Influence of γ-irradiation on physicochemical, functional, proximate, and antioxidant characteristics of pigmented rice flours.

In recent years, food irradiation using γ-rays is one of the most valuable practices for insect disinfestation in rice grains for extended shelf life. In this study, flours from four pigmented rice cultivars were exposed to γ-irradiation using 60Co at different doses (0, 5, 10, and 15 kGy). The impact of γ-irradiation on the physico-chemical, functional, and morphological characteristics of pigmented rice flours were analyzed. Results revealed that reduction in amylose content, pH, bulk density, tapped density, and syneresis, while solubility, water absorption capacity, and swelling power values increased significantly (p < 0.05). Pasting characteristics of pigmented rice flours also reduced after exposure to γ-irradiation. Morphological features of pigmented rice flour granules revealed no evidence of physical destruction after irradiation except for black kavuni flour. The structural analysis by FTIR confirms no effect of γ-irradiation on pigmented rice flours. Overall, the study revealed that irradiated pigmented rice flours with enhanced functional properties of less than 10 kGy can be effectively used in the development of value-added rice-based food products considering all the beneficial and safety aspects. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05709-z.

Evaluation of Metabolite Profiles of Ginseng Berry Pomace Obtained after Different Pressure Treatments and Their Correlation with the Antioxidant Activity.

Ginseng berry pomace (GBP) is a byproduct of ginseng berry processing and is rich in numerous bioactive components, including ginsenosides and their derivatives. The application of GBP as a beneficial biomaterial is currently limited. In this study, we aimed to evaluate their potential as a promising source of bioactive compounds using metabolite profiling. The GBP obtained after different ultra-high-pressure (UHP) treatments was analyzed by GC-TOF-MS and UHPLC-LTQ-Orbitrap-MS/MS. In multivariate analyses, we observed a clear demarcation between the control and UHP-treated groups. The results demonstrated that the relative abundance of primary metabolites and a few ginsenosides was higher in the control, whereas UHP treatment contained higher levels of fatty acids and sugars. Furthermore, GBPs were fractionated using different solvents, followed by UHPLC-LTQ-Orbitrap-MS/MS analyses. The heatmap revealed that phenolics (e.g., quercetin, kaempferol) and fewer polar ginsenosides (e.g., F4, Rh2) were abundant in the ethyl acetate fraction, whereas the levels of lignans (e.g., 7-hydroxysecoisolariciresinol, syringaresinol) and fatty acids (e.g., trihydroxy-octadecenoic acid, oxo-dihydroxy-octadecenoic acid) were high in chloroform. Correlation analysis showed that phenolics, less polar ginsenosides, and fatty acids were positively correlated with the antioxidant activity of GBP. Our study highlights GBP as a functional ingredient for the development of high-quality ginseng berry products.

Impact of γ-irradiation on physicochemical characteristics, lipoxygenase activity and antioxidant properties of finger millet.

In the present study, the finger millet grains were subjected to γ-irradiation at four different dosage levels: 2, 5, 10, and 15 kGy. Effect of γ-irradiation on the proximate composition, pasting properties, lipoxygenase activity, and antioxidant properties of finger millet flour was evaluated. Moisture, protein, fat, ash, and carbohydrate content of native flour was 12.96, 6.85, 2.73, 1.57, and 73.69 g/100 g, respectively. According to the results of proximate analysis, γ-irradiation significantly (p < 0.05) reduced the moisture contents and increased protein contents; however, the fat content of the irradiated flour was equal to or lower than that of the native flour. Pasting properties of the finger millet flour was reduced with the γ-irradiation. Compared with the native flour, lipoxygenase activity and malondialdehyde content decreased and radical scavenging activity, catalase, and superoxide dismutase activities increased in the irradiated flour with increasing γ-irradiation doses. Finally, the present study suggested that the γ-irradiation process improved the antioxidant enzymes and physicochemical characteristics; which could be helpful in formulating tailored made food products.

Physicochemical, morphological and functional properties of protein isolates obtained from four fish species.

In this study, we investigated the physicochemical, morphological and functional characteristics of fish protein isolates (FPIs) prepared from four fish species through alkali solubilization and isoelectric precipitation. Significant differences were observed in the protein content, physicochemical, morphological and functional characteristics among FPIs. Morphology and particle size analysis revealed a significant difference in the shape and size of FPIs. Lipid oxidation of FPIs varied between 0.206 and 0.305 mg MDA/kg. Furthermore, all FPIs exhibited two broad diffraction peaks at ~ 8.6° and 19.3°, revealing their amorphous nature. A significant difference was observed in the thermal properties of selected samples, including T0, TP, TC, and ΔH values. T0, TP, TC, and ΔH of the endothermic transition varied in the range of 40.9-43.0 °C, 64.1-66.2 °C, 99.1-100.6 °C, and 237.1-267.2 J/g, respectively. All FPIs exhibited high water/oil absorption capacity, emulsifying capacity, foam stability and foaming capacity, signifying proteins potential to act as functional ingredients in the food industry.

Functional and physicochemical characteristics of cookies prepared from Amorphophallus paeoniifolius flour.

This study was undertaken to prepare novelly formulated cookies from elephant foot yam flour (EFYF) with refined wheat flour (RWF) and evaluate their proximate composition, quality characteristics, texture, pasting and organoleptic properties. The formulated cookies prepared from EFYF, substituting RWF up to 70% had sensory properties similar to that of refined flour cookies (control). EFYF and RWF blend revealed reduced water and oil absorption capacity with increased peak and final viscosities when compared with RWF. Reduced lightness, increased redness and hardness were observed for formulated cookies with increase in storage time. Irrespective of the decreasing trend in their texture, overall acceptance of the EFYF cookies by the consumers was increased. Sensory scores revealed the preference of consumers towards formulated cookies. Overall analysis disclosed that the cookies prepared from A. paeoniifolius flour proved acceptable not only in quality characteristics but also fulfil the demand of functional foods in preparation of cookies.

Pasting, textural and thermal properties of resistant starch prepared from potato (Solanum tuberosum) starch using pullulanase enzyme.

Pullulanase enzyme (40 U/g, 10 h) was used for enzymatic hydrolysis of potato starch which was autoclaved (121 °C/30 min), stored under refrigeration (4 °C/24 h) and lyophilized. Comparison of morphological, pasting, textural and thermal properties among native hydrolysed starch (V2) and gelatinized hydrolysed starch (V3) prepared using pullulanase enzyme on potato starch (V1) were studied. The round, elliptical, irregular and oval shape with smooth surface of V1 was replaced with amorphous mass of cohesive structure leading to loss of granular appearance in V2 and V3. The percentage of amylose and resistant starch content of V2 (27.16 %) and (24.16 %); V3 (51.44 %) and (29.35 %) was higher when compared to V1 (22.17 %) and (3.62 %). The swelling power of V1 observed at 60 °C (0.85 %) and 95 °C (8.64 %) were significantly different from V2 at 60 °C (4.97 %) and 95 °C (7.66 %) and that of V3 at 60 °C (5.82 %) and 95 °C (7.5 %). Significance difference in water solubility (7.62 %) and absorption capacity (6.11 %) was noted in V3 when compared with V1 and V2 owing to amylose/amylopectin content. Increase in water solubility and absorption capacity along with decrease in swelling power of V2 and V3 was noted due to hydrolytic and thermal process. RS obtained from hydrolysis showed a reduction in viscosity, indicating the rupture of starch molecules. The viscosity was found to be inversely proportional to the RS content in the sample. The thermal properties of RS increased due to the retrogradation and recrystallization (P < 0.05).

Solid-State Fermentation With Aspergillus cristatus Enhances the Protopanaxadiol- and Protopanaxatriol-Associated Skin Anti-aging Activity of Panax notoginseng.

A metabolomics approach was used to profile metabolites of Panax notoginseng fermented with Aspergillus cristatus in two ways, liquid-state fermentation (LF-P) and solid-state fermentation (SSF-P) and examine metabolite markers representing antioxidant activity and skin anti-aging. Protopanaxadiol (PPD) and protopanaxatriol (PPT) contents were higher in SSF-P than in LF-P and showed a multiplicative increase over the fermentation period of four days. PPD and PPT levels also correlated with antioxidant and anti-aging effects in skin, based on the mRNA expression of dermal extracellular matrix components. In the bioactivity validation assays, PPD and PPT significantly improved the expression of type-I collagen, fibrillin-1, and elastin in human dermal fibroblasts from both young and old subjects; these were comparable with the effects of the SSF-P extracts. Overall, our results suggest that changes in the metabolites of P. notoginseng fermented with A. cristatus enhance the quality and availability of bioactive compounds associated with skin anti-aging.

Comprehensive Metabolite Profiling and Microbial Communities of Doenjang (Fermented Soy Paste) and Ganjang (Fermented Soy Sauce): A Comparative Study.

Doenjang and ganjang are secondary fermented soybean products from meju (primary fermented product) following a complex fermentation process that separates the products into solid (doenjang) and liquid (ganjang) states. We performed a comparative study on gas chromatography mass spectrometry-(GC-MS) and liquid chromatography mass spectrometry-(LC-MS) based metabolite profiling with fungal and bacterial microbial community analysis of doenjang and ganjang during fermentation. Metabolite profiling and microbial community data showed distinct patterns, depending on the fermentation process. The relative levels of metabolic patterns were similar and most of the microorganisms produced halophilic or halotolerant microbes during the fermentation period in doenjang and ganjang. In the doenjang end products, isoflavones, soyasaponins, and amino acids were largely distributed and Debaryomyces and Staphylococcus were dominant, whereas the biogenic amine and phenylpropanoid contents were highly distributed in the ganjang end products, with higher levels of Meyerozyma and Tetragenococcus. Our results demonstrate that the quality of doenjang and ganjang is predominantly influenced by the microbiome and by metabolite changes during fermentation. Moreover, the present study provides a platform for comparing samples in different states.

Morphological, physico-chemical and functional properties of underutilized starches in China.

In this study, starches were isolated from different non-conventional sources (acorn, black wheat, buckwheat, coix seed, jiaoyu, kuzhu, longya lily, and naked oat) cultivated in China, and their morphological, physico-chemical, and functional properties were analyzed. Among isolated starches, significant differences (p < 0.05) were observed in morphology, pasting, crystallinity, physico-chemical, and functional properties. After a comparison with commercial corn starch, all these isolated starches presented promising and unique characteristics. The XRD profile of isolated starches presented A-type (naked oat, buckwheat, coix seed, and black wheat), B-type (longya lily, acorn and jiaoyu) and C-type (kuzhu) polymorphic structures. SEM analysis revealed that the starches isolated from different sources showed distinct shapes exclusively globular, elliptic, and polygonal shapes. The high viscosity of jiaoyu and kuzhu starch pastes can be utilized to have an advantage in instant soups and sauces. Hence, the present study will improve the scientific basis on starches from different non-conventional sources, facilitate their utilization in a variety of applications.

Metabolite Profiling and Microbial Community of Traditional Meju Show Primary and Secondary Metabolite Differences Correlated with Antioxidant Activities.

Meju, a type of fermented soybean paste, is used as a starter in the preparation of various Korean traditional soybean-based foods. In this study, we performed Illumina-MiSeq paired-end sequencing for microbial communities and mass spectrometry analysis for metabolite profiling to investigate the differences between 11 traditional meju products from different regions across Korea. Even though the bacterial and fungal communities showed remarkable variety, major genera including Bacillus, Enterococcus, Variovorax, Pediococcus, Weissella, and Aspergillus were detected in every sample of meju. The metabolite profile patterns of the 11 samples were clustered into two main groups: group I (M1-5) and group II (M6-11). The metabolite analysis indicated a relatively higher amino acid content in group I, while group II exhibited higher isoflavone, soyasaponin, and lysophospholipid contents. The bioactivity analysis proved that the ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was higher in group II and the FRAP (ferric reducing antioxidant power) activity was higher in group I. The correlation analysis revealed that the ABTS activity was isoflavonoid, lipid, and soyasaponin related, whereas the FRAP activity was amino acid and flavonoid related. These results suggest that the antioxidant activities of meju are critically influenced by the microbiome and metabolite dynamics.

Functional and thermal behaviors of heat-moisture treated elephant foot yam starch.

Elephant foot yam starch (EFYS) granules were subjected to heat-moisture treatment (HMT) at 110 °C for 3 h with different moisture levels ranging from 15% to 35%. The effects of HMT on the morphology, crystalline structure, and pasting properties of the EFYS granules as well as the thermal and functional properties of HMT-modified starch (HMTS) granules were examined. Scanning electron microscopy showed that the EFYS granules were spherical, but the HMTS granules exhibited granular aggregation and fissures and cavities on the granule surfaces. After HMT, significant (p < 0.05) differences were observed in the color, crystallinity, and water activity between the EFYS and HMTS granules. Both the type of granules exhibited C-type crystalline structure. The solubility and pasting temperature was significantly higher (p < 0.05) but swelling power was significantly lower in the HMTS than in the EFYS granules. The HMTS granules exhibited higher gelatinization temperatures and lower gelatinization enthalpy than the EFYS granules. The results showed that HMT significantly changed the physicochemical and functional properties of EFYS; thus, HMT can considerably expand the range of EFYS applications and enable its use in manufacturing products, such as extruded foods, thickeners, and binding agents, which require processing at high temperatures.

Health-promoting effects of konjac glucomannan and its practical applications: A critical review.

Konjac glucomannan (KGM) is a dietary fiber hydrocolloidal polysaccharide isolated from the tubers of Amorphophallus konjac. Over the last few decades, the purified KGM has been offered as a food additive as well as a dietary supplement in many countries. Also, a diet containing konjac flour or KGM is considered as healthier, and these foods are popular in many Asian and European markets. Further, due to the adhesive property of KGM, it can form a defensive covering on the surface of the intestine. Additionally, KGM can reduce the levels of glucose, cholesterol, triglycerides, and blood pressure and can enable weight loss. Its wide-ranging effects prevent many chronic diseases through the regulation of metabolism. In this review, the recent studies on the health benefits such as anti-diabetic, anti-obesity, laxative, prebiotic, and anti-inflammatory activities of KGM were discussed. Also, this review deals with the applications of KGM and its derivatives in bio-technical, pharmaceutical, tissue engineering, fine chemical fields, etc.

Enhanced accumulation of gamma-aminobutyric acid in rice bran using anaerobic incubation with various additives.

An anaerobic incubation for the enzymatic production of gamma-aminobutyric acid (GABA) in rice bran with the addition of glutamate, hydrolyzed wheat protein (HWP), yeast extract (YE) and pyridoxal-5-phosphate (PLP) was investigated. Rice bran was moistened (30% moisture content) with an electrolyzed oxidizing water and anaerobically incubated under nitrogen at 40 °C for 8 h. The incubation activated the glutamate decarboxylase (GAD) in rice bran and increased the GABA content from 10.7 to 171.5 mg/100 g. The addition of glutamate and protein hydrolysates further amplified the GABA content in the treated rice bran: 974.9, 487.4, and 372.8 mg/100 g, with 2.25% glutamate, 6% HWP, and 8% YE, respectively. Furthermore, addition of PLP (1.48 mg/100 g) as a coenzyme for GAD, together with 2.25% glutamate addition, could raise the GABA accumulation in rice bran to 2242 mg/100 g. Other amino acids in rice bran were changed in their composition by the anaerobic treatment.

Hydrocolloidal properties of flaxseed gum/konjac glucomannan compound gel.

The present study was designed to determine the hydrocolloidal properties and synergistic effect of a novel compound gel prepared under specific physical gelling conditions using flaxseed gum (FSG) and konjac glucomannan (KGM); and proposed the possible application of compound gel in the food industry. The hydrocolloidal properties of compound gel was examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), rapid visco analyzer (RVA), turbidimeter, texture analyzer (TPA), differential scanning calorimeter (DSC). Among compound gels significant differences (p < 0.05) were observed in microstructure, infrared spectra, gelatinization temperatures, swelling power, solubility, turbidity, texture and pasting characteristics depending upon their concentrations of FSG and KGM. The microstructures of compound gels became dense with small size of pores and showed a strong interaction and synergistic effect between FSG and KGM; whereas increased the pore size of compound gel by increasing the concentration of KGM. FT-IR spectra demonstrated an obvious interaction between FSG and KGM molecular chains in the compound gels.

Enhanced bioavailability of alpha-lipoic acid by complex formation with octenylsuccinylated high-amylose starch.

An aqueous dispersion of alpha-lipoic acid (ALA) using octenylsuccinic anhydride-modified high-amylose starch (OS) was prepared, and thermal stability and cellular bioavailability of ALA were compared with those prepared using native high-amylose starch (HA) and beta-cyclodextrin (ß-CD). The ALA was homogeneously dispersed via the encapsulation of V-type amylose helices. In comparison with HA and ß-CD, OS exhibited a higher ALA absorption in Caco-2 cells, indicating the OS facilitated the intestinal epithelial transport of ALA. Oral administration of the encapsulated ALA in-vivo resulted in a higher maximum ALA plasma concentration and extended the terminal half-life by 30-40%. The area under the plasma concentration vs. time for the administration of ALA complexed by OS was 50% larger than that by HA, indicating the effectiveness of OS in enhancing the oral bioavailability of ALA. These results indicate that OS is an efficient carrier for ALA in oral delivery and bioavailability.

A systematic comparative study on morphological, crystallinity, pasting, thermal and functional characteristics of starches resources utilized in China.

In this study, starches from diverse botanical sources (arrowroot, cassava, Chinese yam, fern root, kidney beans, lotus seed, taro, and water chestnut) were isolated and examined for morphological, pasting, thermal, and physico-chemical characteristics in order to distinguish their end use potential. Among isolated starches significant differences (p < 0.05) were observed in gelatinization temperatures, morphology, color, pasting, and functional properties. Amylose content of isolated starches varied between 17.12% and 35.62%. X-ray diffraction pattern of isolated starches displayed A-type (arrowroot, cassava, corn, and kidney bean), B-type (potato) and C-type (water chestnut, taro, Chinese yam, fern root, and lotus seed) crystalline pattern. The FT-IR spectra of isolated starches confirmed their carbohydrate nature. Furthermore, the current study affords information for the exploitation of isolated starches from the diverse botanical sources cultivated in China that would be convenient for commercial applications.

Influence of debranching and retrogradation time on behavior changes of Amorphophallus paeoniifolius nanostarch.

In this study, Amorphophallus paeoniifolius (elephant foot yam) starch nanoparticles (SNPs) were produced using a native facile and green procedure integrated with debranching and recrystallization. SNPs were produced through debranching with pullulanase followed by 12- and 24-h retrogradation time. Transmission electron microscopy, dynamic light scattering, infrared spectroscopy, differential scanning colorimetry, and X-ray diffraction were utilized to illustrate the morphology, molecular structure, in vitro digestibility, and behavior changes of SNPs. The results revealed that debranching and the retrogradation time influenced the yield of SNPs. The results showed that the particle size of the nanoparticles ranged between 182.07 and 198.1 nm. Prolonging the retrogradation time from 12 to 24-h led to an increase in gelatinization temperatures and enthalpy of SNPs. In contrast with the traditional method for preparing SNPs, the method developed in the present study has the advantages of increased yield and rapidity, and also useful for developing new materials in biomedical applications.

Complex formation between starch and stearic acid: Effect of enzymatic debranching for starch.

Effect of debranching for a high-amylose starch (∼70% amylose) on its V-complex formation with stearic acid was examined. Gel-permeation chromatograms showed that amylopectin was degraded to smaller molecules as the debranching time increased from 6 to 24 h. Increased formation of debranched starch/stearic acid complexes (recovery yield of stearic acid from 45.17 to 89.31% and starch from 39.92 to 55.43%) was observed with increased debranching time (from 6 to 24 h) and complexation time (from 6 to 24 h). The X-ray diffraction patterns of the debranched starch/stearic acid complexes displayed a mixture of B-type and V-type patterns, with 2θ peaks at 7.6°, 13.1°, 17.2°, 20°, 21.6°, and 23.4°. The melting temperature and enthalpy changes of the debranched starch/stearic acid complexes were gradually enhanced with increasing debranching time. These results suggest that starch can be modified by debranching to produce a significant amount of debranched starch/stearic acid complexes.

Morphology, crystallinity, pasting, thermal and quality characteristics of starches from adzuki bean (Vigna angularis L.) and edible kudzu (Pueraria thomsonii Benth).

Starches were isolated from adzuki bean (Vigna angularis L.) and edible kudzu (Pueraria thomsonii Benth) and investigated for their physico-chemical, morphological, pasting, crystallinity, thermal and FT-IR spectroscopic characteristics. Statistical analysis of physico-chemical and functional characteristics showed significant (p<0.05) difference between isolated starches from adzuki bean and edible kudzu. The XRD pattern of starches from adzuki bean and edible kudzu showed A-type with reflections (2θ) at 15.0°, 17.03°, 17.89°, 23.18°and 15.12°, 17.03°, 17.77°, 23.3°, respectively. The starch granules from adzuki bean were smooth, round, oval to kidney or irregular while those of edible kudzu starch were spherical, hemispherical and polygonal. Edible kudzu starch exhibited high pasting temperature, gelatinization temperatures, enthalpy and less pasting parameters as compared to starch from adzuki bean. Peaks in FT-IR spectra of both starches shown its carbohydrate nature. Starch from adzuki bean showed high swelling power and solubility as compared to edible kudzu, and enhanced the swelling power and solubility of isolated starches with the temperature raised from 50°C and 90°C. Finally, this work offers data for the application of starches isolated from adzuki bean and edible kudzu that would be applicable for both food and non-food industries.

Synthesis and physico-chemical characterization of modified starches from banana (Musa AAB) and its biological activities in diabetic rats.

This study describes a simple method of preparation and physico-chemical properties of modified starches (type-3 resistant starches) from banana (Musa AAB), and the modified starches investigated as functional food with a beneficial effect on type-2 diabetes. RS3 was prepared using a method combined with debranching modification and physical modification; native and modifies starches were characterized by scanning electron microscope (SEM), powder X-ray diffraction (XRD), differential scanning calorimetry (DSC) and rapid visco analyzer (RVA). Use of the enzymatic and physical modification methodology, improved the yield of RS (26.62%) from Musa AAB. A reduced viscosity and swelling power; increased transition temperatures, water absorption capacity and solubility index with B-type crystalline pattern and loss of granular appearance were observed during the debranching modification and physical modification. The modified starches exhibited beneficial health effects in diabetic and HFD rats who consumed it. These results recommend that dietary feeding of RS3 was effective in the regulation of glucose and lipid profile in serum and suppressing the oxidative stress in rats under diabetic and HFD condition. This current study provides new bioactive starches, with potential applications in the food and non-food industries.