Effect of thermal processing on phenolics, antioxidant activity and health-relevant functionality of select grain sprouts and seedlings

Effects of Lactic Acid Bacteria on Reducing the Formation of Biogenic Amines and Improving the Formation of Antioxidant Compounds in Traditional African Sourdough Flatbread Fermentation

This study investigated the safety and functionality of traditional African sourdough flatbread (kisra), based on the content of biogenic amines (BAs) and antioxidant compounds and their improvement using lactic acid bacteria (LAB) species. The primary BAs detected in naturally fermented kisra were tyramine, histamine, putrescine, and cadaverine, with putrescine being the most abundant after baking. In vitro BA production of microorganisms isolated from kisra sourdough revealed that the Enterococcus genus contributed to tyramine accumulation, whereas presumptive yeasts may contribute to putrescine and cadaverine accumulation. The use of LAB species, including Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Levilactobacillus brevis, and Weissella cibaria, significantly reduced putrescine content to less than about 23% of that of naturally fermented kisra, and eliminated tyramine, histamine, and cadaverine formation. Meanwhile, DPPH scavenging activity, total polyphenolic content, and tannin content in naturally fermented kisra were 85.16%, 1386.50 µg/g, and 33.16 µg/g, respectively. The use of LAB species did not affect the DPPH scavenging activity or tannin content but significantly increased the total phenolic content by up to 20% compared to naturally fermented kisra. Therefore, fermentation with LAB starter cultures might be a promising approach to improve the safety related to BAs as well as the functionality of kisra bread.

Domestic cooking effects on nutritional quality and phytochemical contents of zinc biofortified Lepidium sativum L. sprouts

The impact of the common cooking practices on the nutritional value and the antioxidant contents of Lepidium sativum zinc biofortified sprouts was assessed in the present investigation. Garden cress sprouts showed an increase of dry matter, ash, proteins, carbohydrates, sodium, iron and zinc contents according to the applied cooking process. Antinutrient and pigment contents (chlorophylls, carotenoids and anthocyans) were diminished by applying various cooking treatments. A significant drop of total phenolic (25.57 - 60.87%) and total flavonoid contents (58.04 - 71.86%), catechin hydrate (81.90 - 96.15%), sinapic acid (62.44 - 84.79%), myricitin (97.62 - 99.12%) and rutin (52.83 - 83.41%) was detected in cooked plant material. Nevertheless, cooking practices raised the caffeic acid contents by 21.97 to 29.74% and boil and steam cooking increased the chlorogenic acid amounts by 1.89% and 9.28%, respectively. Microwaving favored an improvement of the antioxidant performances. Overall, Microwaving permitted good nutrients retention along with the best antioxidant performances.

Effect of drying technique on physiochemical and nutritional properties of Eleusine coracana () porridge powder

Eleusine coracana (Finger millet, ragi) is one of the cereals which can cultivate in higher altitudes. This study analysed the effects of various drying techniques such as spray, tray and freeze drying on the retention of micronutrients and structural changes in ragi. Minerals, such as iron and calcium were determined using atomic absorption spectroscopy (AAS) and water-soluble vitamins, such as vitamin B1, B2 and B3 were determined by high-performance liquid chromatography (HPLC). The micronutrient content of freeze-dried ragi powder was observed to be 349.6 ± 0.6 mg/100 g of calcium, 0.550 ± 0.1 mg/100 g of iron, 0.421 ± 0.01 mg/100 g of vitamin B1, 0.193 ± 0.05 mg/100 g of vitamin B1 and 1.103 ± 0.05 mg/100 g of vitamin B3. Along with micronutrients analyses, proximate and various important physiochemical properties were also analysed. Structure analysis of dried ragi using scanning electron microscopy (SEM) indicated that both tray and spray dried ragi show variations in their structure when compared to freeze-dried porridge powder. Crystallisation of starch during drying was determined using Fourier transform infrared (FTIR) spectroscopy. Selected physiochemical properties were also analysed for all dried samples. The results of this study showed that freeze-drying to be the best technique to preserve nutrients over spray and tray drying methods.

Graphical abstract

Impact of Processing and Preservation Methods and Storage on Total Phenolics, Flavonoids, and Antioxidant Activities of Okra (Abelmoschus esculentus L.)

Very few studies have thus far evaluated the impact of various processing and preservation techniques (blanching, frying, freezing, dehydration, and sun drying) on the levels of total phenolics, flavonoids, and antioxidant activities of okra. The primary objective of this study was to evaluate the effects of different processing and preservation methods on the levels of phenolics, flavonoids, and antioxidant activities of okra. The ethanolic extracts of each sample were analyzed before and after preservation and storage for a period of three months. The results showed a significant improvement (p < 0.05) in total phenolic content (134.1 mg GAE/100g) and DPPH (1-1-diphenyl1-2-pricrylhydrazyl) scavenging activity (IC50 value of 3.0 mg/mL) in blanched okra when compared to fresh okra (86.35 mg GAE/100g and IC50 value of 3.8 mg/mL, respectively). Fresh okra exhibited the highest flavonoid content (105.75 mg QE/100g), while sun-dried okra samples stored for three months exhibited a decrease in total phenolic content (14.45 mg GAE/100g), total flavonoid contents (13.25 mg QE/100g), reducing power activity (23.30%), and DPPH scavenging activity (IC50 value of 134.8 mg/mL). The DPPH inhibition activities of all okra treatments showed a significant and positive correlation with the okra phenolic and flavonoid content (r = 0.702 and 0.67, respectively). The reducing power activity (%) of okra treatments exhibited a strong correlation (r) with phenolic contents (r = 0.966), and the correlation with flavonoid contents was 0.459. Generally, different processing and preservation methods of okra revealed that the impact on total phenolic and flavonoid contents, as well as antioxidant activities, was slightly significant among samples preserved using the same method during storage. In addition, blanched and frozen okra resulted in the highest retention of phenolic contents and antioxidant activities.

Assessing the Impact of Roasting Temperatures on Biochemical and Sensory Quality of Macadamia Nuts (Macadamia integrifolia)

Depending on the temperature regime used during roasting, the biochemical and sensory characteristics of macadamia nuts can change. 'A4' and 'Beaumont' were used as model cultivars to examine how roasting temperatures affected the chemical and sensory quality of macadamia nuts. Using a hot air oven dryer, macadamia kernels were roasted at 50, 75, 100, 125, and 150 °C for 15 min. The quantity of phenols, flavonoids, and antioxidants in kernels roasted at 50, 75, and 100 °C was significant (p < 0.001); however, these kernels also had high levels of moisture content, oxidation-sensitive unsaturated fatty acids (UFAs), and peroxide value (PV), and poor sensory quality. Low moisture content, flavonoids, phenols, antioxidants, fatty acid (FA) compositions, high PV, and poor sensory quality-i.e., excessive browning, an exceptionally crunchy texture, and a bitter flavor-were all characteristics of kernels roasted at 150 °C. With a perfect crispy texture, a rich brown color, and a strong nutty flavor, kernels roasted at 125 °C had lower PV; higher oxidation-resistant UFA compositions; considerable concentrations of flavonoids, phenols, and antioxidants; and good sensory quality. Therefore, 'A4' and 'Beaumont' kernels could be roasted at 125 °C for use in the industry to improve kernel quality and palatability.

Novel infrared puffing: Effect on physicochemical attributes of puffed rice (Oryza sativa L.)

The effect of novel infrared (IR) puffing and various IR powers (350, 450, and 550 Watts [W]) at various distances (10, 20, and 30 cm) on physicochemical characteristics of puffed rice (puffing properties, color, total phenolic content [TPC], antioxidant activity, peroxide value, and morphology) was investigated. By reducing the distance and increasing the IR power, the volume puffing was significantly increased (p < .05), and bulk density was significantly decreased (p < .05) but there was no significant difference in the length/breadth ratio. The IR puffing effect on color, the TPC, antioxidant activity, and food compounds' analysis through Fourier transform infrared (FTIR) spectra were significant (p < .05) during IR puffing. The scanning electron microscopy (SEM) images showed that by increasing the IR power and decreasing the sample distance from the IR source, the size of protrusions was increased (the volume of the protrusions). The maximum increase in the protrusions size was observed in 10 cm distance and 550 W power of IR. This is the first report on the IR puffing of rice and according to the results, the IR puffing technology has a high efficiency at the rice puffing.

UHPLC-QTOF-HRMS metabolomics insight on the origin and processing authentication of thyme by comprehensive fingerprinting and chemometrics

The metabolic composition of thyme, one of the most used aromatic herbs, is influenced by environmental and post-harvest processing factors, presenting the possibility of exploiting thyme fingerprint to assess its authenticity. In this study, a comprehensive UHPLC-QTOF-HRMS fingerprinting approach was applied with a dual objective: (1) tracing thyme from three regions of production (Spain, Morocco, and Poland) and (2) evaluating the metabolic differences in response to processing, considering sterilized thyme samples. Multivariate statistics reveal 37 and 33 key origin and processing differentiation compounds, respectively. The findings highlighted the remarkable "terroir" influence on thyme fingerprint, noticing flavonoids, amino acids, and peptides among the most discriminant chemical classes. Thyme sterilization led to an overall metabolite enrichment, most likely due to the facilitated compound accessibility as a result of processing. The findings provide a comprehensive metabolomics insight into the origin and processing effect on thyme composition for product traceability and quality assessment.

Effect of different drying techniques on the nutrient and physiochemical properties of Musa paradisiaca (ripe Nendran banana) powder

Musa paradisiaca (ripe Nendran) is the staple food of south India, especially Kerala. The present study analyzed the effect of different drying techniques, namely, freeze, spray and tray drying on the retention of nutrients especially micronutrients. Mineral content was determined by using Atomic absorption spectroscopy and Vitamin content was determined through High-performance liquid chromatography. This study aimed to analyze the availability of minerals and water-soluble vitamins in dried ripe banana powder. The micronutrient content of freeze-dried banana powder was observed to be with 486.92 ± 0.12 mg/100 g of potassium, 0.60 ± 0.005 mg/100 g of calcium, 3.10 ± 0.10 mg/100 g of sodium, 3.82 ± 0.02 mg/100 g of iron, 6.28 ± 0.04 mg/100 g of vitamin C and 0.606 ± 0.005 mg/100 g of vitamin B6. Along with micronutrient analysis, proximate, and various important physiochemical properties were also analyzed. The results showed that freeze-drying was the best technique to preserve nutrients present in ripe banana. Structure analysis of dried banana was done using scanning electron microscopy indicated that remarkable changes has occurred in both tray and spray dried banana when comparing to freeze dried banana. Data was analyzed by one-way ANOVA, found significantly differ at p < 0.05 with respect to drying methods.

Graphical abstract

The impact of processing on the release and antioxidant capacity of ferulic acid from wheat: A systematic review

The antioxidant capacity and bioaccessibility of ferulic acid (FA)¹ in wheat are highly limited by the lack of free ferulic acid (FFA).² However, many studies claim that wheat processing can efficiently increase FFA content and ultimately influence the overall antioxidant capacity. Hence, this systematic review investigated changes in FFA content, antioxidant capacity and bioaccessibility of wheat after different processing treatments. A literature search of two databases (PubMed and Web of Science) was undertaken covering the last 20 years, yielding 1148 articles. Studies which employed bioprocessing, thermal processing and milling of wheat were considered. After exclusion criteria were applied, 36 articles were included. These covered single processing methods (n = 25, bioprocessing: n = 9, thermal processing: n = 9, milling n = 7) and combined processing methods (n = 11, bioprocessing & thermal processing = 7, bioprocessing, thermal processing & milling = 2, thermal processing & milling = 2). The total ferulic acid (TFA)³ content, degree of covalent bond hydrolysis and the percentage of FFA degraded or transformed to other compounds dominated the final changes in FFA content, antioxidant capacity and bioaccessibility. This systematic review is the first to comprehensively summarize the best efficient processing method for releasing FA and increasing antioxidant capacity and or bioaccessibility in wheat. The combination of particle size reduction, pre-hydrolysis thermal processing (except at high temperature and extended duration) and enzymatic hydrolysis (ferulic acid esterase (FAE)⁴ or fermentation) has the highest potential of releasing FA. However, the literature on the bioaccessibility of FA in wheat is limited and more work is required to demonstrate the link between the release of FA by processing and the consequent health benefits.

Individual or mixing extrusion of Tartary buckwheat and adzuki bean: Effect on quality properties and starch digestibility of instant powder

Introduction

Tartary buckwheat and adzuki bean, which are classified as coarse grain, has attracted increasing attention as potential functional ingredient or food source because of their high levels of bioactive components and various health benefits.

Methods

This work investigated the effect of two different extrusion modes including individual extrusion and mixing extrusion on the phytochemical compositions, physicochemical properties and in vitro starch digestibility of instant powder which consists mainly of Tartary buckwheat and adzuki bean flour.

Results

Compared to mixing extrusion, instant powder obtained with individual extrusion retained higher levels of protein, resistant starch, polyphenols, flavonoids and lower gelatinization degree and estimated glycemic index. The α-glucosidase inhibitory activity (35.45%) of the instant powder obtained with individual extrusion was stronger than that obtained with mixing extrusion (26.58%). Lower levels of digestibility (39.65%) and slower digestion rate coefficient (0.25 min^-1) were observed in the instant powder obtained with individual extrusion than in mixing extrusion (50.40%, 0.40 min^-1) by logarithm-of-slope analysis. Moreover, two extrusion modes had no significant impact on the sensory quality of instant powder. Correlation analysis showed that the flavonoids were significantly correlated with physicochemical properties and starch digestibility of the instant powder.

Discussion

These findings suggest that the instant powder obtained with individual extrusion could be used as an ideal functional food resource with anti-diabetic potential.

The Effects of Fixation Methods on the Composition and Activity of Sea Buckthorn (Hippophae rhamnoides L.) Leaf Tea

Fixation is the key step to improve the quality of sea buckthorn leaf tea. Composition and activity are important indexes to evaluate the quality of sea buckthorn leaf tea. Comparing the effects of fixation methods on components and activities provides a theoretical basis for the contemporary, controllable, and continuous production of sea buckthorn leaf tea. The effects of six different fixed methods, pan-firing fixed (PF), steaming fixed (SF), boiling water fixed (BF), hot air fixed (HF), microwave fixed (MWF), and infrared fixed (IRF) for sea buckthorn leaf tea in terms of α-glucosidase inhibitory activity, lipase inhibitory ability, and the antioxidant capacity were studied. The total flavonoids (TF) content, total soluble phenolics (TP) content, water-soluble carbohydrate (WSC) content, the inhibitory activity of α-glucosidase, lipase inhibitory ability, and the antioxidant capacity of fixed sea buckthorn leaf tea were significantly higher ( $p\le 0.05$ ) compared with sea buckthorn leaf. IRF and MWF samples had higher ( $p\le 0.05$ ) contents of TF (92.48 mg RE/g and 79.20 mg RE/g), TP (115.37 mg GA/g and 135.18 mg GA/g) and WSC (4.24% and 4.39%). The DPPH radical scavenging activity of the SF sample was the strongest one, followed by the MWF sample and IRF sample ( $p\le 0.05$ ). The hydroxyl radical scavenging ability and reducing power of IRF were the strongest one, followed by the MWF sample ( $p\le 0.05$ ). The IRF sample had the strongest α-glucosidase inhibitory activity ( $p\le 0.05$ ), and the MWF sample had the strongest lipase inhibitory ability while samples contained the same amount of total polyphenols ( $p\le 0.05$ ). Principal component analysis results showed that the IRF sample, MWF sample, and SF sample had higher comprehensive principal component values. MWF takes less time than IRF, which operated at 2,450 MHz (full power of 700 W) for 2 min. Therefore, MWF was the most suitable fixation method for sea buckthorn leaf tea. Practical Applications. Leaf tea is the main product of sea buckthorn leaf. However, at present, the quality of sea buckthorn leaf tea in the market is uneven, the processing methods are diverse, and there is no certain quality standard. This paper provides some data support and theoretical support for the production, processing, and purchase of sea buckthorn leaf tea.

Influence of sprouted oat flour substitution on the texture and in vitro starch digestibility of wheat bread

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β-glucan reduced 45 % and polyphenols increased 79 % after sprouting for 120 h.

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Bread’s cell density and specific volume were the highest after sprouting for 72 h.

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The starch digestibility was the lowest with oat flour sprouting for 72 h.

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Two digestible fractions with different digestion rates was presented in the bread.

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Sprouting for 72 h postponed t_2start and reduced digestion rate by 7 % in the bread.

The aim of this study was to investigate the effect of sprouted oats substitutions on the in vitro digestibility of starch in the wheat bread. The physical and nutritional quality of wheat bread enriched with 20 % sprouted oat flour was compared. The polyphenols and γ-aminobutyric acid increased, while the content of starch and β-glucan in the mixed bread was gradually decreased. The specific volume of mixed bread reached the maximum with a 19.79 % reduction of area fraction and a 31.36 % increase cell density when sprouting for 72 h. Two digestible starch fractions with different digestion rates were observed from the LOS-CPS fitted starch digestograms. The microstructure revealed that large type A wheat starch was gelatinized after baking, whereas small type B wheat starch and oat starch were wrapped in protein-β-glucan complexes. This study suggests that properly sprouting has the potential to obtain nutritional bread with low starch digestibility.

Effect of different pretreatments on antioxidant activity of oats grown in the Himalayan region

In this work the different varieties of oats were subjected to three pre-treatments such as germination, sand roasting and γ-irradiation. The pretreated oat grains were evaluated for phenolic content, flavonoid content and antioxidant activity. RP-HPLC displayed that the amount of ferulic acid, chlorogenic acid, kaempferol, ellagic acid and epicatechin in native, roasted and γ-irradiated oats varied in the range of 2.51-3.23, 0.97-1.89, 4.35-5.33, 1.56-2.197 and 3.387-10.8 µg/100 g, respectively. Total phenolic content (TPC) expressed as µg GAE/g and µg FAE/g and total flavonoid content (TFC) expressed as µg rutin equivalent/g was found highest in germinated samples. Study reported increase in antioxidant activity in the following order; γ-irradiation > germination > roasting > native. It was concluded that the different pretreatments enhanced antioxidant properties of the oat grains therefore can be efficiently utilized as food or functional ingredient in various food systems.

Changes in content of bioactive constituents and antioxidant activity of riceberry after food processing and degradation kinetics during storage

The effect of roasting temperature (70, 120, 140°C) and food processing (soaking, steaming, and roasting) on the content of bioactive constituents (total phenolic content, total flavonoid content, total anthocyanin, and γ-oryzanol) and antioxidant activity of processed riceberry were investigated. In addition, the degradation kinetics of bioactive constituents and antioxidant activity during storage were assessed using zero-order and first-order kinetic models. Results showed riceberry roasted at 120°C had the highest total anthocyanin content and antioxidant activity. In addition, riceberry obtained from roasting exhibited the highest bioactive compound and antioxidant activity. Besides, first-order kinetic was confirmed as the best-fitted model to describe degradation of bioactive constituents and antioxidant activity of processed riceberry during storage. This finding suggested that roasting at 120°C was chosen as an optimum condition to maximize the content of bioactive constituents and antioxidant activity and kinetic models provided a better understanding of antioxidant property reduction of processed riceberry during storage. PRACTICAL APPLICATION: Riceberry is an abundant source of bioactive constituents with beneficial health effects leading to a development of functional food product. However, processing may negatively affect biological properties of riceberry and bioactive constituent degradation of processed riceberry during storage has not been previously reported. Therefore, different processes were investigated to determine the effect on bioactive constituents and antioxidant activity of riceberry, and the degradation kinetic model of bioactive constituents during storage was also studied. Optimum processing is appropriate to design riceberry containing high concentration of bioactive constituents and antioxidant activity, which could be considered as a functional diet for health-conscious consumer.

Effects of Roasted Schisandra Chinensis (Turcz.) Baill and Lycium Chinense Mill. and Their Combinational Extracts on Antioxidant and Anti-Inflammatory Activities in RAW 264.7 Cells and in Alcohol-Induced Liver Damage Mice Model

Schisandra chinensis (Turcz.) Baill (SC) and Lycium chinense Mill. (LC) are widely distributed in Asia, where the fruit has traditionally been used for medicinal herbs. We previously reported that the roasting process improved the antioxidant and their hangover relieving effects. In this study, we assessed the antioxidant and anti-inflammatory effects of water extract of SC, LC, and a mass ratio 1 : 1 mixture (SL), after roasting in RAW264.7 macrophage cells stimulated with lipopolysaccharide (LPS). Roasted SL (RSL) extracts showed greater enhancement potential than the others, based on the inhibition of NO (nitric oxide) and intracellular reactive oxygen species (ROS) production in RAW264.7 cells. RSL also significantly decreased the proinflammatory markers (e.g., iNOS, COX-2, TNF-α, and IL-1β) and NAD(P)H oxidase (NOX) signaling proteins (i.e., NOX (-1, -2, and -4), p22^phox, p47^phox, and p67^phox). The inflammatory cytokine, tumor necrosis factor-alpha, interferon-1 beta levels, NF-kB, and mitogen-activated kinase activations were also significantly inhibited by RSL treatment. Based on the results of cellular levels, we compared the promotion effects of RSL extract on liver injury mediated by alcohol-induced inflammation and oxidative stress in mice. Mice were fed a Lieber-DeCarli regular liquid alcohol diet with or without SL and RSL extracts for six weeks. Alcohol intake caused liver injury, evidenced by an increase in serum alanine aminotransferase and aspartate aminotransferase activities. Consistent with the results in cell levels, RSL treatment remarkably downregulated ROS and inflammatory factors, as well as their signaling molecules, in serum and tissues. These results suggest that the roasting of SC and LC could potentially elevate the inhibition effect on alcohol-induced inflammation and oxidative stress and consequently prevent alcoholic liver damage. Also, the combination of SC and LC may provide a more synergistic effect than either alone.

Fruit By-Product Processing and Bioactive Compounds

Total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant potential (FRAP), and diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of avocado peel, avocado seeds, kiwi fruit, orange peel, pineapple peel, and pomegranate skin by-products during processing (i.e., dried, blanched, freezed, and fresh) were determined. It was hypothesized that fruit by-products would add a significant value to the food products. Heat treatments resulted in increasing TPC and TFC and reducing power of fruit by-products with avocado peels TFC of 136.9 and 63.1 mg/100 g of dried and blanched treatments, respectively, compared to 14.4 mg/100 g of fresh and 20.6 mg/100 g of freezed treatments. Orange peels TFC increased from 54.4 mg/100 g of fresh to 194.4 and 380.0 mg/100 g for blanched and dried treatments, respectively. Fresh treatments had the lowest DPPH (%) (IC50), indicating a significant effect of blanching and drying on fruit by-product antioxidant activity with some exceptions. IC50 increased from 20.0 of fresh to 39.8% of dried pineapple peel and from 6.5 to 15.0% for pomegranate skin of fresh and dried treatments, respectively. The use of fruit by-products regardless to its processing as supplements to flours would significantly increase flour’s bioactive availability.

Phenolic Compounds in Whole Grain Sorghum and Their Health Benefits

Sorghum grain (Sorghum bicolor L. Moench) is a staple food grown across the globe, and is mainly cultivated in the semi-arid regions of Africa and Asia. Recently, sorghum grain is increasingly utilized for human consumption, due to the gluten-free nature and potential phenolic-induced health benefits. Sorghum grain is rich in bioactive phenolic compounds, such as ferulic acid, gallic acid, vanillic acid, luteolin, and apigenin, 3-deoxyanthocyanidins (3-DXA), which are known to provide many health benefits, including antioxidant, anti-inflammatory, anti-proliferative, anti-diabetic, and anti-atherogenic activities. Given an increasing trend of sorghum consumption for humans, this article reviews the content and profile of phenolics in sorghum. It covers aspects of their health benefits and explores their mechanisms of action. The impact of thermal processing, such as boiling, steaming, roasting, and extrusion on sorghum phenolics is also discussed. Compelling data suggest the biological functions of sorghum phenolics, however, further investigations appear warrant to clarify the gap in the current research, and identify promising research topics in future.

Quality characteristics of sand, pan and microwave roasted pigmented wheat (Triticum aestivum)

Present study investigated the effect of sand, pan and microwave roasting on physico-chemical, functional and rheological properties of yellow (YW), purple (PW), and black wheat (BW). All roasting methods enhanced the browning index (BI), water absorption capacity (WAC) and oil absorption capacity (OAC) roasted wheat flour. Microwave roasting showed significantly higher impact on BI (58.61% for YW, 131% for BW and 83.85% for PW) and WAC (47.93% for YW, 44.63% for BW and 32.09% for PW). However, the decrease in density, emulsifying capacity (EC), foaming capacity (FC), total phenolic content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC), and antioxidant activity was observed on roasted wheat flour. Roasting also affected the pasting properties of wheat flours and peak, trough, breakdown and final viscosity decreased.

The Effect of Ascophyllum nodosum Extract on the Nutraceutical Antioxidant Potential of Vigna radiata Sprout under Salt Stress

Mung bean (Vigna radiata L.) sprout is a popular fresh vegetable, tasty and high in antioxidants. To increase yield and quality after the occurrence of both abiotic and biotic stresses, the application of seaweed extracts is of great importance. Hence, this study was conducted to determine the effect of Ascophyllum nodosum extract (ANE) in the presence of salt on the antioxidant potential of V. radiata sprouts. Different concentrations of ANE viz. 0.00, 0.01, 0.05, 0.10, and 0.50% and NaCl 0, 25, 50, 75, and 100 mM alone and in combinations were tested for researching the antioxidant potential of V. radiata sprouts at 0, 24, and 36 h of sprouting. The DPPH free-radical-scavenging activity of sprouts of V. radiata was found to increase with time and peaked at 24 h of treatment. The A. nodosum extract (0.01%) could reverse the ill effect of the low level of salinity posed by up to 25 mM NaCl. The increasing salinity deteriorated the antioxidant activity using ABTS method of sprouts down to 20.45% of the control at 100 mM NaCl. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of V. radiata sprouts was found to increase till 36 h of sprouting. A slight increase in TPC, TFC and reducing power was observed when seeds were treated with low concentrations of ANE. The elevation in TPC, TFC and reducing power upon treatment with low concentrations of ANE was also noticed in sprouts in saline combinations. Alpha amylase inhibition activity was found to reach a (67.16% ± 0.9) maximum at 24 h of sprouting at a 0.01% concentration of ANE. Tyrosinase inhibition and alpha glucosidase inhibition was 88.0% ± 2.11 and 84.92% ± 1.2 at 36 h of sprouting, respectively, at 0.01% concentration of ANE. A. nodosum extract is natural, environmentally friendly, and safe, and could be used as one of the strategies to decline stress at a low level and enhance the antioxidant activities in V. radiata sprouts, thus increasing its potential to be developed as an antioxidant-based functional food.

Phenolic Bioactives From Plant-Based Foods for Glycemic Control

Plant-based foods containing phenolic bioactives have human health protective functions relevant for combating diet and lifestyle-influenced chronic diseases, including type 2 diabetes (T2D). The molecular structural features of dietary phenolic bioactives allow antioxidant functions relevant for countering chronic oxidative stress-induced metabolic breakdown commonly associated with T2D. In addition to antioxidant properties, phenolic bioactives of diverse plant foods have therapeutic functional activities such as improving insulin sensitivity, reducing hepatic glucose output, inhibiting activity of key carbohydrate digestive enzymes, and modulating absorption of glucose in the bloodstream, thereby subsequently improving post-prandial glycemic control. These therapeutic functional properties have direct implications and benefits in the dietary management of T2D. Therefore, plant-based foods that are rich in phenolic bioactives are excellent dietary sources of therapeutic targets to improve overall glycemic control by managing chronic hyperglycemia and chronic oxidative stress, which are major contributing factors to T2D pathogenesis. However, in studies with diverse array of plant-based foods, concentration and composition of phenolic bioactives and their glycemic control relevant bioactivity can vary widely between different plant species, plant parts, and among different varieties/genotypes due to the different environmental and growing conditions, post-harvest storage, and food processing steps. This has allowed advances in innovative strategies to screen and optimize whole and processed plant derived foods and their ingredients based on their phenolic bioactive linked antioxidant and anti-hyperglycemic properties for their effective integration into T2D focused dietary solutions. In this review, different pre-harvest and post-harvest strategies and factors that influence phenolic bioactive-linked antioxidant and anti-hyperglycemic properties in diverse plant derived foods and derivation of extracts with therapeutic potential are highlighted and discussed. Additionally, novel bioprocessing strategies to enhance bioavailability and bioactivity of phenolics in plant-derived foods targeting optimum glycemic control and associated T2D therapeutic benefits are also advanced.

Baking Optimization as a Strategy to Extend Shelf-Life through the Enhanced Quality and Bioactive Properties of Pulse-Based Snacks

Food processing optimization can enhance the nutrient bioavailability, storage time, and stability of convenience foods. Baking is a heat and mass transfer process with a high impact on the shelf-life of the obtained product; a small variation in the parameters during baking can lead to significant changes in the end baked product, as it significantly affects the food nutrient profile and bioactive compounds. Response surface methodology (RSM) was used for mapping a response surface over a particular region of interest of baking conditions. The combined effect of the two factors (baking temperature and time) on the selected quality and bioactive parameters as dependent factors was evaluated in order to predict the optimal baking conditions which can facilitate the extended shelf-life of the product through maximizing the antioxidant bioactive properties. This design was used to develop models to predict the effect of the temperature and time baking profile and select those conditions where the quality and bioactive parameters reached a balance to obtain pulse snacks with a high quality, enhanced bioactive properties, and thus a longer shelf-life. Simultaneous optimization by the desirability function showed that a maximum temperature of 210 °C and a time of 14 min were the optimum conditions to produce a pulse-based snack with high antioxidant-antihypertensive activity and nutritional quality.

Orally administered pressure-blanched white saffron (Curcuma mangga Val.) improves antioxidative properties and lipid profiles in vivo

This research focused on studying the effects of orally administered pressure-blanched white saffron on the antioxidative properties and lipid profiles of wistar rats. White saffron was blanched in autoclave for 2.5, 5, 7.5, and 10 min at 100, 105, 110, 115, and 120 °C, which are equivalent to 14.71, 17.53, 20.79, 24.54, and 28.81 psia, respectively. A total of 30 male wistar rats aged four weeks were fed with a standard diet (N), oxidized peanut oil diet + unblanched white saffron (A), oxidized peanut oil diet + blanched white saffron (B), oxidized peanut oil diet + pressure-blanched white saffron (C), and oxidized peanut oil diet + aquadest (NC), for two weeks after pre-treatment with the standard diet for a week. Invivo study showed treatment with pressure-blanched white saffron could significantly improve SOD, Vitamin E, and HDL levels compared to the negative control (NC); 686.44 U/g Hb, 10.87 μg/mL, and 94.17 mg/dL versus 405.37 U/g Hb, 7.44 μg/mL, and 43.47 mg/dL, respectively. Meanwhile, treatment with pressure-blanched white saffron could significantly reduce MDA, total cholesterol, LDL, and triglyceride levels in the blood compared to the negative control (NC); 1.98 mmol/L, 108.74 mg/dL, 40.99 mg/dL, and 78.06 mg/dL versus 8.54 mmol/L, 232.46 mg/dL, 149.17 mg/dL, and 172.61 mg/dL, respectively. The results showed that pressurized blanching could significantly increase antioxidant levels of white saffron, and its dried form could improve antioxidative properties and lipid profiles in vivo.

Application of Autoclave Treatment for Development of a Natural Wheat Bran Antioxidant Ingredient

The study evaluated the effect of autoclaving as a hydrothermal treatment on the quality and bioactivity of wheat bran (WB) with the objective of producing a natural ingredient with enhanced healthy properties. Nutritional, antioxidant, techno-functional and sensorial parameters were studied, and temperatures of 100, 115 and 130 °C were explored. Of these, 130 °C was found to be the best treatment, resulting in an ingredient with high storage stability, antioxidant properties, a four-fold increase in the concentration of free ferulic acid (compared with non-treated WB), and increased content of apigenin-6-C-arabinoside-8-C-hexoside, a flavonoid with reported antioxidant and antifungal properties. On the other hand, the autoclave treatment enhanced water absorption capacity and reduced WB pasting viscosity, mainly at higher temperature (130 °C), which would allow incorporation of the treated WB in liquid matrices such as juices, soups or milkshakes, among others. Although the glycemic index (GI) of the autoclaved samples increased, the use of intermediate particle size of 106 to 300 µm could contribute to the reduction of the glycemic load.

Lignin - An underutilized, renewable and valuable material for food industry

Lignin is the second most abundant biorenewable polymers only next to cellulose and is ubiquitous in various plant foods. In food industry, lignin often presented as a major component of by-products from plant foods. In the last decade, the food and nutritional interests of lignin attracted more and more attentions and great progresses have been accomplished. In the present review, the structure, physicochemical properties, dietary occurrence and preparation methods of lignin from food resources were summarized. Then, the versatile activities of food lignin were introduced under the subtitles of antioxidant, antimicrobial, antiviral, antidiabetic and other activities. Finally, the potential applications of food lignin were proposed as a food bioactive ingredient, an improver of food package films and a novel material in fabricating drug delivery vehicles and contaminant passivators. Hopefully, this review could bring new insights in exploiting lignin from nutrition- and food-directed views.

Comparative study on the phytochemical profiles and cellular antioxidant activity of phenolics extracted from barley malts processed under different roasting temperatures

Consumption of cereal foods has been related to health improvement, which is partly because of their phytochemicals. To explore the functionality and effective application of barley malt, a widely consumed nutritional food, the entire phytochemical profiles and bioactivities of three common barley malt products obtained under different roasting temperatures were analyzed. Results showed that they are abundant in phenolics including flavonoids with high antioxidative activities, as displayed by cellular antioxidant activity (CAA), oxygen radical absorbance capacity, peroxyl radical scavenging capacity, and DPPH and ABTS radical scavenging assays. Among the three barley malts, the raw barley malt bound extract and the dark barley malt free extract exhibited higher CAA values, while the raw barley malt contained a negligible amount of bound phenolics. An efficacious antiproliferation capacity of the dark barley malt free extract was detected in Caco-2 cells. Results also provide an insight into the positive attributes of thermal processing for the biofunctionality of barley malts, especially through the tuning of the accessibility and variability of beneficial phytochemicals.

Characterization of in vitro antioxidant activity, bioactive components, and nutrient digestibility in pigeon pea (Cajanus cajan) as influenced by germination time and temperature

Germination of legumes is potential bioprocessing technique to improve the nutrient digestibility and enhancement of bioactive components. The present investigation studies the effects of different germination conditions on the bioactive components, antioxidant activity, and in vitro nutrient digestibility of pigeon pea. Results obtained indicated that increase in germination time and temperature modifies the bioactive components and nutritional digestibility of the pigeon pea. Studies have shown that increase in germination time from 12 to 48 hr and temperature from 25 to 35°C, results in significant increase in accumulation of total pheolics and flavonoid content as a result of cell wall degrading enzymes. Germination for prolonged time at higher temperature also significantly increases the antioxidant potential and reducing power of the germinated pigeon pea. Increased activity of hydrolytic enzymes alters the structure of starch and proteins and thus enhanced in vitro starch and protein digestibility and also lowers down the hot paste viscosity of germinated pigeon pea. PRACTICAL APPLICATIONS: Currently, consumers are increasingly interested in high-quality natural health foods with high biological value and better nutrient digestibility. Germinated grains legumes become popular among people engrossed in improving and maintaining their health by changing dietary habits. Germinated pigeon pea exhibited better nutrient digestibility with improved texture and flavor, higher antioxidant activity and more bioactive components with lower pasting viscosity due to enzymatic modification of starch and protein in the grain. For this reason, use of germinated pigeon pea flour can provide an excellent example of functional food with high dietary protein value. Germinated pigeon pea flour can be utilized as a functional ingredient in the preparation of novel function foods, and it would intensify metabolism, strengthen immunity, reimburse deficiencies of vitamins and mineral, lower the risk of various diseases and exert health-promoting effects.

Effect of Artificial LED Light and Far Infrared Irradiation on Phenolic Compound, Isoflavones and Antioxidant Capacity in Soybean (Glycine max L.) Sprout

The effect of light emitting diode (LED) light and far infrared irradiation (FIR) on total phenol, isoflavones and antioxidant activity were investigated in soybean (Glycine max L.) sprout. Artificial blue (470 nm), green (530 nm) LED and florescent light (control) were applied on soybean sprout, from three to seven days after sowing (DAS) in growth chamber. The photosynthetic photon flux density (PPFD) and photoperiod was 150 ± 5 μmol m⁻²s⁻¹ and 16 h, respectively. The FIR was applied for 30, 60 and 120 min at 90, 110 and 130 °C on harvested sprout. Total phenolic content (TP) (59.81 mg/g), antioxidant capacity (AA: 75%, Ferric Reduction Antioxidant Power (FRAP): 1357 µM Fe²⁺) and total isoflavones content (TIC) (51.1 mg/g) were higher in blue LED compared to control (38.02 mg/g, 58%, 632 µM Fe²⁺ and 30.24 mg/g, respectively). On the other hand, TP (64.23 mg/g), AA (87%), FRAP (1568 µM Fe²⁺) and TIC (58.98 mg/g) were significantly increased by FIR at 110 °C for 120 min among the treatments. Result suggests that blue LED is the most suitable light to steady accumulation of secondary metabolites (SM) in growing soybean sprout. On the other hand, FIR at 110 °C for 120 min is the best ailment to induce SM in proceed soybean sprout.

Hydrothermal stability of phenolic extracts of brown rice

The phenolics were extracted and purified from brown rice and twenty-seven compounds were identified, including six phenolic acids, four phenolic acid glycosides, and eight flavonoid glycosides. Afterwards, the hydrothermal stability of phenolic extracts of brown rice was investigated after treatment at 60, 80, or 100 °C for 120 min. After hydrothermal treatment, ferulic acid, p-coumaric acid and free glucose were increased, while the phenolic glycosides were decreased. In addition, the total phenolic and total flavonoid content were decreased by 5.7%-9.2% and 3.5%-5.8% after initial 30 min, and then they were slightly recovered after treatment for 120 min. Consequently, there was a slight reduction (<10%) in the total antioxidant activity of the phenolic extracts after hydrothermal treatment. These results suggest that hydrothermal treatment of phenolic extracts of brown rice made some phenolic glycosides deglycosylated, but does not lead to a large reduction in their overall antioxidant activity.

Effect of processing variables on the physico-chemical characteristics and aroma of borş, a traditional beverage derived from wheat bran

Borş is a traditional Romanian beverage obtained by naturally fermenting an aqueous suspension of wheat bran and corn flour, used as flavoring enhancer in local gastronomy since ancient times, and more recently consumed as refreshing drink. To investigate the changes in sensory, physico-chemical, phenolic and aroma composition resulted after two successive fermentations, borș samples were subjected to standard, sensory, HPLC and GC/MS analysis. Total phenolic compounds and ferulic acid, the most abundant phenolic compound, were positively influenced by natural starter addition, increase of fermentation temperature, and thermal treatment, whereas the effect on less abundant phenolic acids was not univocal. The variables had the same effect on antioxidant activity and brown index. Volatiles (alcohols, carboxylic acids, esters), pungent-sour and goat milk-cheese odor notes increased at higher fermentation temperature, whereas bran and yogurt odor notes decreased. The addition of a natural starter at 4 °C allowed balancing odor intensity and antioxidant activity.

Impact on the nutritional attributes of rice bran following various stabilization procedures

Rice bran, a valuable byproduct of the rice milling process, has limitations in food industrial applications due to its instability during storage. This review summaries the methodology for stabilization and its impact on the nutritional properties of rice bran. A variety of treatments have been used and these include heat treatment, low-temperature storage, biological and chemical approaches and these will be discussed in terms of their ability to destroy/inhibit enzyme activity and improve storage performance of rice bran. More importantly, changes in the nutritional value of rice bran in terms of vitamins, polyphenols, tocopherols, flavonoids, free fatty acids caused by stabilization of rice bran will also be discussed. This review highlights the importance of appropriate design of processes for stabilization and controlling storage conditions to ensure quality of the rice bran and enhancing levels of phytochemicals in the bran for novel applications in functional foods.

Changes in Phenolic Acid Content in Maize during Food Product Processing

The notion that many nutrients and beneficial phytochemicals in maize are lost due to food product processing is common, but this has not been studied in detail for the phenolic acids. Information regarding changes in phenolic acid content throughout processing is highly valuable because some phenolic acids are chemopreventive agents of aging-related diseases. It is unknown when and why these changes in phenolic acid content might occur during processing, whether some maize genotypes might be more resistant to processing induced changes in phenolic acid content than other genotypes, or if processing affects the bioavailability of phenolic acids in maize-based food products. For this study, a laboratory-scale processing protocol was developed and used to process whole maize kernels into toasted cornflakes. High-throughput microscale wet-lab analyses were applied to determine the concentrations of soluble and insoluble-bound phenolic acids in samples of grain, three intermediate processing stages, and toasted cornflakes obtained from 12 ex-PVP maize inbreds and seven hybrids. In the grain, insoluble-bound ferulic acid was the most common phenolic acid, followed by insoluble-bound p-coumaric acid and soluble cinnamic acid, a precursor to the phenolic acids. Notably, the ferulic acid content was approximately 1950 μg/g, more than ten-times the concentration of many fruits and vegetables. Processing reduced the content of the phenolic acids regardless of the genotype. Most changes occurred during dry milling due to the removal of the bran. The concentration of bioavailable soluble ferulic and p-coumaric acid increased negligibly due to thermal stresses. Therefore, the current dry milling based processing techniques used to manufacture many maize-based foods, including breakfast cereals, are not conducive for increasing the content of bioavailable phenolics in processed maize food products. This suggests that while maize is an excellent source of phenolics, alternative or complementary processing methods must be developed before this nutritional resource can be utilized.