Bioactive compounds in rice on Italian market: pigmented varieties as a source of carotenoids, total phenolic compounds and anthocyanins, before and after cooking

Bioaccessibility of phenolic compounds during simulated gastrointestinal digestion of black rice (Oryza sativa L., cv. Artemide)

Black rice can be defined as a natural functional food, due to its high content of antioxidant polyphenols, particularly anthocyanins and phenolic acids. The objective of this study was to assess the fate of the main phenolic compounds in cooked black rice through in vitro digestion, defining both their soluble and insoluble fractions at the different digestive phases. The digestion significantly impacted the stability of the molecules, more specifically anthocyanins, which tend to be stable up to the gastric level and then degrade during the intestinal phase; after gastrointestinal digestion the total recovery of cyanidin-3-O-glucoside, the most abundant anthocyanin, was 52.4 %. On the other hand, bioaccessibility of free phenolic acids progressively increases up to the intestinal phase, with a total recovery of protocatechuic acid, the most represented phenolic acid in free form, of 84.3 %. Finally bound phenolic acids were not significantly released during the digestive phases.

Recent insights into anthocyanin biosynthesis, gene involvement, distribution regulation, and domestication process in rice (Oryza sativa L.)

Anthocyanins are water-soluble natural pigments found broadly in plants. As members of the flavonoid family, they are widely distributed in various tissues and organs, including roots, leaves, and flowers, responsible for purple, red, blue, and orange colors. Beyond pigmentation, anthocyanins play a role in plant propagation, stress response, defense mechanisms, and human health benefits. Anthocyanin biosynthesis involves a series of conserved enzymes encoded by structural genes regulated by various transcription factors. In rice, anthocyanin-mediated pigmentation serves as an important morphological marker for varietal identification and purification, a critical nutrient source, and a key trait in studying rice domestication. Anthocyanin biosynthesis in rice is regulated by a ternary conserved MBW transcriptional complexes comprising MYB transcription factors (TFs), basic-helix-loop-helix (bHLH) TFs, and WD40 repeat protein, which activate the expression of structure genes. Wild rice (Oryza rufipogon) commonly has purple hull, purple stigma, purple apiculus, purple leaf, and red pericarp due to the accumulations of anthocyanin or proanthocyanin. However, most cultivated rice (Oryza sativa) varieties lose the anthocyanin phenotypes due to the function variations of some regulators including OsC1, OsRb, and Rc and the structure gene OsDFR. Over the past decades, significant progress has been made in understanding the molecular and genetic mechanisms of anthocyanin biosynthesis. This review summarizes research progress in rice anthocyanin biosynthetic pathways, genes involvements, distribution regulations, and domestication processes. Furthermore, it discusses future prospects for anthocyanin biosynthesis research in rice, aiming to provide a theoretical foundation for future investigations and applications, and to assist in breeding new rice varieties with organ-targeted anthocyanin deposition.

Impact of traditional and innovative cooking techniques on Italian black rice (Oryza sativa L., Artemide cv) composition

Due to its high polyphenol content, black rice plays a significant role in good nutrition; however, these antioxidant compounds are affected by heat treatments required for the rice consumption. The aim of this work was to investigate how cooking affects the composition of Artemide black rice, comparing innovative methods, such as sous vide, with traditional domestic techniques (risotto and pilaf). Proteins and ashes were not affected by cooking, except for pilaf rice, where a 42 % ashes decrease was observed; fiber content increased after all cooking methods, reaching a 29 % increase in the risotto. Antioxidant activity, total polyphenols, anthocyanins and proanthocyanidins were reduced on average of 40 %, 34 %, 43 % and 39 %, respectively. Individual anthocyanins decreased, while phenolic acids and other flavonoids presented different behaviours, also depending if considered in their free or bound form. Cyanidin-3-O-glucoside was reduced up to 56 % in the sous vide cooked rice at 99 °C, and only by 45 % and 37 % in the risotto and sous vide cooked rice at 89 °C, respectively. Traditional risotto preparation and the innovative sous vide cooking at 89 °C also maintained the highest antioxidant polyphenols content, saving 63 % of the antioxidant activity in respect to the raw black rice. Concluding, these last techniques can be suggested for a better preservation of bioactive compounds.

Comparative Metabolic Profiling of Different Colored Rice Grains Reveals the Distribution of Major Active Compounds and Key Secondary Metabolites in Green Rice

Pigmented rice grains are important resources for health and nutritional perspectives. Thus, a thorough dissection of the variation of nutrients and bioactive metabolites in different colored rice is of global interest. This study applied LC-MS-based widely targeted metabolite profiling and unraveled the variability of metabolites and nutraceuticals in long grain/non-glutinous black (BR), red (RR), green (GR), and white rice (WR) grains. We identified and classified 1292 metabolites, including five flavonoid compounds specific to BR. The metabolite profiles of the four rice grains showed significant variation, with 275-543 differentially accumulated metabolites identified. Flavonoid (flavone, flavonol, and anthocyanin) and cofactor biosynthesis were the most differentially regulated pathways among the four rice types. Most bioactive flavonoids, anthocyanidins (glycosylated cyanidins and peonidins), phenolic acids, and lignans had the highest relative content in BR, followed by RR. Most alkaloids, amino acids and derivatives, lipids, and vitamins (B6, B3, B1, nicotinamide, and isonicotinic acid) had higher relative contents in GR than others. Procyanidins (B1, B2, and B3) had the highest relative content in RR. In addition, we identified 25 potential discriminatory biomarkers, including fagomine, which could be used to authenticate GR. Our results show that BR and RR are important materials for medicinal use, while GR is an excellent source of nutrients (amino acids and vitamins) and bioactive alkaloids. Moreover, they provide data resources for the science-based use of different colored rice varieties in diverse industries.

Whole Black Rice Flour Improves the Physicochemical, Glycemic, and Sensory Properties of Cracker Snacks

The present study describes the enhancement of the nutritional values of gluten-free rice crackers by adding whole black rice grain flour. The crackers were prepared by combining whole brown rice flour (WRF) and whole black rice flour (BRF) in ratios of 0% (WRC), 25% (25-BRC), 50% (50-BRC), 75% (75-BRC), and 100% (BRC). The resulting samples underwent in-vivo effects on postprandial blood glucose levels as well as physicochemical and sensory analysis. In comparison to WRC, the samples containing 100% added black rice flour presented higher nutritional qualities in terms of protein, by 16.61%, 8.64% for lipids, 5.61% for ash, 36.94% for crude fiber, 58.04% for total polyphenols, 95.49% for proanthocyanidins, and 88.07% for flavonoids. The addition of BRF had a suppressing effect on lightness (L*) and yellowness (b*), while redness (a*) increased. The results of the glycemic measurements confirmed that consumption of crackers made from brown or black whole-grain rice grain flour does not generate glycemic peaks above the limit of 30 mg/dL in baseline blood glucose levels. The results of developing rice crackers from black and brown flour blends showed promising physicochemical and nutritional properties and could provide a good alternative to wheat flour as a gluten-free product.

Functional Foods from Black Rice (Oryza sativa L.): An Overview of the Influence of Drying, Storage, and Processing on Bioactive Molecules and Health-Promoting Effects

Black rice (Oryza sativa) stands out for its high content of bioactive compounds with functional properties that play an important role in health benefits. The phytochemical level is affected by industrial processing due to its instability to the hydrothermal process. Studies about the influence of industrial processing on the phytochemical profile of black-rice-based foods are still scarce. This study carried out a comprehensive review of the influence of industrial applications on the bioactive compounds in food products based on black rice and their health-promoting effects. Most industrial processes such as drying, storage, cooking, and extrusion affect phytochemical content and antioxidant capacity. Alternatively, technologies such as fermentation, UV-C irradiation, and sprouting can maintain or improve the phytochemical content in black rice products.

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.

Development of an Ultrasound-Assisted Extraction Procedure for the Simultaneous Determination of Anthocyanins and Phenolic Acids in Black Beans

Beans are an essential source of nutritional components such as plant proteins, minerals and dietary fiber, as well as of antioxidants such as phenolic compounds. Phenolic compounds are praised for their biological activities and possible benefits on human health. Since no official methods are available for phenolic compound extraction, the optimization of extraction parameters via Response Surface Methodology (RSM) has become a commonly used methodological approach for reliable determinations. This study aimed to apply RSM to optimize the ultrasound-assisted extraction procedure of phenolic compounds, including anthocyanins, from black beans. A Generally Recognized As Safe solvent (ethanol) was used. Solvent concentration, extraction time, and solvent/sample ratio were optimized to maximize two responses: Total Anthocyanin Content (TAC) and Total Phenolic Content (TPC). An ethanol concentration of 64%, 30 min extraction time, and a 50 mL/g solvent/sample ratio were identified as the optimal extraction conditions. The TAC was 71.45 ± 1.96 mg cyanidin-3-O-glucoside equivalents 100 g-1 dm, and the TPC was 60.14 ± 0.89 mg gallic acid equivalents 100 g-1 dm. Among the pigmented phenolic compounds, cyanidin-3-O-glucoside and peonidin-3-O-glucoside were identified in the extracts. Regarding phenolic acids, caffeic, sinapic, and t-ferulic acids were detected.

The potential use of Indian rice flour or husk in fortification of pan bread: assessing bread's quality using sensory, physicochemical, and chemometric methods

Hassawi rice is an Indica variety cultivated in Saudi Arabia with a higher nutritional value than the commercial Basmati rice varieties. The present study has investigated the feasibility of combining Hassawi rice flour (HRF) or husk (HRHF), an abundant byproduct, with wheat flour to produce nutritious economical pan bread. To achieve this aim, the physicochemical properties of HRF and HRHF were assessed using techniques such as UPLC-tandem MS, ICP-OES, and colorimeter. The proximate composition (moisture, crude fiber, and ash) and mineral contents of HRHF are significantly (p < 0.05) higher than HRF. On the other hand, the compounds p-coumaric acid, vanillic acid, γ- and δ-tocotrienols, and γ-oryzanol were unique to HRF. We further determined the changes in sensory, technological, and physicochemical properties of wheat flour bread substituted with 5%, 10%, and 15% of HRF or HRHF. The rheological tests showed that the addition of HRF and HRHF increased dough development and stability time. Further, substituting wheat flour for HRF and HRHF at levels higher than 10% affected sensory attributes, such as color, taste, odor, flavor, and appearance. These changes, however, were not always at a significant level. The causes of the differences in properties between control and fortified bread samples were investigated by chemometric methods. Samples of bread + HRF at 5 and 10% had comparable overall profiles to the control. On the other hand, bread + HRHF samples proved to retain higher concentrations of bioactive molecules compared to the control bread. Our findings shed light on the possible use of rice husk fibers in baking goods, notably pan bread. Furthermore, by integrating rice husk fibers into baked goods, we may boost their health benefits while also contributing to the long-term use of agricultural waste.

Response Surface Methodology as an Experimental Strategy for Ultrasound-Assisted Extraction of Phenolic Compounds from Artichoke Heads

The accurate quantification of phenolic compounds (PCs) in foods has become mandatory for a reliable estimation of PCs dietary intake. However, the extraction step of these molecules from the food matrix is a challenging and complex task. To manage the current lack of an official or generally accepted procedure for the recovery of phenolics, the application of statistical and mathematical tools, such as the response surface methodology (RSM), that allow the optimization of extraction parameters and the acquisition of the best output, has become the analytical approach of choice. The aim of this study was to apply an RSM-optimized ultrasound-assisted procedure to extract phenolic compounds from artichoke (Cynara cardunculus L. var. scolymus (L.) Hegi, cultivar "Campagnano") heads. The effect of extraction time, temperature, and solvent-to-sample ratio on the profile and content of phenolic acids and flavonoids was investigated. The total phenolic content was 488.13 ± 0.56 mg GAE 100 g^-1 dry matter (dm) and total flavonoid content was 375.03 ± 1.49 mg CAT_eq 100 g^-1 dm when the optimum extraction conditions were set. The HPLC analysis showed that caffeoylquinic acid derivatives (i.e., cynarin and 1,5-O-dicaffeoylquinic acid) were the main compounds in globe artichokes. Caffeic and p-coumaric acids were also identified. In regard to flavonoids, only the flavone luteolin-7-O-glucoside was identified.

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.

Ultrasonic-assisted immersion of parboiled treatment improves head rice yield and nutrition of black rice and provides a softer texture of cooked black rice

Parboiling is gaining increasing attention as it can enhance the head rice yield (HRY) and nutritional quality of non-pigmented rice. The traditional parboiling process with high-temperature immersion requires a long immersion period and results in hard texture of cooked parboiled black rice (PBR), which may be addressed by ultrasound-assisted immersion. In this study, we evaluated the effect of power, time and temperature of ultrasonic immersion on the HRY, texture profile and nutritional quality of PBR. Proper ultrasound-assisted immersion could increase the HRY by about 20% and the GABA content by up to 133%, as well as reduce the arsenic and cadmium content by up to 61% and 79% relative to untreated black rice (UBR), respectively. Moreover, it could increase the content of essential minerals such as calcium, iron and zinc to some extent, and free and bound polyphenols, despite of a certain loss of anthocyanins. It could also improve the palatability of cooked rice. Furthermore, response surface experiments based on the Box-Behnken design were performed to obtain and validate the optimal conditions of ultrasound-assisted immersion (540 W, 45 min, 57 °C). On this basis, morphological changes might be one reason for the improved HRY, nutrition and texture of PBR compared with those of UBR, namely the disappearance of cracks near the aleurone layer and formation of new cracks in the interior of rice.

Phenolic Profile and In Vitro Antioxidant Activity of Different Corn and Rice Varieties

Celiac disease (CD) is an autoimmune disease. To date, the only universally recognized treatment for CD is the gluten-free diet (GFD). Despite the GFD, a state of inflammation and oxidative stress could remain at the intestinal level of celiac patients. Several components of the diet, such as phenolic compounds with known antioxidant properties, could play a protective role in the inflammatory state of patients with CD. The objective of this study was the characterization of the phenolic profile and the antioxidant capacity of pigmented cereals (rice and corn) from the Italian market and farms. Different in vitro methods were applied: Folin-Ciocalteu assay, pH differential method, DPPH assay, TEAC assay, and High-Performance Thin Layer Chromatography technique. According to the results, pigmented varieties are possible valuable sources of phenolic compounds and anthocyanins with high antioxidant activity. They could be used as alternative ingredients for the formulation of gluten-free products.

Evaluation of the Potential Anti-Inflammatory Activity of Black Rice in the Framework of Celiac Disease

Inflammation and oxidative stress are two mechanisms involved in the pathogenesis of celiac disease (CD). Since the direct effect of gliadin on the intestinal epithelia is less studied, the aims of this study were the development of a specific cellular model based on the use of gliadin as a pro-inflammatory stimulus and the evaluation of the potential antioxidant and anti-inflammatory properties of extracts from different black rice in the framework of CD. The rice extracts were in vitro digested, characterized in terms of phenolic compounds and antioxidant capacity, and tested on Caco-2 cells to investigate their inhibitory effect on Reactive Oxygen Species, the NF-κB transcription and the CXC chemokines (sICAM-1, IL-8, and CXCL-10). In addition, the role of the extracts in modulating the activation of epithelial cells in CD was confirmed by applying the K562(S) agglutination test. The black rice extracts showed inhibitory effects on the production of the oxidative and the inflammatory mediators considered, with particular reference to lymphocyte-attracting CXCL-10 both before and after digestion. The presence of anthocyanins and their digestion metabolites may account for the observed anti-inflammatory activity after in vitro digestion. This work provided preliminary data supporting the use of black rice as a healthy food or ingredient of food supplements for celiacs.

Food safety assessments of acrylamide formation and characterizations of flaky rolls enriched with black rice (Oryza sativa)

This study aims to investigate the physicochemical composition, textural parameters, and chemical constituent of flaky rolls incorporated with different proportions of black rice flour. According to farinographic characteristics, the addition of black rice flour could reduce the stability and increase the dough development time and water absorption (%). While for the extensographic properties, addition of black rice flour resulted in significantly different maximum resistance to extension (BU) and extensibility (cm) vs. the control. With the addition of black rice flour in flaky rolls, the crude protein, total dietary fiber (TDF), soluble dietary fiber (SDF), and insoluble dietary fiber (IDF) were significantly improved. Glucose released was much lower with 10 and 20% black rice than the control and 5% black rice because of the higher black rice inclusion. With increasing black rice incorporation, total anthocyanin content, and antioxidant capacity was also improved. The content of asparagine, acrylamide, hydroxymethylfurfural (HMF), furfural, methylglyoxal, and glyoxal in flaky rolls was also increased. The proper content of black rice flour (5%) could significantly enhance the stability of the dough properties; control the final volume, texture, and appearance; and retain good protein and fiber composition, antioxidant capacity, and overall acceptance of the flaky roll.

Photochemistry, Functional Properties, Food Applications, and Health Prospective of Black Rice

This review investigates black rice’s photochemistry, functional properties, food applications, and health prospects. There are different varieties of black rice available in the world. The origins of this product can be traced back to Asian countries. This rice is also known as prohibited rice, emperor’s rice, and royal’s rice. Black rice is composed of different nutrients including fiber, protein, carbohydrates, potassium, and vitamin B complex. It contains an antioxidant called anthocyanin and tocopherols. Antioxidants are found mostly in foods that are black or dark purple. Due to its nutritious density, high fiber level, and high antioxidant content, black rice is a good alternative to white and brown rice. Utilizing black rice in various foods can enhance the nutritional value of food and be transformed into functional food items. Many noncommunicable diseases (NCDs) can be prevented by eating black rice daily, including cancer cells, atherosclerosis, hypertension, diabetes, osteoporosis, asthma, digestive health, and stroke risk. This review aim was to discuss the role of nutritional and functional properties of black rice in the formation of functional food against different noncommunicable diseases.

Performance of Thermoplastic Extrusion, Germination, Fermentation, and Hydrolysis Techniques on Phenolic Compounds in Cereals and Pseudocereals

Bioactive compounds, such as phenolic compounds, are phytochemicals found in significant amounts in cereals and pseudocereals and are usually evaluated by spectrophotometric (UV-VIS), HPLC, and LC-MS techniques. However, their bioavailability in grains is quite limited. This restriction on bioavailability and bioaccessibility occurs because they are in conjugated polymeric forms. Additionally, they can be linked through chemical esterification and etherification to macro components. Techniques such as thermoplastic extrusion, germination, fermentation, and hydrolysis have been widely studied to release phenolic compounds in favor of their bioavailability and bioaccessibility, minimizing the loss of these thermosensitive components during processing. The increased availability of phenolic compounds increases the antioxidant capacity and favor their documented health promoting.

Stability evaluation of gardenia yellow pigment in the presence of different antioxidants or microencapsulating agents

The chemical instability of gardenia yellow pigment (GYP) limits its utilization in the food industry. In this study, the effects of different antioxidants (0.2% of tea polyphenols, sodium phytate, potassium citrate, and ascorbic acid) and microencapsulating agents (gum Arabic, maltodextrin, inulin, and gum Arabic/maltodextrin) on the degradation of GYP under different conditions (heat, light, and ferric iron) were evaluated. Then, the characteristic properties of microcapsules coated with gum Arabic/maltodextrin, gum Arabic/maltodextrin/tea polyphenols, maltodextrin, and maltodextrin/tea polyphenols were investigated. Furthermore, food models were simulated to evaluate the GYP stability of the microcapsules. The results showed that tea polyphenols, maltodextrin, and gum Arabic/maltodextrin significantly improved the GYP stability. Moreover, the presence of GYP in microcapsules was confirmed by nuclear magnetic resonance and Fourier transform infrared spectroscopy. In addition, GYP-MD/TP possessed high thermal stability under different cooking methods. PRACTICAL APPLICATION: Gardenia yellow pigment (GYP) is easily degraded under light and high-temperature conditions, which limits its applications in the food industry. This study will provide effective clues for expanding the practical applications of GYP in the natural pigment industry.

Does Plant Breeding for Antioxidant-Rich Foods Have an Impact on Human Health?

Given the general beneficial effects of antioxidants-rich foods on human health and disease prevention, there is a continuous interest in plant secondary metabolites conferring attractive colors to fruits and grains and responsible, together with others, for nutraceutical properties. Cereals and Solanaceae are important components of the human diet, thus, they are the main targets for functional food development by exploitation of genetic resources and metabolic engineering. In this review, we focus on the impact of antioxidants-rich cereal and Solanaceae derived foods on human health by analyzing natural biodiversity and biotechnological strategies aiming at increasing the antioxidant level of grains and fruits, the impact of agronomic practices and food processing on antioxidant properties combined with a focus on the current state of pre-clinical and clinical studies. Despite the strong evidence in in vitro and animal studies supporting the beneficial effects of antioxidants-rich diets in preventing diseases, clinical studies are still not sufficient to prove the impact of antioxidant rich cereal and Solanaceae derived foods on human

Anthocyanins: Traditional Uses, Structural and Functional Variations, Approaches to Increase Yields and Products' Quality, Hepatoprotection, Liver Longevity, and Commercial Products

Anthocyanins are water-soluble, colored compounds of the flavonoid class, abundantly found in the fruits, leaves, roots, and other parts of the plants. The fruit berries are prime sources and exhibit different colors. The anthocyanins utility as traditional medicament for liver protection and cure, and importance as strongest plants-based anti-oxidants have conferred these plants products different biological activities. These activities include anti-inflammation, liver protective, analgesic, and anti-cancers, which have provided the anthocyanins an immense commercial value, and has impelled their chemistry, biological activity, isolation, and quality investigations as prime focus. Methods in extraction and production of anthocyanin-based products have assumed vital economic importance. Different extraction techniques in aquatic solvents mixtures, eutectic solvents, and other chemically reactive extractions including low acid concentrations-based extractions have been developed. The prophylactic and curative therapy roles of the anthocyanins, together with no reported toxicity has offered much-needed impetus and economic benefits to these classes of compounds which are commercially available. Information retrieval from various search engines, including the PubMed®, ScienceDirect®, Scopus®, and Google Scholar®, were used in the review preparation. This imparted an outlook on the anthocyanins occurrence, roles in plants, isolation-extraction, structures, biosynthetic as well as semi- and total-synthetic pathways, product quality and yields enhancements, including uses as part of traditional medicines, and uses in liver disorders, prophylactic and therapeutic applications in liver protection and longevity, liver cancer and hepatocellular carcinoma. The review also highlights the integrated approach to yields maximizations to meet the regular demands of the anthocyanins products, also as part of the extract-rich preparations together with a listing of marketed products available for human consumption as nutraceuticals/food supplements.

Effect of Processing on Bioactive Compounds, Antioxidant Activity, Physicochemical, and Sensory Properties of Orange Sweet Potato, Red Rice, and Their Application for Flake Products

Orange sweet potato (OSP) and red rice (RR) are rich sources of health benefit-associated substances and can be conventionally cooked or developed into food products. This research approach was to closely monitor the changes of bioactive compounds and their ability as antioxidants from the native form to the food products which are ready to be consumed. Moreover, this research explored the individual carotenoids and tocopherols of raw and cooked OSP and RR and their developed flake products, and also investigated their antioxidant activity, physicochemical properties, and sensory properties. Simultaneous identification using the liquid chromatographic method showed that OSP, RR, and their flake products have significant amounts (µg/g) of β-carotene (278.58–48.83), α-carotene (19.57–15.66), β-cryptoxanthin (4.83–2.97), α-tocopherol (57.65–18.31), and also γ-tocopherol (40.11–12.15). Different responses were observed on the bioactive compound and antioxidant activity affected by heating process. Meanwhile, OSP and RR can be combined to form promising flake products, as shown from the physicochemical analysis such as moisture (5.71–4.25%) and dietary fiber (13.86–9.47%) contents, water absorption index (1.69–1.06), fracturability (8.48–2.27), crispness (3.9–1.5), and color. Those quality parameters were affected by the proportions of OSP and RR in the flake products. Moreover, the preference scores (n = 120 panelists) for the flakes ranged from slightly liked to indifferent. It can be concluded that OSP and RR are potential sources of bioactive compounds which could act as antioxidants and could be developed into flake products that meet the dietary and sensory needs of consumers.

The nutritional profile and human health benefit of pigmented rice and the impact of post-harvest processes and product development on the nutritional components: A review

Pigmented rice has attracted considerable attention due to its nutritional value, which is in large conferred by its abundant content of phenolic compounds, considerable micronutrient concentrations, as well as its higher resistant starch and thereby slower digestibility properties. A wide range of phenolic compounds identified in pigmented rice exhibit biological activities such as antioxidant activity, anti-inflammatory, anticancer, and antidiabetic properties. Post-harvest processes significantly reduce the levels of these phytochemicals, but recent developments in processing methods have allowed greater retention of their contents. Pigmented rice has also been converted to different products for food preservation and to derive functional foods. Profiling a large set of pigmented rice cultivars will thus not only provide new insights into the phytochemical diversity of rice and the genes underlying the vast array of secondary metabolites present in this species but also provide information concerning their nutritional benefits, which will be instrumental in breeding healthier rice. The present review mainly focuses on the nutritional composition of pigmented rice and how it can impact human health alongside the effects of post-harvest processes and product development methods to retain the ambient level of phytochemicals in the final processed form in which it is consumed.

Stability evaluation of gardenia yellow pigment in presence of different phenolic compounds

Gardenia yellow pigment (GYP) may undergo chemical degradation under different conditions resulting in color fading. This study investigated the effects of different phenolic compounds (caffeic acid, rosmarinic acid, tannic acid, epicatechin, chlorogenic acid, epigallocatechin, and epigallocatechin gallate) on the physical and chemical stability of GYP under light and different temperatures. Furthermore, food models with GYP/phenolic compounds were simulated to evaluate the GYP stability under different cooking methods. The addition of phenolic compounds, especially tannic acid, epigallocatechin gallate, epigallocatechin, and rosmarinic acid, significantly improved the GYP stability during light and thermal treatments. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy confirmed that the formation of hydrogen bonds between GYP and selected phenolic compounds (tannic acid, epigallocatechin gallate, epigallocatechin, and rosmarinic acid), which may lead to the enhancement of GYP stability. Moreover, these selected phenolic compounds provided potent protective effects on GYP under different cooking methods.

Modelling and Optimization of Ultrasound-Assisted Extraction of Phenolic Compounds from Black Quinoa by Response Surface Methodology

Phenolic compounds are currently the most investigated class of functional components in quinoa. However, great variability in their content emerged, because of differences in sample intrinsic and extrinsic characteristics; processing-induced factors; as well as extraction procedures applied. This study aimed to optimize phenolic compound extraction conditions in black quinoa seeds by Response Surface Methodology. An ultrasound-assisted extraction was performed with two different mixtures; and the effect of time; temperature; and sample-to-solvent ratio on total phenolic content (TPC) was investigated. Data were fitted to a second-order polynomial model. Multiple regression analysis and analysis of variance were used to determine the fitness of the model and optimal conditions for TPC. Three-dimensional surface plots were generated from the mathematical models. TPC at optimal conditions was 280.25 ± 3.94 mg of Gallic Acid Equivalent (GAE) 100 g⁻¹ dm upon extraction with aqueous methanol/acetone, and 236.37 ± 5.26 mg GAE 100 g⁻¹ dm with aqueous ethanol mixture. The phenolic profile of extracts obtained at optimal conditions was also investigated by HPLC. The two extracting procedures did not show different specificities for phenolic compounds but differed in the extraction yield.

Available technologies on improving the stability of polyphenols in food processing

Polyphenols are the most important phytochemicals in our diets and have received great attention due to their broad benefits for human health by suppressing oxidative stress and playing a protective role in preventing different pathologies such as cardiovascular disease, cancer, diabetes, and obesity. The stability of polyphenols depends on their environments of processing and storage, such as pH and temperature. A wide range of technologies has been developed to stabilize polyphenols during processing. This review will provide an overview of the stability of polyphenols in relation to their structure, the factors impacting the stability of polyphenols, the new products deriving from unstable polyphenols, and the effect of a series of technologies for the stabilization of polyphenols, such as chemical modification, nanotechnology, lyophilization, encapsulation, cold plasma treatment, polyphenol–protein interaction, and emulsion as a means of improving stability. Finally, the effects of cooking and storage on the stability of polyphenols were discussed.

The Potential of High-Anthocyanin Purple Rice as a Functional Ingredient in Human Health

Purple rice is recognized as a source of natural anthocyanin compounds among health-conscious consumers who employ rice as their staple food. Anthocyanin is one of the major antioxidant compounds that protect against the reactive oxygen species (ROS) that cause cellular damage in plants and animals, including humans. The physiological role of anthocyanin in plants is not fully understood, but the benefits to human health are apparent against both chronic and non-chronic diseases. This review focuses on anthocyanin synthesis and accumulation in the whole plant of purple rice, from cultivation to the processed end products. The anthocyanin content in purple rice varies due to many factors, including genotype, cultivation, and management as well as post-harvest processing. The cultivation method strongly influences anthocyanin content in rice plants; water conditions, light quantity and quality, and available nutrients in the soil are important factors, while the low stability of anthocyanins means that they can be dramatically degraded under high-temperature conditions. The application of purple rice anthocyanins has been developed in both functional food and other purposes. To maximize the benefits of purple rice to human health, understanding the factors influencing anthocyanin synthesis and accumulation during the entire process from cultivation to product development can be a path for success.

Supercritical carbon dioxide extraction of plant phytochemicals for biological and environmental applications - A review

Recently, supercritical fluid CO₂ extraction (SFE) has emerged as a promising and pervasive technology over conventional extraction techniques for various applications, especially for bioactive compounds extraction and environmental pollutants removal. In this context, temperature and pressure regulate the solvent density and thereby effects the yield, selectivity, and biological/therapeutic properties of the extracted components. However, the nature of plant matrices primarily determines the extraction mechanism based on either density or vapor pressure. The present review aims to cover the recent research and developments of SFE technique in the extraction of bioactive plant phytochemicals with high antioxidant, antibacterial, antimalarial, and anti-inflammatory activities, influencing parameters, process conditions, the investigations for improving the yield and selectivity. In another portion of this review focuses on the ecotoxicology and toxic metal recovery applications. Nonpolar properties of Sc-CO₂ create strong solvent strength via distinct intermolecular interaction forces with micro-pollutants and toxic metal complexes. This results in efficient removal of these contaminants and makes SFE technology as a superior alternative for conventional solvent-based treatment methods. Moreover, a compelling assessment on the therapeutic, functional, and solvent properties of SFE is rarely focused, and hence this review would add significant value to the SFE based research studies. Furthermore, we mention the limitations and potential of future perspectives related to SFE applications.

Cooking of Artemide Black Rice: Impact on Proximate Composition and Phenolic Compounds

The consumption of black rice has grown in recent years due to its particular organoleptic properties and high content of antioxidant polyphenols, which make it a sort of natural functional food. However, heat treatment applied during cooking can influence the content and the composition of antioxidant components, particularly anthocyanins, the main compounds of black rice, responsible for its color. The aim of this work was to evaluate the impact of different cooking techniques (boiling, microwaves oven, under pressure pot and risotto preparation) on the chemical and nutritional composition of the Italian Artemide black rice. Different cooking methods had significant and different impact on rice composition. Proximate composition was not affected by cooking, except for moisture, which increased, and fiber content, which decreased. Total polyphenols, total anthocyanin content, and antioxidant capacity were reduced; moreover, anthocyanins and phenolic acids determined by HPLC-DAD generally decreased, with the only exception of protocatechuic acid. The risotto preparation was the most useful cooking technique to preserve anthocyanins and antioxidant activity. Our results demonstrated the importance to study cooking methods and to evaluate their impact on rice characteristics, in order to preserve its nutritional and beneficial properties.

Effects of Dietary Inclusion of Canthaxanthin- and α-Tocopherol-Loaded Liposomes on Growth and Muscle Pigmentation of Rainbow Trout (Oncorhynchus mykiss)

Dietary inclusion of canthaxanthin, a common carotenoid pigment, has been long practiced in aquaculture to give the favorable flesh color in farmed salmonids. However, carotenoids are associated with limited solubility and poor physicochemical stability, and their dose in fish feed is widely regulated. In this study, we included canthaxanthin- and α-tocopherol-loaded liposomes into fish diets and evaluated the effects of supplemented fish feed on fish growth, color, nutrition, and canthaxanthin deposition in fillets of cultured rainbow trout (Oncorhynchus mykiss). The liposomes were fabricated using lecithin as phospholipids with the initial concentrations (IC = mcanthaxanthin/mlipids, % wt/wt) of canthaxanthin at 0.1%, 0.5%, and 1.0%. Particle size characterization showed that liposome mean sizes were 109.70 ± 6.36, 105.10 ± 8.41, and 109.20 ± 5.66 nm (mean ± SD; n = 3), respectively, corresponding with liposomes synthesized at canthaxanthin IC = 0.1%, IC = 0.5%, and IC = 1%. The polydispersity index (PDI) of all samples remained lower than 0.2. There were no significant differences in the mean size and PDI between blank lecithin liposome and canthaxanthin- and α-tocopherol-loaded liposomes. The encapsulation efficiency of canthaxanthin- and α-tocopherol-loaded liposomes decreased when increasing the concentration of canthaxanthin in lecithin liposomes, with EE% values of IC = 0.1%, IC = 0.5%, and IC = 1% being 85.3 ± 2.1, 72.9 ± 1.8, and 55.3 ± 2.6, respectively. For fish growth, at the end of the experiment, final weight was significantly higher in fish fed with diet supplemented with 1 g/kg canthaxanthin- and α-tocopherol-loaded liposomes (IC = 0.5%) in comparison to other experimental control groups. The difference in color of the salmon muscle was most apparent after two months of feeding. However, after three months, there was no noticeable change in the color score of the fish muscle, indicating saturation of color of the fish muscle. The above results suggest the potential of canthaxanthin- and a-tocopherol-loaded liposomes as the red pigment in fish aquaculture.

Functional Components and Anti-Nutritional Factors in Gluten-Free Grains: A Focus on Quinoa Seeds

Quinoa (Chenopodium quinoa Willd.) has recently received increasing interest from both scientists and consumers due to its suitability in gluten-free diets, its sustainability, and its claimed superfood qualities. The aim of this paper is to systematically review up-to-date studies on quinoa functional components and anti-nutritional factors, in order to define a baseline for food scientists approaching the investigation of quinoa phytochemicals and providing evidence for the identification of healthier sustainable foods. State of the art evaluations of phytochemical contents in quinoa seeds were obtained. It emerged that phenolic compounds are the most investigated functional components, and spectrophotometric methods have been mostly applied, despite the fact that they do not provide information about single components. Saponins are the most studied among anti-nutritional factors. Betalains, tannins, and phytoecdysteroids have been poorly explored. Information on factors affecting the phytochemical content at harvesting, such as quinoa ecotypes, crop geographical location and growing conditions, are not always available. A comprehensive characterization, encompassing several classes of functional components and anti-nutritional factors, is mainly available for quinoa varieties from South America. However, defining a standard of quality for quinoa seeds is still challenging and requires a harmonization of the analytical approaches, among others.

Impact of Fermentation on Phenolic Compounds and Antioxidant Capacity of Quinoa

Quinoa (Chenopodium quinoa Willd.) is increasingly singled out as a healthy food with an excellent nutritional profile. Besides being suitable for gluten-free diets, it is rich in proteins of excellent quality and is a good source of minerals and vitamins, as well as of natural antioxidants, such as phenolic compounds. The aim of this work is to present how fermentation can affect phenolic compound content and antioxidant capacity of quinoa. It emerged that fermentation can be used to increase phenolic compound content and antioxidant capacity in both quinoa seeds and flours. The use of fermented quinoa flours allowed obtaining bread and pasta richer in phenolic compounds and with a greater antioxidant capacity. Fungi are the main starters used in quinoa seed fermentation, while Lactobacillus strains have been applied to produce sourdoughs. Quinoa has been also fermented to obtain yogurt-like beverages with a higher content in phenolic compounds and a greater antioxidant activity. Strains of Lactobacillus sp. and Bifidobacterium sp. have been used as starters.

Black rice (Oryza sativa L.) processing: Evaluation of physicochemical properties, in vitro starch digestibility, and phenolic functions linked to type 2 diabetes

Black rice is recognized for managing diabetes in Chinese folk medicine. Therefore, the present study investigates the effect of thermal treatments and the succeeding cooking on black rice physicochemical properties, phenolic composition, total antioxidant activity (TAA), enzymes and glycation inhibition in addition to starch digestibility. Thermal decomposition of anthocyanin and cyanidin-3-glucoside was evident across all processing methods and reflected in increasing levels of protocatechuic acid, while proanthocyanidins (TPAC) were susceptible to cooking. Roasting of grains sustained total phenolics (TPC), flavonoids (TFC), TPAC, and antilipase activity. Additionally, the combined effect of frying and cooking diminished TFC, TPAC, and α-glucosidase inhibition. The thermally treated grains showed pronounced activity against α-amylase, α-glucosidase, and glycation, whereas their cooked counterparts reduced the estimated glycemic index (eGI), and enhanced resistant starch (RS). Processed grains chrominance, TAA, and apparent amylose content (AAC) showed a significant correlation with phenolics. These findings are demonstrating that black rice processing is favorable for the dietary management of metabolic disorders such as diabetes and hyperlipidemia.

Carotenoids in Cancer Apoptosis-The Road from Bench to Bedside and Back

An incidence and mortality of cancer are rapidly growing worldwide, especially due to heterogeneous character of the disease that is associated with irreversible impairment of cellular homeostasis and function. Targeting apoptosis, one of cancer hallmarks, represents a potent cancer treatment strategy. Carotenoids are phytochemicals represented by carotenes, xanthophylls, and derived compounds such as apocarotenoids that demonstrate a broad spectrum of anti-cancer effects involving pro-apoptotic signaling through extrinsic and intrinsic pathways. As demonstrated in preclinical oncology research, the apoptotic modulation is performed at post-genomic levels. Further, carotenoids demonstrate additive/synergistic action in combination with conventional oncostatic agents. In addition, a sensitization of tumor cells to anti-cancer conventional treatment can be achieved by carotenoids. The disadvantage of anti-cancer application of carotenoids is associated with their low solubility and, therefore, poor bioavailability. However, this deficiency can be improved by using nanotechnological approaches, solid dispersions, microemulsions or biofortification that significantly increase the anti-cancer and pro-apoptotic efficacy of carotenoids. Only limited number of studies dealing with apoptotic potential of carotenoids has been published in clinical sphere. Pro-apoptotic effects of carotenoids should be beneficial for individuals at high risk of cancer development. The article considers the utility of carotenoids in the framework of 3P medicine.

Review of Distribution, Extraction Methods, and Health Benefits of Bound Phenolics in Food Plants

Phenolic compounds are important functional bioactive substances distributed in various food plants. They have gained wide interest from researchers due to their multiple health benefits. There are two forms of phenolic compounds: free form and bound form. The latter is also called bound phenolics (BPs), which are found mainly in the cell wall and distributed in various tissues/organs of the plant body. They can either chemically bind to macromolecules and food matrixes or be physically entrapped in food matrixes and intact cells. Various isolation methods, including chemical, biological, and physical methods, have been employed to extract BPs from plants. BPs have been shown to have strong biological activities, including antioxidant, probiotic, anticancer, anti-inflammation, antiobesity, and antidiabetic effects as well as beneficial effects on central nervous system diseases. This review summarizes research findings on these topics to help in better understanding of BPs and provide comprehensive information on their health effects.

The Nutritional Value of Non-Traditional Gluten-Free Flakes and Their Antioxidant Activity

Nowadays, there is a growing interest for foods with a lower sugar content and rich in fiber and biologically active substances. The main purpose of this study was to prepare flakes from non-traditional pigmented cereals (Oryza sativa, Chenopodium quinoa, and Eragrostistef) and to analyze their fibre, sugar, and in vitro digestibility values. Regarding phenolic antioxidants (soluble, soluble conjugated, and insoluble bound fractions), their content and antioxidant activity were measured using spectrophotometry and high performance liquid chromatography (HPLC) methods. Hydrothermally treated grains resulted in flakes with higher total dietary fibre contents (11.1–24.4%), quinoa and teff flakes were rich in maltose (up to 42.0 mg/g). Non-traditional flakes had lower in vitro digestibility, but conversely, they exhibited the highest phenolic contents corresponding with the highest antioxidant activity values (up to 2.33 mg Gallic acid equivalent/g of total phenolic content and 1.59 mg Trolox equivalent/g for 2,2-diphenyl-1-picrylhydrazyl (DPPH) in case of brown teff). Among free phenolics, the main contributors to an antioxidant activity were p-coumaric, o-coumaric, and gallic acids (r > 0.8186); among the soluble conjugated fractions, they were epigallocatechin, epicatechin, caffeic, and vanillic acids (r > 0.5935); while caffeic, protocatechuic, and ferulic acids (r > 0.5751) were the main contributors among the insoluble bound phenolics.

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.

Gluten-Free Alternative Grains: Nutritional Evaluation and Bioactive Compounds

Interest in gluten-free grains is increasing, together with major incidences of celiac disease in the last years. Since to date, knowledge of the nutritional and bioactive compounds profile of alternative gluten-free grains is limited, we evaluated the content of water-soluble (thiamine and riboflavin) and liposoluble vitamins, such as carotenoids and tocols (tocopherols and tocotrienols), of gluten-free minor cereals and also of pseudocereals. The analysed samples showed a high content of bioactive compounds; in particular, amaranth, cañihua and quinoa are good sources of vitamin E, while millet, sorghum and teff (Eragrostis tef, or William’s Lovegrass) are good sources of thiamine. Moreover, millet provides a fair amount of carotenoids, and in particular of lutein. These data can provide more information on bioactive compounds in gluten-free grains. The use of these grains can improve the nutritional quality of gluten-free cereal-based products, and could avoid the monotony of the celiac diet.

Improvement of Quality Properties and Shelf Life Stability of New Formulated Muffins Based on Black Rice

Effects of partial (50%) and total replacement of wheat flour with black rice flour on the phytochemical, physico-chemical, sensorial, and textural properties of muffins were studied. Partial or total replacement of wheat flour with black rice flour in muffins improved their nutritional and antioxidative properties with a positive effect on microbiological and color stability during the storage period in accelerated conditions. The low gluten muffins had an anthocyanin content of 27.54 ± 2.22 mg cyanidin-3-glucoside (C3G)/100 g dry weight (DW), whereas the gluten free muffins had 46.11 ± 3.91 mg C3G/100 g DW, with significant antioxidant values. Retention of 60% and 64% for anthocyanins and 72% and 80% for antioxidant activity after baking was found. The fracturability and hardness scores increased with the addition of black rice flour, whereas firmness and chewiness increased for gluten free muffins. The confocal analysis revealed a tendency of glucidic components to aggregate, with gathers of small bunches of black rice starch granules comprising anthocyanin. The results allowed designing two new value added bakery products, low and free gluten muffins, with significant high amounts of bioactive compounds, suggesting the functional potential of black rice flour.