risk of several diseases in adults. The influence of pulsed electric fields (PEF) on milk has been extensively reviewed, mostly concentrating on the inactivation of microbes and enzymes for preservation purposes. Therefore, the information on the variations of milk macro- and micronutrients treated by PEF has yet to be elucidated and it is imperative as it may affect the functionality, stability, and integrity of the milk and dairy products. In this review, we describe in detail the introduction, types, and components of PEF, the inactivation mechanism of biological cells by PEF, as well as the effects of PEF on macro- and micronutrients in milk. In addition, we also cover the limitations that hinder the commercialization and integration of PEF in the food industry and the future outlook for PEF. The present review consolidates the latest research findings investigating the impact of PEF on the nutritional composition of milk. The assimilation of this valuable information aims to empower both industry professionals and consumers, facilitating a thorough understanding and meticulous assessment of the prospective adoption of PEF as an alternative technique for milk pasteurization.

Techno-Functional and Rheological Properties of Alternative Plant-Based Flours

The use of alternative vegetal sources is a proposed strategy to improve the diversity and quality of plant-based products on the market, currently led by soy and pea. This study compares the techno-functional properties of seven vegetable flours (chickpea, lentil, red lentil, white bean, quinoa, amaranth, and oat) and the rheological properties of their flour pastes and gels. All techno-functional properties significantly (α = 0.05) varied depending on the type of flour. Among the flours studied, the highest swelling capacity was for white bean and the lowest for chickpea and red lentil. Water holding capacity was high for white bean and oat flours and low for red lentil. Oat and quinoa flours had the highest oil-holding capacity. Emulsifying and foaming capacities were high for all pulse flours but poor for amaranth and oat flours. However, amaranth and oat provided a much higher viscosity during heating than the rest of the flours. The viscoelastic properties of the flour pastes indicated that they all had a gel structure with storage modulus (G′) values over loss modulus (G″) values. From the viscoelastic properties, amaranth and quinoa showed a weak gel structure with low G′ and G″ values, and the chickpea, lentil, and red lentil formed pastes with a high elastic contribution (high G′ values). In agreement, these three pulse flours were the only ones able to form hard, self-standing gels. These results show the potential of vegetal flours from alternative sources in the development of new plant-based products.

Changes in Starch In Vitro Digestibility and Properties of Cassava Flour Due to Pulsed Electric Field Processing

The research aimed to investigate the effect of pulsed electric field (PEF) treatment on cassava flour at mild intensities (1, 2, and 4 kV/cm) combined with elevated levels of specific energy input (250−500 kJ/kg). Influences on starch digestibility, morphological characteristics, birefringence, short-range order and thermal properties were evaluated. Application of PEF at energy input no greater than 250 kJ/kg had negligible influence on the different starch digestion fractions of cassava flour but raised the rapidly digestible starch fraction at a combined electric field strength >1 kV/cm and energy input >350 kJ/kg. Morphological evaluation revealed that at this PEF combination, cassava starch’s external structure was consistently altered with swelling and disintegration, albeit some granules remained intact. Consequently, this led to disruption in the internal crystalline structure, supported by progressive loss of birefringence and significantly lower absorbance ratio at 1047/1022 cm−1. These physical and microstructural changes of the inherent starch promoted the shift in gelatinization temperatures to a higher temperature and reduced the gelatinization enthalpy. The study demonstrated that PEF can be utilized to change the starch fraction of cassava flour, which is driven by electric field strength and specific energy input, causing changes in the starch-related properties leading to increased digestibility.

Novel nonthermal food processing practices: Their influences on nutritional and technological characteristics of cereal proteins

Cereals, as the main crops cultivated and consumed in the world, are a rich source of carbohydrates, proteins, dietary fiber, and minerals. Despite the nutritional importance, their technological applicability in food matrices is also considerably important to be determined. Cereal processing is done to achieve goals as increasing the shelf-life, obtaining the desired technological function, and enhancing the nutritional value. Nonthermal processing is preferred regarding its potential to provide beneficial impacts with minimum adverse effect. Technological functionality and nutritional performance are considered as the most basic challenges through cereal processing, with proteins as the main factor to take part in such roles. Technological and nutritional functionalities of proteins have been found to be changed through nonthermal processing, which is generally attributed to conformational and structural changes. Therefore, this study is aimed to investigate the impact of nonthermal processing on nutritional and technological characteristics of cereal proteins.

Nonthermal physical modification of starch: An overview of recent research into structure and property alterations

To tailor the properties and enhance the applicability of starch, various ways of starch modification have been practiced. Among them, physical modification methods (micronization, nonthermal plasma, high-pressure, ultrasonication, pulsed electric field, and γ-irradiation) are highly potential for starch modification considering its safety, environmentally friendliness, and cost-effectiveness, without generating chemical wastes. Thus, this article provides an overview of the recent advances in nonthermal physical modification of starch and summarizes the resulting changes in the multi-level structures and physicochemical properties. While the effect of these techniques highly depends on starch type and treatment condition, they generally lead to the destruction of starch granules, the degradation of molecules, decreases in crystallinity, gelatinization temperatures, and viscosity, increases in solubility and swelling power, and an increase or decrease in digestibility, to different extents. The advantages and shortcomings of these techniques in starch processing are compared, and the knowledge gap in this area is commented on.

Non-thermal Technologies for Food Processing

Food is subjected to various thermal treatments during processes to enhance its shelf-life. But these thermal treatments may result in deterioration of the nutritional and sensory qualities of food. With the change in the lifestyle of people around the globe, their food needs have changed as well. Today's consumer demand is for clean and safe food without compromising the nutritional and sensory qualities of food. This directed the attention of food professionals toward the development of non-thermal technologies that are green, safe, and environment-friendly. In non-thermal processing, food is processed at near room temperature, so there is no damage to food because heat-sensitive nutritious materials are intact in the food, contrary to thermal processing of food. These non-thermal technologies can be utilized for treating all kinds of food like fruits, vegetables, pulses, spices, meat, fish, etc. Non-thermal technologies have emerged largely in the last few decades in food sector.