Characterization of rusk incorporated with black rice (Oryza sativa L.) for its physicochemical and functional properties, in-vitro starch digestibility, and anti-inflammatory efficacy.

BACKGROUND: The consumption of bakery goods is gradually increasing due to their accessibility, convenience, distinctive flavor, and affordability. The food industry is experimenting with novel methods of fortification, supplementation, enrichment, and adding value to bakery ingredients. The present investigation assessed the physicochemical, morphological, and sensorial properties, and anti-inflammatory efficacy of rusks with black rice incorporated. RESULTS: The addition of black rice flour significantly increased (P < 0.05) the total ash (from 1.34 to 1.78 g·kg-1 ), crude protein (from 5.68 to 75 g·kg-1 ), and total fat (from 11.93 to 12.80 g·kg-1 ) content but the carbohydrate content of the rusk decreased significantly (from 76.23 to 71.42 g·kg-1 ). Similarly, the phenolic and flavonoid content increased and showed excellent free-radical scavenging activity after black rice incorporation. The inclusion of black rice flour led to improved functional properties while decreasing the rate of starch digestion and the eGlycemic Index (eGI) score. The sensory scores declined after black rice incorporation but for all rusk samples acceptability was above the lowest level (i.e., ≥5). CONCLUSION: This study demonstrated that the incorporation of black rice flour into refined wheat flour can enhance the nutritional value of rusk and that it is possible to prepare rusk and other bakery goods using up to 30% black rice with taste and other sensory attributes similar to control rusk. © 2023 Society of Chemical Industry.

RWP-RK Domain 3 (OsRKD3) induces somatic embryogenesis in black rice.

BACKGROUND: Plants have the unique capability to form embryos from both gametes and somatic cells, with the latter process known as somatic embryogenesis. Somatic embryogenesis (SE) can be induced by exposing plant tissues to exogenous growth regulators or by the ectopic activation of embryogenic transcription factors. Recent studies have revealed that a discrete group of RWP-RK DOMAIN-CONTAINING PROTEIN (RKD) transcription factors act as key regulators of germ cell differentiation and embryo development in land plants. The ectopic overexpression of reproductive RKDs is associated with increased cellular proliferation and the formation of somatic embryo-like structures that bypass the need for exogenous growth regulators. However, the precise molecular mechanisms implicated in the induction of somatic embryogenesis by RKD transcription factors remains unknown. RESULTS: In silico analyses have identified a rice RWP-RK transcription factor, named Oryza sativa RKD3 (OsRKD3), which is closely related to Arabidopsis thaliana RKD4 (AtRKD4) and Marchantia polymorpha RKD (MpRKD) proteins. Our study demonstrates that the ectopic overexpression of OsRKD3, which is expressed preferentially in reproductive tissues, can trigger the formation of somatic embryos in an Indonesian black rice landrace (Cempo Ireng) that is normally resistant to somatic embryogenesis. By analyzing the transcriptome of induced tissue, we identified 5,991 genes that exhibit differential expression in response to OsRKD3 induction. Among these genes, 50% were up-regulated while the other half were down-regulated. Notably, approximately 37.5% of the up-regulated genes contained a sequence motif in their promoter region, which was also observed in RKD targets from Arabidopsis. Furthermore, OsRKD3 was shown to mediate the transcriptional activation of a discrete gene network, which includes several transcription factors such as APETALA 2-like (AP2-like)/ETHYLENE RESPONSE FACTOR (ERF), MYB and CONSTANS-like (COL), and chromatin remodeling factors associated with hormone signal transduction, stress responses and post-embryonic pathways. CONCLUSIONS: Our data show that OsRKD3 modulates an extensive gene network and its activation is associated with the initiation of a somatic embryonic program that facilitates genetic transformation in black rice. These findings hold substantial promise for improving crop productivity and advancing agricultural practices in black rice.

Black rice and its by-products: anthocyanin-rich extracts and their biological potential.

Recently, growing demand for products enriched with natural compounds that support human health has been observed. Black rice, its by-products, and residues are known to have in their composition a large amount of these compounds with biological potential, mainly anthocyanins. These compounds have reported effects on anti-obesity, antidiabetic, antimicrobial, anticancer, neuroprotective, and cardiovascular disease. Therefore, the extract from black rice or its by-products have great potential for application as ingredients in functional foods, supplements, or pharmacological formulations. This overview summarizes the methods employed for the extraction of anthocyanins from both black rice and its by-products. In addition, trends in applications of these extracts are also evaluated regarding their biological potential. Commonly, the extraction methods used to recover anthocyanins are conventional (maceration) and some emerging technologies (Ultrasound-Assisted Extraction - UAE, and Microwave-Assisted Extraction - MAE). Anthocyanin-rich extracts from black rice have presented a biological potential for human health. In vitro and in vivo assays (in mice) showed these compounds mainly with anti-cancer properties. However, more clinical trials are still needed to prove these potential biological effects. Extracts from black rice and its by-products have great potential in applying functional products with beneficial characteristics to humans and reducing agro-industrial residues.

Comparative analysis of the efficiency of seed protein profiles in assessing genetic variation and population structure among indigenous Manipur black rice cultivars.

BACKGROUND: The state of Manipur, North East India has distinct topology of hill and valley regions with vast agroclimatic variability, being considered as one of the centers of rice diversity. The indigenous Manipur black rice cultivars exhibit wide range of diversity in morphology, pericarp color, shape and size of grain, aroma, glutinous or non-glutinous features but remain less characterised. Many of these cultivars, such as those named Chakhao, are endowed with multiple health benefits due to high anthocyanins, and hold special importance for the local people. It is important to analyse the genetic diversity and population structure for this germplasm with unique allelic combinations to utilize in rice breeding programme. METHODS AND RESULTS: We characterized total soluble seed protein fractions to not only fingerprint the 45 indigenous black rice cultivars but assess their genetic relatedness. Cluster analyses generated mainly two groups, complemented by PCoA scatter plot ascertaining geographical distinction. The hill black rice were more diverse. The population structure analysis revealed seven subpopulations indicating high genetic variability. The 24 polymorphic bands were scored in the range of 127.8 to 10.3 kDa comprised of four protein fractions. Three polypeptide bands each were ascribed to known fractions of glutelins and prolamins, while one band each could be described for albumin and globulin fractions, besides other diagnostic bands. CONCLUSION: Some diverse cultivars were Amubi, Chedo Anal, Chipi Buh, Athebu, Poireton, BuPu Mui, Kotha Chahao II. These cultivars can be used in future black rice breeding programmes. This can further prevent genetic erosion and protect intellectual property rights.

Resistant starch from black rice, Oryza sativa L. var. ameliorates renal inflammation, fibrosis and injury in insulin resistant rats.

It has recently been reported that black rice (BR) extract has anti-obesity, anti-diabetic, and anti-osteoporosis effects. It has been shown to reduce obese-related kidney dysfunction in animal models. This study aimed to investigate the effect of resistant starch from BR (RS) on renal inflammation, oxidative stress, and apoptosis in obese insulin resistant rats. Male Wistar rats were divided into six groups: normal diet (ND), ND treated with 150 mg of RS (NDRS150), high-fat (HF) diet, HF treated with 100 and 150 mg of RS (HFRS100), (HFRS150), and HF treated with metformin as a positive control. Insulin resistance was shown in the HF rats by glucose intolerance, increased insulin, total area under the curve of glucose and homeostasis model assessment of insulin resistance and dyslipidemia. The resulting metabolic disturbance in the HF rats caused renal inflammation, fibrosis and apoptosis progressing to kidney injury and dysfunction. Prebiotic RS including anthocyanin from BR at doses of 100 and 150 mg ameliorated insulin resistance, dyslipidemia and liver injury. Treatment with RS reduced TGF-ß fibrotic and apoptotic pathways by inhibition of NF-κB and inflammatory cytokines which potentially restore kidney damage and dysfunction. In conclusion, prebiotic RS from BR ameliorated obesity induced renal injury and dysfunction by attenuating inflammatory, fibrotic, and apoptotic pathways in insulin resistant rats induced by HF.

Quality evaluation of different black rice varieties of northeastern region of India.

INTRODUCTION: Black rice (Oryza sativa L.), which is rich in polyphenols and flavonoids, is indigenous to Northeast India, specifically Manipur, and traditionally consumed for its protective effects on human health. Due to its economic value, it is crucial to evaluate the quality of different black rice varieties to authenticate their therapeutic and nutritional properties. OBJECTIVE: We aimed to evaluate the quality of pre- and post-marketed black rice samples by a validated high-performance thin layer chromatography method and determine variations of total phenolics and total flavonoids with antioxidant potential. MATERIAL AND METHODS: The ferulic acid, gallic acid, quercetin, and caffeic acid contents of three black rice varieties-Poireiton, Amubi, and Sempak-along with two marketed samples of Amubi from Manipur, India, were quantified based on standards. Antioxidant potential was measured by the 2,2-diphenyl-1-picryl-hydrazyl hydrate free radical scavenging assay. RESULTS: The highest and lowest relative biomarker contents were found in hydroalcoholic extracts of Amubi [caffeic acid (1.43% w/w), ferulic acid (1.15% w/w), quercetin (0.6% w/w), and gallic acid (0.39% w/w)] and the marketed sample Var. Amubi from Kakching District, respectively. Pearson's correlation coefficient of antioxidant potential with phenolic and flavonoid content showed a moderate to strong correlation for all samples. CONCLUSION: This validated, rapid, accurate standardization method for black rice varieties will be beneficial for the quality evaluation of black rice and its derived products. It will also be helpful to authenticate the nutritional benefits for the consumers.

Mineral elements and their relation to anthocyanin content in pigmented rice plants using definitive screening design and self-organizing maps.

BACKGROUND: Mineral elements are nutrients required by an organism to perform functions necessary for survival. Stress-induced metabolism following nutritional stress has been reported to increase levels of anthocyanin. However, the role of mineral elements commonly found in soil and their contribution to the accumulation of anthocyanin content in rice plants is uncertain. RESULT: Amongst the ten mineral elements investigated, the cultivation of rice plants in clean sand showed that the Mg-, Se-, and Cu-treated plants had the highest accumulated anthocyanin content in the leaves, whereas B, Cr, and Se had the greatest effect on grains. Yield component data showed major positive effects from Mg, Cr, and B. The interaction of Zn*Se and Mg*Cu positively affected the anthocyanin content in grains. The self-organizing map indicated that the total anthocyanin content was relatively proportional to the concentration of Mn, B, and Cr, but disproportional to that of Se. However, rice plants with added Fe produced the smallest amount of total anthocyanin content, less than the control, in the four stages of rice growth. CONCLUSION: The appropriate concentrations of mineral elements in soil could promote the proliferation of anthocyanin content in rice plants and grains. © 2023 Society of Chemical Industry.

Black rice bran intake reduces phosphorylated tau levels and enhances insulin signaling in the brain of aged normal mice.

This study reports that black rice bran (BRB) intake for 50-52 consecutive weeks (∼12 months) reduces tau phosphorylation with a concomitant activation of insulin signaling and subsequent PI3K/AKT pathway in the brain of aged normal mice. BRB holds promise for preventing the formation of neurofibrillary tangles consisting of hyperphosphorylated tau, a pathological hallmark of Alzheimer's disease.

Evaluation of Anti-Hyperglycemia and Complications of Red and Black Thai Jasmine Rice Cultivars in Streptozotocin-Induced Diabetic Rats.

The phytochemical constituents of red (RR) and black (BR) rice extracts were determined using high-pressure liquid chromatography (HPLC). Phytochemical screening revealed the presence of catechin, rutin, isoquercetin, cyanidin 3-glucoside, cyanidin 3-O-rutinoside, peonidin and quercetin. The anti-diabetic activities of RR and BR extracts on diabetic complications were examined in a streptozotocin-induced diabetic rat model. Rats (n = 80) were divided into 10 groups (n = 8 rats per group). Healthy and diabetic RR or BR-treated groups received 10, 50, or 200 mg of RR or BR per kg of body weight daily for 45 days. The results demonstrated significantly improved glucose control in rats administered RR or BR, while triglyceride and cholesterol levels were reduced in the diabetic groups. Moreover, RR or BR treatment led to decreased levels of malondialdehyde, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and creatinine. Further, glutathione concentration was significantly increased in both serum and liver tissue from RR- and BR-treated diabetic rats.

Pre-gelatinization and cellulase addition improve fermentation performance and antioxidant activity of black rice wine.

BACKGROUND: Black rice contains a variety of bioactive substances that contribute to the high nutritional value of black rice wine (BRW). However, the dense bran layer of black rice retards the fermentation rate and reduces the dissolution of active components. Hence, this study aims to investigate the effects of pre-gelatinization (PG) before cooking and cellulase (CE) addition during fermentation on the fermentation performance of BRW and its antioxidant activity. RESULTS: PG combined with CE treatments (PGCE) increases the alcohol content, free amino acid content, volatile flavor content and total antioxidant activity of BRW by 90.81%, 15.36%, 38.05% and 19.56%, respectively, compared with the control group. Scanning electron microscopy, low-field nuclear magnetic resonance and texture properties analysis indicate that PG treatment increases gelatinization degree of starch during cooking, decreases bound water content in cooked black rice and promotes unbound water release. CE destroys the aleurone layer structure, facilitates the release of unbound water and the exposure of rice starch, thus increasing the reaction area and extravasation content significantly, which is beneficial to microbial growth and fermentation. Incomplete aleurone layer also promotes the dissolution of anthocyanins, phenols and other active substances, increasing the antioxidant activities of BRW. CONCLUSION: PG and CE treatments reduce the fermentation time and improve the quality of BRW by destroying the black rice structure. © 2022 Society of Chemical Industry.

Anthocyanin-rich fraction from black rice, Oryza sativa L. var. indica "Luem Pua," bran extract attenuates kidney injury induced by high-fat diet involving oxidative stress and apoptosis in obese rats.

Obesity is acknowledged as being a world health problem and increases the risk of several chronic diseases including chronic kidney disease. High-fat diet consumption and obesity-related renal disease show a close correlation with increased oxidative stress. Black rice bran extract, (BRE) Oryza sativa L. variety "Luem Pua" contains a high anthocyanin content. This study evaluated the effects of an anthocyanin-rich fraction from BRE on renal function and oxidative stress in obese rats. Male Wistar rats were fed a normal diet (ND) or high-fat diet (HF) for 16 weeks. After this, the rats were given either vehicle (HF), BRE 100 (HF100) or BRE 200 mg/kg/day (HF200) orally for 8 weeks. The HF rats had increased body weight, visceral fat weight, plasma glucose, cholesterol and triglycerides. These parameters were normalized following HF100 administration and showed a decreasing trend with HF200. Serum creatinine and renal cortical MDA were increased in the HF group but these effects were attenuated by BRE. Negative kidney injury and histopathology changes were observed following a HF, but treatment with BRE reversed these deleterious effects. These results suggest that BRE could be used as a food supplement to improve metabolic disturbance and prevent kidney dysfunction in cases of obesity.

Gastroprotective Activities of Ethanol Extract of Black Rice Bran (Oryza sativa L.) in Rats.

Black rice is a type of rice in the Oryza sativa L. species. There are numerous reports regarding the pharmacological actions of black rice bran, but scientific evidence on its gastroprotection is limited. This study aimed to evaluate the gastroprotective activities of black rice bran ethanol extract (BRB) from the Thai black rice variety Hom Nil (O. sativa L. indica) as well as its mechanisms of action, acute oral toxicity in rats, and phytochemical screening. Rat models of gastric ulcers induced by acidified ethanol, indomethacin, and restraint water immersion stress were used. After pretreatment with 200, 400, and 800 mg/kg of BRB in test groups, BRB at 800 mg/kg significantly inhibited the formation of gastric ulcers in all gastric ulcer models, and this inhibition seemed to be dose dependent in an indomethacin-induced gastric ulcer model. BRB could not normalize the amount of gastric wall mucus, reduce gastric volume and total acidity, or increase gastric pH. Although BRB could not increase NO levels in gastric tissue, the tissue MDA levels could be normalized with DPPH radical scavenging activity. These results confirm the gastroprotective activities of BRB with a possible mechanism of action via antioxidant activity. The major phytochemical components of BRB comprise carotenoid derivatives with the presence of phenolic compounds. These components may be responsible for the gastroprotective activities of BRB. The 2000 mg/kg dose of oral BRB showed no acute toxicity in rats and confirmed, in part, the safe uses of BRB.

Effect of heat-moisture treatment of germinated black rice on the physicochemical properties and its utilization by lactic acid bacteria.

The heat susceptibility of starch granule structure has been considering as significant limitation of germinated black rice (GBR) using in food processing industry. Therefore, this study aimed to improve the physicochemical and antioxidation property as well as its effect on the probiotics of GBR by heat moisture treatment (HMT). Black rice germinated at 37.5 °C for 12, 24, and 36 h were studied. Ultrastructural image of each sample was visualized through scanning electron microscope. The results illustrated 24 h-GBR retain its former shape with rough surface. Subsequently, 24 h-GBR was structurally modified by HMT with moisture levels of 20% and 25% for 1 and 2 h. The results showed that pasting properties of HMT-treated GBR were improved. This was particularly on, GBR using HMT condition of 25% moisture for 2 h decrease in breakdown viscosity was shown. Moreover, phenolic content of HMT-treated GBR was higher than those of GBR. Besides, the number of the Lactobacillus paracasei TOKAI 13 was increased in GBR and HMT-treated GBR with counts of 10.08 ± 0.83 Log CFU/ml and 9.31 ± 0.33 Log CFU/ml, respectively, with significant increases in antioxidant property. Therefore, the HMT-GBR could be utilized as an alternative functional ingredient in food processing products.

Application of pulverization and thermal treatment to pigmented broken rice: insight into flour physical, functional and product forming properties.

The utilization of rice for food purposes involves pulverization and thermal processing which may affect its quality characteristics. Hence pigmented broken rice was processed in plate mill and hammer mill followed by thermal treatment by toasting to study the physical, and functional characteristics and their effect on rice noodle quality. Results showed that plate milled rice flour showed high concentration of particles with size below 148 µm particle (44%), increased redness (21%), bulk density (17%), sedimentation value (75%), damaged starch (72%), peak viscosity (17%), and caused microstructural changes compared to the hammer mill. The toasting of plate milled red and black rice flour caused an insignificant influence on particle size, color, and bulk density. However, it increased the sedimentation value to 134% and 94% and damaged starch by 44% and 19% in red and black rice flour respectively. Further, a reduction in peak viscosity (22%) in red, and increase (16%) in black, along with microstructural changes were also observed. The rice noodle prepared using plate milled, and toasted red rice flour was sensorily acceptable and exhibited excellent textural properties. The study showed that plate milling and thermal treatment significantly affect the quality characteristics of pigmented rice flour and end-product quality.

Benefits of Anthocyanin-Rich Black Rice Fraction and Wood Sterols to Control Plasma and Tissue Lipid Concentrations in Wistar Kyoto Rats Fed an Atherogenic Diet.

Background: This study reports on the relative effects of administrating a cyanidin-3-O-glucoside-rich black rice fraction (BRF), a standardized wood sterol mixture (WS), and a combination of both to lower plasma and target tissue lipid concentrations in Wistar Kyoto (WKY) rats fed atherogenic diets. Methods: Male WKY (n = 40) rats were randomly divided into five groups, which included a nonatherogenic control diet and atherogenic diets that included a positive control and atherogenic diets supplemented with BRF or WS, respectively, and a combination of both BRF + WS. Plasma and target tissue liver, heart and aorta cholesterol, and triacylglycerides (TAG) content were also measured. Results: Rats fed atherogenic diets exhibited elevated hyperlipidemia compared to counterparts fed nonatherogenic diets (p < 0.001); this effect was mitigated by supplementing the atherogenic diets with BRF and WS, respectively (p < 0.05). Combining BRF with WS to enrich the supplement lowered cholesterol similar to the WS effect (p < 0.05) and lowered TAG characteristic to the BRF effect (p < 0.05). Conclusions: Rats fed diets containing BRF or WS effectively mitigate the hypercholesterolemia and elevated TAG induced by feeding an atherogenic diet. The benefit of adding BRF + WS together is relevant to the lipid parameter measured and is target tissue-specific.

Black rice with giant embryo ameliorates serum C-reactive protein in adults with metabolic syndrome.

Metabolic syndrome is well known to increase the risk of cardiovascular diseases. We have reported that phytochemicals rich black rice with giant embryo reduced fat mass and metabolic disorders in an animal model. However, such effects have not been evaluated in humans. Subjects with metabolic syndrome (n = 49, 38 male, 44.3 ± 6.1 years) were randomly assigned into two groups and ingested roasted black-rice with giant embryo (BR, n = 26, 20 male) or white-rice (WR, n = 23, 18 male) powders mixed with water for breakfast for three months. Subjects were evaluated for various metabolic parameters before and after intervention. All parameters were not significantly different between groups before starting the intervention. After three months of consumption of either BR or WR, changes of body weight in BR vs WR groups (-1.54 kg vs -1.29 kg, p = 0.649) as well as waist circumference (-1.63 cm vs -1.02 cm, p = 0.365) were not significantly different between groups. However, changes in highly-sensitive C reactive proteins in BR vs WR groups (-0.110 mg/dl vs 0.017 mg/dl, p = 0.003) had significant differences. Three months of meal replacement with BR had a significant reduction of highly-sensitive C reactive protein compared to those with WR in adults with metabolic syndrome.

Development of lightly milled black rice with easy cooking and retaining health benefits.

Consumers are reluctant to eat pigmented rice due to cooking difficulties and harder texture than white rice. In this study, paddy samples of black rice (Hom Nil cultivar) were milled for 0, 10, 30, 60 and 100 s and degree of milling (DOM) ~ 0, 6, 12, 22 and 30% were obtained. Head rice yield, physicochemical properties, cooking qualities, nutrients, resistant starch content, antioxidant properties, and sensorial qualities were studied. Milling at 10 s (DOM ~ 6%) did not remove all bran fractions. Head rice yield retained at 70.33%. Lightness (L*) and redness (a*) of black rice remained constant until DOM ~ 20% but yellowness (b*) gradually increased. Nutrients were embedded at different locations in grain kernels. All nutrients decreased with DOM but in different extents. Milling at 10 s generated loss of anthocyanin (70%), fat (44%), ash (33%) and phenolic compounds (31%). Comparably tiny losses were observed in protein (15%) and dietary fiber (25%). However, cooking qualities of black rice were substantially improved. Cooking time reduced from 22 to 15 min with increases in water uptake ratio and volume expansion ratio. Additionally cooked black rice had impressively softer texture. Panelist appreciated the change in odor, flavor, texture attributes and palatability of the rice.

Transcriptome and Proteome Profiling of Different Colored Rice Reveals Physiological Dynamics Involved in the Flavonoid Pathway.

Black and red rice are rich in both anthocyanin and proanthocyanin content, which belong to a large class of flavonoids derived from a group of phenolic secondary metabolites. However, the molecular pathways and mechanisms underlying the flavonoid biosynthetic pathway are far from clear. Therefore, this study was undertaken to gain insight into physiological factors that are involved in the flavonoid biosynthetic pathway in rice cultivars with red, black, and white colors. RNA sequencing of caryopsis and isobaric tags for relative and absolute quantification (iTRAQ) analyses have generated a nearly complete catalog of mRNA and expressed proteins in different colored rice cultivars. A total of 31,700 genes were identified, of which 3417, 329, and 227 genes were found specific for red, white, and black rice, respectively. A total of 13,996 unique peptides corresponding to 3916 proteins were detected in the proteomes of black, white, and red rice. Coexpression network analyses of differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) among the different rice cultivars showed significant differences in photosynthesis and flavonoid biosynthesis pathways. Based on a differential enrichment analysis, 32 genes involved in the flavonoid biosynthesis pathway were detected, out of which only CHI, F3H, ANS, and FLS were detected by iTRAQ. Taken together, the results point to differences in flavonoid biosynthesis pathways among different colored rice cultivars, which may reflect differences in physiological functions. The differences in contents and types of flavonoids among the different colored rice cultivars are related to changes in base sequences of Os06G0162500, Os09G0455500, Os09G0455500, and Os10G0536400. Current findings expand and deepen our understanding of flavonoid biosynthesis and concurrently provides potential candidate genes for improving the nutritional qualities of rice.

New Functional Ingredients Based on Microencapsulation of Aqueous Anthocyanin-Rich Extracts Derived from Black Rice (Oryza sativa L.).

The aqueous anthocyanin-rich extract derived from black rice (Oryza sativa L.) was encapsulated by freeze drying using milk proteins and peptides as coating materials. The molecular modelling approach indicated that all major casein fractions and whey proteins were able to bind at least one anthocyanin molecule. The hydrophobic interactions and hydrogen bonding across the interfaces appeared to be mainly responsible for the stabilizations of the complexes formed between the coating material and bioactive compounds. Two dark purple colored powders, differentiated by the ratio of the encapsulation materials used, rich in phytochemicals were obtained, with an encapsulation efficiency of up to 99%. The powders were tested for antioxidant activity, cytocompatibility, and thermal stability. The morphological structure of the powders highlighted the presence of encapsulated anthocyanins. Both powders showed a remarkable antioxidant activity of about 46 mM Trolox/g D.W., and cytocompatibility on the L929 fibroblast culture. At certain concentrations, both powders stimulated cell proliferation. The powders showed a good thermal stability between 75 and 100 °C for 15 min. The powders were tested in a food model system and checked for stability of phytochemicals during storage. The added value of the powders was demonstrated throughout the antioxidant activity, which remained unchanged during storage.

Evaluation of sensory, physicochemical properties and Consumer preference of black rice and their products.

This study was aimed to evaluate the physicochemical, textural, sensory and antioxidative attributes of various rice products such as boiled rice, beaten rice, popped rice, puffed rice and raw milled rice, prepared from the Indian black rice cultivars Chakha (CH), Kalobhat (KB), Mamihunger (MA) and Manipuri Black (MN). A popular white rice variety Swarna Sub-1 (SW) was considered as control. Significant differences in most of the physicochemical and cooking parameters of raw rice were observed across different cultivars. The head rice recovery, amylose content, elongation ratio (ER) and kernel length after cooking of MA were most satisfactory among the black rice cultivars and are found to be 50.67%, 17.6%, 1.87 and 10.10 mm respectively, while popped rice of MA recorded highest length (10.83 mm) and elongation ratio (ER; 2.01). MA showed the highest adhesiveness (11.18 mJ) in boiled rice but hardness (183.53 N) was medium in raw rice. Other textural quality varied differentially according to the various products and cultivars. The highest a* value was obtained from puffed rice of MA (6.61) but L value was highest in raw rice of MN. Popped and boiled rice of MA displayed higher DPPH-antioxidant activity (88.74% and 84.74% respectively) as compared to all other products. The raw rice of KB registered higher anthocyanin (57.23 mg/100 g) content while boiled rice of SW recorded the least (0.21 mg/100 g). A survey on the consumer preference of these products indicated that boiled rice was usually preferred in lunch and dinner by most of the consumers whiles other products in breakfast. With respect to most of the traits, MA showed the good potential for rice Industry as well as for breeding material.