Effect of extrusion on phytochemical profiles in milled fractions of black rice

Transforming oilseed blends: the impact of low-moisture extrusion on antinutritional factors, protein structure, and nutritional value

Oilseed cakes from hemp, rapeseed, and flaxseed are protein-rich, sustainable sources but are limited in food applications by antinutritional factors. This study blended meals from these oilseeds with pea or hemp protein ingredients (50:50 w/w) and applied low moisture extrusion (10 % and 20 %) at 122 °C to investigate their impact on physicochemical characteristics of oilseeds blends. Extrusion preserved protein content, reduced protein solubility by up to 44.5 %, and improved in vitro digestibility by up to 13.5 %. Antinutritional factors, including polyphenols (-10.18 % to -52.80 %), saponins (-4.48 % to -21.31 %), condensed tannins (-20.37 % to -41.05 %), and trypsin inhibitors (-2.26 TIU/mg to -13.31 TIU/mg), were significantly reduced, though phytic acid content was less affected. Extrusion decreased surface hydrophobicity, disrupted protein-protein interactions, altered secondary structures, and retained protein profiles under reducing conditions. These findings provided valuable scientific insights into the application of extrusion in enhancing nutritional value and modifying structure of plant-based meat alternatives.

Research Progress on the Physicochemical Properties of Starch-Based Foods by Extrusion Processing

Extrusion is a crucial food processing technique that involves mixing, heating, shearing, molding, and other operations to modify the structures and properties of food components. As the primary energy source material, the extrusion process induces significant physical and chemical changes in starch that impact the quality of final products. This review paper discusses novel technologies for starch extrusion and their influence on the physical and chemical properties of starch-based foods, such as gelatinization and retrogradation properties, structural characteristics, and digestion properties. Additionally, it examines the application of extrusion in starch processing and the interactions between starch and other food components during extrusion. This information sheds light on the structural and property alterations that occur during the extrusion process to create high-quality starch-based foods.

NaCl Stress Stimulates Phenolics Biosynthesis and Antioxidant System Enhancement of Quinoa Germinated after Magnetic Field Pretreatment

Our previous study showed that magnetic field pretreatment promoted germination and phenolic enrichment in quinoa. In this study, we further investigated the effects of NaCl stress on the growth and phenolic synthesis of germinated quinoa after magnetic field pretreatment (MGQ). The results showed that NaCl stress inhibited the growth of MGQ, reduced the moisture content and weight of a single plant, but increased the fresh/dry weight. The higher the NaCl concentration, the more obvious the inhibition effect. In addition, NaCl stress inhibited the hydrolysis of MGQ starch, protein, and fat but increased the ash content. Moreover, lower concentrations (50 and 100 mM) of NaCl stress increased the content of MGQ flavonoids and other phenolic compounds. This was due to the fact that NaCl stress further increased the enzyme activities of PAL, C4H, 4CL, CHS, CHI, and CHR and up-regulated the gene expression of the above enzymes. NaCl stress at 50 and 100 mM increased the DPPH and ABTS scavenging capacity of MGQ and increased the activities of antioxidant enzymes, including SOD, POD, CAT, APX, and GSH-Px, further enhancing the antioxidant system. Furthermore, principal component analysis showed that NaCl stress at 100 mM had the greatest combined effect on MGQ. Taken together, NaCl stress inhibited the growth of MGQ, but appropriate concentrations of NaCl stress, especially 100 mM, helped to further increase the phenolic content of MGQ and enhance its antioxidant system.

Extrusion treatment of rice bran insoluble fiber generates specific niches favorable for Bacteroides during in vitro fermentation

To investigate the morphological changes of insoluble fiber and their effects on microbiota modulation, particularly Bacteroides, rice bran insoluble fibers were extruded at different feed moisture levels (E20, E40, and E60). The physicochemical properties and SEM revealed that E20 exhibited the highest water holding capacity and displayed the most fragmented edges. E40 had the highest swelling holding capacity and displayed the most lamellar gaps. E60 showed minimal change in physicochemical properties but had a rough surface. After 48h fermentation, E40 showed the highest levels of Bacteroides and SCFAs. E20 and E60 resulted in a modest increase in Bacteroides abundance. SEM showed that bacteria were attached to fragmented edges, loosened lamellar gaps, and rough surfaces of the extruded insoluble fibers. The results suggested that Bacteroides gained a competitive advantage within the extrusion treatment created structural changes. Extrusion treatment can be used to generate specific niches favorable for Bacteroides.

Effect of Sprouted Buckwheat on Glycemic Index and Quality of Reconstituted Rice

This study utilized sprouted buckwheat as the main component and aimed to optimize its combination with other grains to produce reconstituted rice with enhanced taste and a reduced glycemic index (GI). The optimal blend comprised wheat flour, sprouted buckwheat flour, black rice flour, and purple potato flour in a ratio of 34.5:28.8:26.7:10.0. Based on this blend, the reconstituted rice processed through extrusion puffing exhibited a purple-black hue; meanwhile, the instant reconstituted rice, produced through further microwave puffing, displayed a reddish-brown color. both imparted a rich cereal flavor. The starch in both types of rice exhibited a V-shaped structure with lower relative crystallinity. Compared to commercial rice, the reconstituted rice and instant reconstituted rice contained higher levels of flavonoids, polyphenols, and other flavor compounds, along with 1.63-fold and 1.75-fold more proteins, respectively. The GI values of the reconstituted rice and the instant reconstituted rice were 68.86 and 69.47, respectively; thus, they are medium-GI foods that can alleviate the increase in blood glucose levels.

Plant-Wide Target Metabolomics Provides a Novel Interpretation of the Changes in Chemical Components during Dendrobium officinale Traditional Processing

The traditional processing of Dendrobium officinale (DO) is performed in five necessary processing steps: processing fresh strips, drying at 85 °C, curling, molding, and drying at 35 °C (Fengdou). The antioxidant activity of DO is increased after it is processed into Fengdou. To comprehensively analyze the changes in the functional components, a plant-wide target metabolomics approach was employed. In total, 739 differential chemical components were identified in five processing treatments, mainly highlighting differences in the levels of phenolic acids, flavonoids, lipids, and amino acids and their derivatives, and the glycosylation of aglycone resulted in the upregulation of flavonoid glycoside levels. Temperature is a key factor in DO processing during production. In addition, the enrichment of specific differential chemical components was found mainly in five different metabolic pathways: glucosinolate biosynthesis, linoleic acid metabolism, flavonoid biosynthesis, phenylpropanoid biosynthesis, and ubiquinone and other terpene quinone biosynthesis. A correlation analysis clarified that total phenols and flavonoids show a significant positive correlation with antioxidant capacity. This study provides new insights into the influence of the processing processes on DO quality, which may provide guidance for the high-quality production of DO.

Effect of processing methods and storage on the bioactive compounds of black rice (Oryza sativa L.): a review

Compared to brown and white rice, black rice contains more nutrients and numerous unique bioactive substances, such as essential amino acids, dietary fiber, γ-oryzanols, γ-aminobutyric acid, phenolic compounds, and anthocyanins, which makes it highly valuable for development and use. Whole-grain black rice typically requires a certain amount of processing prior to consumption, with the primary goal of enhancing the taste and texture of whole grains and their products. However, various new processing technologies have been effectively applied to the processing of black rice and the enhancement of its qualitative characteristics, but they also have both positive and negative effects on its nutritional quality. Therefore, evaluation of changes in concentrations of the bioactive substances as natural antioxidants due to processing and storage conditions is critical for establishing dietary guidelines for rice. This review highlights the primary bioactive components of black rice and provides a discussion of the impact of processing methods and storage on the bioactive components of black rice. Furthermore, we summarized the issues that currently exist in the processing and storage of black rice.

Microstructural, physicochemical properties and starch digestibility of brown rice flour treated with extrusion and heat moisture

Effects of heat moisture treatment (HMT), extrusion treatment (ET), and the combination treatment (HMT-ET) on microstructural, physicochemical properties, and starch digestibility of brown rice flour (BRF) were investigated. With a rise in resistant starch (RS), melting temperature, and a decrease in swelling capacity (SC), peak viscosity, and apparent amylose content (AAC), the HMT-ET BRF showed a significant lower expected glycemic index (eGI) than HMT and ET. XRD and FTIR results showed ET, HMT-ET caused the transition of starch crystals from amorphous to crystalline region, suggesting the formation of the starch-lipid complex. The analysis of DSC and RVA proved HMT-ET flours induced starch gelatinization and inhibited the starch retrogradation of BRF compared with the other three flours. Correlation analysis suggested that the combined effect of HMT and ET was response for the changes in physicochemical properties and reduction of in vitro starch digestibility. Overall, the BRF after HMT-ET with improved physicochemical properties and starch digestibility could be better utilized as a good substitute for carbohydrate sources.

Extrusion assisted interaction of rice starch with rice protein and fibre: Effect on physicochemical, thermal and in-vitro digestibility characteristics

Rice starch has high digestibility due to its large carbohydrate content. Macromolecular enrichment of starch has the tendency to retard rate of starch hydrolysis. Hence, the current investigation was aimed to check the combined effect of extrusion assisted addition of rice protein (0, 10, 15 and 20 %) and fibre (0, 4, 8 and 12 %) to rice starch on physico-chemical and in-vitro digestibility characteristics of starch extrudates. It was observed from the study that 'a' and 'b' values, pasting temperature and resistant starch of starch blends and extrudates increased with the addition of protein and fibre. However, lightness value, swelling index, pasting properties and relative crystallinity of blends and extrudates decreased with the addition of protein and fibre. Maximum increase in thermal transition temperatures was observed for ESP₃F₃ extrudates due to absorption capacity of protein molecules which led to late onset of gelatinization. Therefore, enrichment of protein and fibre to rice starch during extrusion can be considered as a novel approach to reduce rate of rice starch digestion for catering nutritional requirements of diabetic population.

Efficient Retention and Complexation of Exogenous Ferulic Acid in Starch: Could Controllable Bioextrusion Be the Answer?

The starch-phenolics complexes are widely fabricated as functional foods but with low phenolics retention limited by traditional liquid reaction and washing systems. In this study, ferulic acid (FA, 5%) was exogenously used in the crystalline form, and it reacted with starch in a high-solid extrusion environment, which was simultaneously controlled by thermostable α-amylase (0-252 U/g). Moderate enzymolysis (21 or 63 U/g) decreased the degree of the starch double helix and significantly increased the FA retention rate (>80%) with good melting and distribution. Although there were no significantly strong chemical bonds (with only 0.17-2.39% FA bound to starch hydrolysate), the noncovalent interactions, mainly hydrogen bonds, van der Waals forces, and electrostatic interactions, were determined by ¹H NMR and molecular dynamics simulation analyses. The phased release of total FA (>50% in the stomach and ∼100% in the intestines) from bioextrudate under in vitro digestion conditions was promoted, which gives a perspective for handing large loads of FA and other phenolics based on starch carrier.

Influence of processing on bioactive compounds, Type-II diabetes related enzyme regulation potential and antiurolithiatic potential of underutilized legume Macrotyloma uniflorum

The hydro-alcoholic extract of raw and processed Macrotyloma uniflorum seeds, an underutilized food legume was analysed for its bioactive compounds, Type-II diabetes enzyme regulation and antiurolithiatic potential. The study aimed to establish and promote the introduction of these new grains and enlarge the market of novel functional foods. The seed extract had phenolic content of 35.6 and 30.4 mg GAE/g dm, for PAIYUR-2 and GPM-6 respectively. Chlorogenic, coumaric, vanillic and ellagic were the major and, sinapic and syringic were limiting phenolic acids. The raw seeds extract exhibited ferric ion reducing potential (1125 and 1236 mmol Fe II/mg extract dm), free radical inhibition (EC₅₀, 3.58 and 3.78 g dm/g DPPH), hydroxyl ion inhibition (46.71 and 45.44%) and superoxide ion inhibition (36.93 and 33.37%) for PAIYUR-2 and GPM-6 respectively. Further, considerable α-amylase (49.34 & 45.89%) and α-glucosidase (62.72 & 60.33%) inhibition potentials were observed along with antiurolithiatic activity of 48.12 and 46.31% in PAIYUR-2 and GPM-6 respectively. Although, processing had significant (p ≤ 0.05) impact on grain quality but still the significant (p ≤ 0.05) functional properties were retained. This proves the grain utility as a functional food in maintaining human health.

Arabinoxylans Release from Brewers’ Spent Grain Using Extrusion and Solid-State Fermentation with Fusarium oxysporum and the Antioxidant Capacity of the Extracts

Brewers’ spent grain (BSG) is the most abundant byproduct generated from the beer-brewing process. BSG is a material rich in hemicellulose, composed of arabinoxylans (AX). However, the high crosslinking of this material causes low availability of AX, for which it is necessary to apply different treatments. The objective of this research is to increase the release of arabinoxylans through solid-state fermentation with Fusarium oxysporum f. sp. lycopersici using extruded brewery spent grain. First, the BSG is subjected to two types of physical treatments: extrusion at 20% moisture, 200 rpm and 50 °C (BSGe), and blade milling (BSGm). The chemical composition is determined for each sample (BSG, BSGe and BSGm). Subsequently, the solid-state fermentation process (SSF) is carried out on each sample. The fermentation kinetics at 30 °C are monitored for 7 days. Once the SSF concludes, AX are extracted, and the purity of AX is determined by the phloroglucinol colorimetric assay. Finally, the total phenolic compounds, phenolic acids and antioxidant capacity by DPPH are quantified. No significant differences (p ≥ 0.05) in the protein, lipid, ash or total dietary fiber contents are found among the samples. No significant difference (p ≥ 0.05) in the content of soluble fiber is found, although BSGe and BSGm have higher values than BSG. On the other hand, the yields of soluble AX exhibit significant differences (p ≤ 0.05) among nonfermented samples (BSG, 0.03%; BSGm, 0.53%; BSGe, 0.70%) and with SSF (BSG, 2.95%; BSGm, 6.24%; and BSGe, 9.58%). In addition, the contents of free phenolic compounds and free phenolic acids and the percent inhibition of free extracts by 2,2-diphenyl-1-picrylhydrazyl (DPPH) differ significantly (p ≤ 0.05) between samples subjected to SSF and nonfermented samples. Therefore, extrusion and SSF treatment increase AX release from BSG as well as the antioxidant capacity of the extracts.

Enrichment in Different Health Components of Barley Flour Using Twin-Screw Extrusion Technology to Support Nutritionally Balanced Diets

Due to its good dietary role, barley has attracted a growing amount of interest for the manufacture of functional foods in recent years. In barley, a number of bioactive components, including as phenolic compounds, have been discovered, and barley extrudates could be used to formulate various processed foods, including ready-to-eat cereals, baby, and pet foods and support nutritionally balanced diets. This study was conducted to investigate the effect of extrusion processing on resistant starch (RS), glycemic index (GI), and antioxidant compounds of barley flour. The L^* and ΔE values of barley flours decreased significantly (p < 0.05) after extrusion is done at 150 and 180°C. The a^* and b^* values, however, increased after extrusion. Extrusion increased antioxidant activity (AOA), metal chelating activity (MCA), and ABTS⁺ scavenging activity, whereas total phenolic content (TPC) and total flavonoids content (TFC) decreased. Barley extrudates at 150 and 180°C showed decreased TPC by 16.4–34.2% and 23.4–38.1%. Moreover, improved RS and reduced GI values were recorded for barley extrudates as compared to barley non-extrudates. Therefore, extrusion of barley could be an alternative to produce pregelatinized barley flour with improved RS low GI values and improved antioxidant potential.

Anthocyanins and Functional Compounds Change in a Third-Generation Snacks Prepared Using Extruded Blue Maize, Black Bean, and Chard: An Optimization

The effect of extrusion cooking on bioactive compounds in third-generation snacks (TGSE) and microwave-expanded snacks (MWSE) prepared using black bean, blue maize, and chard (FBCS) was evaluated. FBCS was extruded at different moisture contents (MC; 22.2–35.7%), extrusion temperatures (ET; 102–142 °C), and screw speeds (SP; 96–171 rpm). Total anthocyanin content (TAC), contents of individual anthocyanins, viz., cyanidin-3-glucoside, malvidin-3-glucoside, pelargonidin-3-glucoside, pelargonidin-3-5-diglucoside, and delphinidin-3-glucoside chloride, total phenolic content (TPC), antioxidant activity (AA), and color parameters were determined. TAC and individual anthocyanin levels increased with the reduction in ET. ET and MC affected the chemical and color properties; increase in ET caused a significant reduction in TPC and AA. Microwave expansion reduced anthocyanin content and AA, and increased TPC. Extrusion under optimal conditions (29% MC, 111 rpm, and 120 °C) generated products with a high retention of functional compounds, with high TAC (41.81%) and TPC (28.23%). Experimental validation of optimized process parameters yielded an average error of 13.73% from the predicted contents of individual anthocyanins. Results suggest that the TGSE of FBCS obtained by combining extrusion and microwave expansion achieved significant retention of bioactive compounds having potential physiological benefits for humans.

Release of characteristic phenolics of quinoa based on extrusion technique

Quinoa is rich in phenolics which are benefit for human health for their outstanding antioxidant capacity, anti-inflammatory property and special biological functions. However, most of phenolics existed as bound form that with low bioavailability in quinoa. In this study, extrusion technique was applied for the release of bound phenolics in red quinoa (RQ), and effects of extruded temperature (120 °C, 140 °C, 160 °C and 180 °C) on the release of characteristic phenolics of RQ was investigated as well. Phenolics both presented as free and bound forms were identified in RQ and extruded quinoa samples, and result showed rutin, ferulic acid and vanillic acid were most common. The content of bound phenolics in RQ was 155.52 mg/kg, however, in extruded red quinoa (ERQ) was 77.25 mg/kg (ERQ-140 °C)-84.08 mg/kg (ERQ-120 °C). In corresponding, free phenolics in RQ was 22.15 mg/kg, while in ERQ was 41.04 mg/kg (ERQ-140 °C)-47.25 mg/kg (ERQ-160 °C). In conclusion, extrusion was excellent for the release of bound phenolics in quinoas and the best extruded temperature was 160 °C. Extrusion technique was potential in the processing of quinoa.

Effect of carboxymethylcellulose and locust bean gums on some of physicochemical, mechanical, and textural properties of extruded rice

Extrusion is a composite process consisting of many different unit operations such as mixing, cooking, pasting, and molding. In this process, the raw material is forced through a tiny opening to be transformed into a product with a desired and unique shape, texture, color, and taste. In combination with different amounts and types of additives, this technique can result in functional food products for a broad range of people suffering from micronutrient deficiency. The hydrocolloid compounds are now employed to improve the texture and performance properties of many food products. Therefore, this study scrutinized the effects of carboxymethylcellulose and locust bean gums at different levels (0.5, 0.75, and 1%) alone or in combination with each other on chemical, physical, mechanical, and textural properties of extruded rice in comparison with the qualitative properties of the control rice. A completely random design was used along with three replications to analyze the test results. Then the means were compared through Duncan's multiple range test at (α = 5%). According to the results, addition of gums increased moisture, ash, total color difference, water absorption capacity, solubility, failure force, rupture energy, elasticity module, and toughness when reduced lateral expansion was compared to the control. Moreover, the addition of gums after the cooking process increased cooking loss, texture hardness, chewability, and elasticity of the specimens in comparison with the control. According to the results of pre- and post-cooking tests, the specimens containing locust (0.75%) and carboxymethylcellulose (0.75%) gums were the best treatments.

Solutions for whole grain food development

Owing to the health benefits associated with whole grains, there has been a sustained global effort to increase their consumption, with many countries developing guidelines for recommended amounts of whole grain intake. In China, the consumption of whole grains is low. This is due, in part, to technical obstacles in the development of whole grain foods. This review focuses on possible solutions in the whole value chain and the application of new food technologies to develop whole grain foods that taste better, have more appealing texture, are safe to consume, and better retain bioactive compounds.

Influence of processing methodology on phenolic acid content, fatty acid profile and oxidative stability of Macrotyloma uniflorum

Study was conducted to determine the influence of different cooking methods namely pressure, flaking, infra-red, microwave and extrusion processing on rate of oxidative stability, fatty acid profile and functional properties of horse gram. The rate of auto-oxidation was significantly (p < 0.05) affected during storage and found maximum at 0.00 aw and minimum at 0.33 aw for both varieties namely GPM-6 and PAIYUR-2. The extrusion processed grains were more susceptible to auto-oxidation. The iron content of grain increased significantly (p < 0.05) during extrusion (1.22 ± 0.50 to 1.65 ± 0.15 mg 100 g-1 for PAIYUR-2 and 1.19 ± 0.45 to 1.59 ± 0.12 mg 100 g-1 for GPM-6). Whereas, tocopherol content decreased during extrusion (8.05 ± 0.15 to 2.28 ± 0.23 mg 100 g-1 for PAIYUR-2 and 6.48 ± 0.46 to 1.68 ± 0.15 mg 100 g-1 for GPM-6). Ellagic (12.36 ± 0.35 and 10.71 ± 0.29 mg 100 g-1), vanillic (15.20 ± 0.23 and 12.48 ± 0.18 mg 100 g-1), and coumaric acid (14.68 ± 0.71 and 8.97 ± 0.66 mg 100 g-1) were the major phenolic acids whereas, linoleic (35.53 ± 0.30 and 35.46 ± 0.19%), palmitic (26.08 ± 0.26 and 25.97 ± 0.33%), and linolenic acid (13.44 ± 0.18 and 10.13 ± 0.21%) were the major fatty acids present in raw grain for PAIYUR-2 and GPM-6 respectively. Phenolic and fatty acids were significantly (p < 0.05) affected during processing. The oxidative stability of microwave processed grains was maximum whereas, extrusion processed grains showed minimum oxidative stability during storage. Study explicitly describes that native grains and the grains which did not undergo destruction of naturally present cellular structure, were less prone to oxidation. The oxidation rate of grains was found dependent on composition, processing and storage environment of grains. Hence, all these factors need to be considered to ensure the stability of processed food during storage.

Steam flash explosion pretreatment enhances soybean seed coat phenolic profiles and antioxidant activity

The resource utilization of soybean seed coats is currently poor. In this study, steam flash explosion (SFE) pretreatment was performed to extract valuable phytochemicals from soybean seed coats. The total content of phytochemicals and the antioxidant activity of extracts from SFE-treated soybean seed coat were systematically evaluated. On the basis of the application value of antioxidant activity, we optimized the process parameters of SFE-pretreated soybean seed coat to maximize the antioxidant activity. Additionally, the subsequently obtained ethyl acetate fraction with the highest antioxidant activity was analysed using HPLC-DAD-Q-Orbitrap HRMS/MS analysis. The results indicated that SFE could enhance the release of both aglycone and acetylglucoside forms of isoflavones from the cellular structure and enhance the antioxidant activity of soybean seed coats. This study provides evidence that SFE is a novel thermal processing technology with high efficiency and low energy consumption that improves the phytochemical composition and bioactivity of soybean seed coats.

Effects of different industrial processes on the phenolic composition of white and brown teff (Eragrostis tef (Zucc.) Trotter)

Teff is currently being incorporated into a range of foodstuffs, especially gluten-free flakes and extruded products. The main objective of this work was to assess the effects of different treatments (industrial milling, formation of flakes and extrusion) on the phenolic composition of two types of teff grains differing in their colour (white and brown). Fifty-nine phenolic compounds were detected by HPLC-DAD-MSⁿ. C-glycosyl flavones accounted for more than 90% of the total phenolic contents in both teff types. White teff mostly contained apigenin-derived flavones (86-92%), whereas luteolin derivatives prevailed in brown teff (91-94%). The industrial processes, mainly flaking and extrusion, caused marked changes in the phenolic composition, some of which were dependent on the teff type. In both teff types, processing changed the phenolic profiles similarly by increasing C-monoglycosyl flavones and decreasing acylated derivatives. However, the total content was increased in flakes and extruded products made only from brown teff grains.

Effect of Extrusion Processing Conditions on the Phenolic Compound Content and Antioxidant Capacity of Sorghum (Sorghum bicolor (L.) Moench) Bran

Sorghum is a cereal with little use in human diet; however, this grain can provide several nutrients and, additionally, has a high content of phenolic compounds concentrated in bran, which could be beneficial to human health due to its high antioxidant capacity. However, these bioactive compounds are bound within the cell wall matrix; it is necessary to release these compounds to take advantage of their antioxidant properties. The extrusion process increases the accessibility of bound phenolic compounds, breaking their bonds from the bran matrix. The aim of this study was to determine the optimal extrusion conditions for maximizing the phenolic compound content and antioxidant capacity of sorghum bran extrudate. The extrusion process factors evaluated were feed moisture (FM) from 25 to 35% and the fourth extrusion zone temperature (T) in the range of 140-180 °C. Analysis of variance and response surface analysis were used in the evaluation. The prediction coefficient, (FM)², (T)² and their interaction (FM)(T) significantly affected the free total phenolic compounds. The antioxidant capacity of the free total phenolic compounds was significantly affected by (FM)² and (T)². The optimal extrusion conditions were FM = 30% and T = 160 °C, which provided free total phenolic compounds with a value of 7428.95 μg GAE/g (predicted value: 7810.90 μg GAE/g) and antioxidant capacity with a value of 14.12 μmol TE/g (predicted value: 14.85 μmol TE/g). Results confirmed that extrusion process optimization was useful to increase the content of phenolic compounds and improved the antioxidant capacity of sorghum bran.

Extrusion and nixtamalization conditions influence the magnitude of change in the nutrients and bioactive components of cereals and legumes

Cereal and legume diets make up the bulk of caloric sources for a majority of households in the developing world. They contain macro- and micronutrients as well as phytochemicals embedded as one matrix. Some phytochemicals are antinutritional factors which can bind nutrients thereby hindering their bioavailability. While there are other methods that can be used to enhance nutrient utilization from such foods, we summarize how food processing methods such as extrusion and nixtamalization are employed to break the food matrix and release these nutrients. Both extrusion and nixtamalization can break down complex carbohydrates into simpler, more soluble forms while at the same time inactivating or denaturing protein inhibitors and other antinutritional factors. Such disruptions of complexes within the food matrix are essential for harnessing optimum nutritional and health benefit from these foods. We present mechanistic approaches explaining how these processes enhance nutrient and mineral bioavailability and phytochemical bioactivity while minimizing the undesirable effects of antinutritional factors that coexist in the complex food matrix.

Whole Grain Brown Rice Extrudate Ameliorates the Symptoms of Diabetes by Activating the IRS1/PI3K/AKT Insulin Pathway in db/db Mice

The therapeutic benefits of whole grains on diabetes mellitus have been continuously confirmed by in-depth research. To date, limited studies have investigated the effect of extruded products of whole grains on the insulin signaling pathway in vivo. This study investigated the effects of oral consumption of whole grain extrudate, including 97% brown rice and 3% defatted rice bran (w/w, BRD), on glucose metabolism and the hepatic insulin signaling pathway in C57BL/KsJ-db/db mice. BRD treatment induced a remarkable reduction in blood glucose. Moreover, glucose intolerance and insulin resistance were ameliorated in the BRD-treated group compared with those in the db/db control group. BRD also increased the hepatic glycogen content by reducing the expression and increasing the phosphorylation of glycogen synthase kinase 3β (GSK3β). The activities of glucose-6-phosphatase and phosphoenolpyruvate carboxylase and their respective mRNA expression levels in the liver were simultaneously decreased in the BRD-treated group. BRD also significantly upregulated the expression of phosphatidylinositol 3-kinase (PI3K) and increased the phosphorylation of insulin receptor substrate 1 (IRS1) and protein kinase B (AKT). These results indicate that BRD exhibits antidiabetic potential by activating the IRS1/PI3K/AKT signaling pathway, further regulating the expression of the FOXO1 gene and p-GSK3β protein, thus inhibiting hepatic gluconeogenesis, increasing hepatic glycogen storage, and improving insulin resistance. Therefore, BRD could be used as a functional ingredient to alleviate the symptoms of hyperglycemia.

Black rice (Oryza sativa L.): A review of its historical aspects, chemical composition, nutritional and functional properties, and applications and processing technologies

Black rice is a variety of pigmented rice. It contains numerous nutritional and bioactive components, including essential amino acids, functional lipids, dietary fibre, vitamins, minerals, anthocyanins, phenolic compounds, γ-oryzanols, tocopherols, tocotrienols, phytosterols and phytic acid. There have been several studies of black rice due to its alleged beneficial health effects when consumed regularly. This review focuses on the historical aspects, chemical composition, and nutritional and functional properties of black rice. Furthermore, a discussion of the development of new foods and beverages with applications and processing technologies designed to improve their quality attributes. The nutritional value of black rice means that it has the potential to be used in the production of healthy foods and beverages, such as functional products and gluten-free cereals, thereby providing extra health benefits to consumers.

Influence of parboiling of red paddy varieties by simple hot soaking on physical, nutrient, phytochemical, antioxidant properties of their dehusked rice and their mineral, starch, and antioxidant's bioaccessibility studies

The objective of this study was to know about the effect of simple parboiling on physical properties, proximate composition, phenolic compounds, and antioxidant activity.  These were  studied in raw and parboiled paddy varieties as well as bioaccessibility of specific nutrients (minerals, starch, and antioxidants). The pigmented rice paddy varieties such as Jyothi, Meter & Athikaraya were parboiled by hot soaking treatment after soaking for 2, 2½, and 3 hr. Athikaraya rice showed high protein, low ash in raw and parboiled than other varieties. Amylose equivalents of all three varieties exhibited in the range of 24%-27% (d.b). Whereas, the soluble amylose content showed 12.7, 8.7, and 7.7% (d.b) in Athikaraya, Meter and Jyothi rice varieties, respectively. Jyothi rice showed less cooking time and more cooking volume. Athikaraya showed high phenolic content and antioxidant properties compared to other two varieties. The dialysability of minerals, starch, and antioxidants were increased due to simple hot soaking parboiling. PRACTICAL APPLICATIONS: The present study has the significance in assessing the variation among different pigmented rice varieties after parboiling by simple hot soaking with various soaking periods. The industrial advantage of this method is, there is no usage of boiler for cooking the paddy by steam, which was economically better. The information gained by this study might be beneficial for consumers and suppliers regarding the quality of the selected pigmented rice varieties with respect to nutrient composition, antioxidant activities, and bioaccessibility of minerals, starch, and antioxidants. Ultimately, the present study can lead to better appreciation of pigmented rice and assist food processors in selecting rice variety with unique characteristics for specialty food preparations.

Effects of extrusion conditions on chemical properties of extruded white ginseng root hair

BACKGROUND

This study was to investigate the significant effects of extrusion process variables on chemical properties of extruded white ginseng root hair. The extrusion conditions were set as follows: barrel temperature (110 and 140 °C), moisture content (20 and 30%) and screw speed (200 and 300 rpm). The powder of white ginseng root hair was extruded as L₈ (2⁷ ) orthogonal experimental design.

RESULTS

The crude saponin and acidic polysaccharide contents of extrudate were significantly higher than those of raw material after extrusion. In addition, antioxidant properties were also increased, while reducing sugar content was markedly lower than that of raw material. Moisture content was the most significant factor affecting the reducing sugar, acidic polysaccharide and total phenolic contents, and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. Barrel temperature significantly affected reducing power, and screw speed significantly influenced crude saponin content.

CONCLUSIONS

The extrusion process aided in improving the amount of beneficial compounds from white ginseng root hair. © 2018 Society of Chemical Industry.

Use of blackcurrant and chokeberry press residue in snack products

Fruit and vegetable processing by-products, undervalued until recently, are rich sources of nutrients. This study investigated properties of extruded corn puffs with addition (5–20%) of blackcurrant or chokeberry pressings. We assessed expansion rate, water absorption index (WAI) and water solubility index (WSI) of the produced extru-dates, the concentration of polyphenols, and antioxidant activity measured by FRAP method and ABTS method. The puffs with addition of chokeberry pressings had higher WSI values, higher phenolic acids, flavonols, and anthocyanins content, and higher antioxidant activity than puffcorn with addition of blackcurrant pressings. The corn puffs with addition of fruit pressings contained much higher concentrations of phenolic compounds and were characterized by much higher antioxidant activity than pure puffcorn. This confirms the usefulness of addition of such fruit processing by-products in order to manufacture functional food.