Bioactive compounds from by-products of rice cultivation and rice processing: Extraction and application in the food and pharmaceutical industries

Overexpression of ZlMYB1 and ZlMYB2 increases flavonoid contents and antioxidant capacity and enhances the inhibition of α-glucosidase and tyrosinase activity in rice seeds

Anthocyanins are natural flavonoids with a high antioxidant power and many associated health benefits, but most rice produce little amounts of these compounds. In this study, 141 MYB transcription factors in 15 chromosomes, including the nucleus-localised ZlMYB1 (Zla03G003370) and ZlMYB2 (Zla15G015220), were discovered in Zizania latifolia. Overexpression of ZlMYB1 or ZlMYB2 in rice seeds induced black pericarps, and flavonoid content, antioxidant capacity, and α-glucosidase and tyrosinase inhibition effects significantly increased compared to those in the control seeds. ZlMYB1 and ZlMYB2 overexpression induced the upregulation of 764 and 279 genes, respectively, and the upregulation of 162 and 157 flavonoids, respectively, linked to a black pericarp phenotype. The expression of flavonoid 3'-hydroxylase and UDP-glycose flavonoid glycosyltransferase, as well as the activities of these enzymes, increased significantly in response to ZlMYB1 or ZlMYB2 overexpression. This study systematically confirmed that the overexpression of ZlMYB1 and ZlMYB2 promotes flavonoid biosynthesis (especially of anthocyanins) in rice.

Aflatoxins in the rice production chain: A review on prevalence, detection, and decontamination strategies

Rice (Oryza sativa L.) is one of the most consumed cereals that along with several important nutritional constituents typically provide more than 21% of the caloric requirements of human beings. Aflatoxins (AFs) are toxic secondary metabolites of several Aspergillus species that are prevalent in cereals, including rice. This review provides a comprehensive overview on production factors, prevalence, regulations, detection methods, and decontamination strategies for AFs in the rice production chain. The prevalence of AFs in rice is more prominent in African and Asian than in European countries. Developed nations have more stringent regulations for AFs in rice than in the developing world. The contamination level of AFs in the rice varied at different stages of rice production chain and is affected by production practices, environmental conditions comprising temperature, humidity, moisture, and water activity as well as milling operations such as de-husking, parboiling, and polishing. A range of methods including chromatographic techniques, immunochemical methods, and spectrophotometric methods have been developed, and used for monitoring AFs in rice. Chromatographic methods are the most used methods of AFs detection followed by immunochemical techniques. AFs decontamination strategies adopted worldwide involve various physical, chemical, and biological strategies, and even using plant materials. In conclusion, adopting good agricultural practices, implementing efficient AFs detection methods, and developing innovative aflatoxin decontamination strategies are imperative to ensure the safety and quality of rice for consumers.

Stability and Composting Behaviour of PLA-Starch Laminates Containing Active Extracts and Cellulose Fibres from Rice Straw

The stability and composting behaviour of monolayers and laminates of poly (lactic acid) (PLA) and starch with and without active extracts and cellulose fibres from rice straw (RS) were evaluated. The retrogradation of the starch throughout storage (1, 5, and 10 weeks) gave rise to stiffer and less extensible monolayers with lower water vapour barrier capacity. In contrast, the PLA monolayers, with or without extract, did not show marked changes with storage. However, these changes were more attenuated in the bilayers that gained water vapour and oxygen barrier capacity during storage, maintaining the values of the different properties close to the initial range. The bioactivity of the active films exhibited a slight decrease during storage, so the antioxidant capacity is better preserved in the bilayers. All monolayer and bilayer films were fully composted within 90 days but with different behaviour. The bilayer assembly enhanced the biodegradation of PLA, whose monolayer exhibited a lag period of about 35 days. The active extract reduced the biodegradation rate of both mono- and bilayers but did not limit the material biodegradation within the time established in the Standard. Therefore, PLA-starch laminates, with or without the valorised fractions from RS, can be considered as biodegradable and stable materials for food packaging applications.

Molecular and metabolic insights into purplish leaf coloration through the investigation of two mulberry (Morus alba) genotypes

BACKGROUND

Leaf coloration in plants, attributed to anthocyanin compounds, plays a crucial role in various physiological functions, and also for pharmaceutical and horticultural uses. However, the molecular mechanisms governing leaf coloration and the physiological significance of anthocyanins in leaves remain poorly understood.

RESULTS

In this study, we investigated leaf color variation in two closely related mulberry genotypes, one with purplish-red young leaves (EP) and another with normal leaf color (EW). We integrated transcriptomic and metabolomic approaches to gain insights into the metabolic and genetic basis of purplish-red leaf development in mulberry. Our results revealed that flavonoid biosynthesis, particularly the accumulation of delphinidin-3-O-glucoside, is a key determinant of leaf color. Additionally, the up-regulation of CHS genes and transcription factors, including MYB family members, likely contributes to the increased flavonoid content in purplish-red leaves.

CONCLUSION

These findings enhance our understanding of the molecular mechanisms responsible for the purplish coloration observed in mulberry leaves and also offer supporting evidence for the hypothesis that anthocyanins serve a protective function in plant tissues until the processes of light absorption and carbon fixation reach maturity, thereby ensuring a balanced equilibrium between energy capture and utilization.

Anthocyanins-natural pigment of colored rice bran: Composition and biological activities

Rice by-products are a potential source of various bioactive substances with great processing potential, which are receiving increasing attention. Among them, rice bran is a by-product of rice milling, with high nutritional value and health benefits. Colored rice bran contains a large amount of anthocyanins responsible for color and bioactivities. And anthocyanins are often added to foods as a natural pigment, serving to enhance both the visual appeal and nutritional value. Recent advances in the composition and bioactivities of four common colored rice bran anthocyanins (black, purple, red, and purple red rice) are reviewed in this paper. Rice bran anthocyanins have been confirmed to exhibit biological potential for human health, with their main biological activities being antioxidant, anti-atherosclerosis, anti-cancer, neuroprotective, retinoprotective, immunomodulatory, anti-aging and anti-obesity effects. The structure of anthocyanins determines their biological activities. The anthocyanins composition of rice bran with different colors varied greatly, while that of rice bran with the same color is also slightly different, which is attributed to the rice varieties, growing environment and cropping conditions. However, it remains necessary to conduct further clinical studies to support the health activities of anthocyanins. The present review provides information value for the further development and comprehensive utilization of rice bran anthocyanins.

Gamma Irradiation Promotes the Growth Rate of Thai Pigmented Rice As Well As Inducing the Accumulation of Bioactive Compounds and Carbohydrate Hydrolyzing Enzymes Inhibitors (α-Glucosidase and α-Amylase) under Salt Conditions

Rice contains many bioactive compounds that perform various biological activities. Some of these compounds have been identified as α-glucosidase and α-amylase inhibitors, including guaiacol, vanillin, methyl vanillate, vanillic acid, syringic acid, and 2-pentyl furan. In this study, we assessed the growth rate, photosynthetic pigment content, phenolic content, and flavonoid content of gamma-irradiated Thai pigmented rice. Bioactive components of gamma-irradiated rice that had been subjected to salt treatment were also investigated. The findings showed that production of photosynthetic pigments, which are associated with plant growth, was induced by low gamma exposure. Phenolic and flavonoid content of rice was increased after gamma irradiation at 5 to 1,000 Gy. Both gamma irradiation and the salt conditions changed the quantity of vanillin, methyl vanillate, and vanillic acid in the rice. However, at a salt concentration of 40 mM, the salt stress had more of an effect than the gamma dosage. However, the high concentrations of methyl vanillate and vanillic acid detected in the rice under salt conditions were ameliorated by gamma irradiation. Guaiacol served as the substrate of guaiacol peroxidase for catalyzed reactive oxygen species, as evidenced by the observation that the guaiacol content of rice decreased between increased gamma dosages. A gamma dose of 40 to 1,000 Gy resulted in the production of syringic acid. Under salt stress, syringic acid buildup was also seen to be ameliorated by gamma irradiation. In comparison to salt conditions, particularly for 20 mM salt, gamma irradiation had less of an impact on the 2-pentyl furan in rice.

Rice Byproduct Compounds: From Green Extraction to Antioxidant Properties

Currently, rice (Oryza sativa L.) production and consumption is increasing worldwide, and many efforts to decrease the substantial impact of its byproducts are needed. In recent years, the interest in utilizing rice kernels, husk, bran, and germ for the recovery of different molecules, from catalysts (to produce biodiesel) to bioactive compounds, has grown. In fact, rice byproducts are rich in secondary metabolites (phenolic compounds, flavonoids, and tocopherols) with different types of bioactivity, mainly antioxidant, antimicrobial, antidiabetic, and anti-inflammatory, which make them useful as functional ingredients. In this review, we focus our attention on the recovery of antioxidant compounds from rice byproducts by using innovative green techniques that can overcome the limitations of traditional extraction processes, such as their environmental and economic impact. In addition, traditional assays and more innovative methodologies to evaluate the antioxidant activity are discussed. Finally, the possible molecular mechanisms of action of the rice byproduct antioxidant compounds (phenolic acids, flavonoids, γ-oryzanol, and vitamin E) are discussed as well. In the future, it is expected that rice byproduct antioxidants will be important food ingredients that reduce the risk of the development of several human disorders involving oxidative stress, such as metabolic diseases, inflammatory disorders, and cancer.

Microwave and ultrasound-assisted extraction of bioactive compounds from Papaya: A sustainable green process

The demand for sustainable and eco-friendly extraction methods for bioactive compounds from natural sources has increased significantly in recent years. In this study, we investigated the effectiveness of the microwave pretreated ultrasound-assisted extraction (MPUAE) process for the extraction of antioxidants (TPC, DPPH, and FRAP) from papaya pulp and peel. The optimized variables for the MPUAE process were determined using the Box-Behnken design tool of response surface methodology. Our results showed that the optimized variables for pulp and peel were 675.76 and 669.70 W microwave power, 150 s of irradiation time, 30 °C ultrasound temperature, and 19.70 and 16.46 min of ultrasonic extraction time, respectively. Moreover, the MPUAE process was found to be more energy-efficient and environmentally friendly compared to the conventional ultrasound-associated extraction (UAE) technique. The MPUAE process emitted less CO2 to the environment and had a shorter extraction time, resulting in a more sustainable and cost-effective extraction process. Our study suggests that the MPUAE process has the potential to be a promising and eco-friendly alternative for the industrial extraction of bioactive compounds from papaya and other natural sources.

Stabilization of Rice Bran: A Review

One of the major problems in food science is meeting the demand of the world's growing population, despite environmental limitations such as climate change, water scarcity, land degradation, marine pollution, and desertification. Preventing food from going to waste and utilizing nutritive by-products as food rather than feed are easy and powerful strategies for overcoming this problem. Rice is an important staple food crop for more than half of the world's population and substantial quantities of rice bran emerge as the main by-product of rice grain milling. Usually, rice bran is used as animal feed or discarded as waste. Although it is highly nutritious and comprises many bioactive compounds with considerable health benefits, the rapid deterioration of bran limits the exploitation of the full potential of rice bran. Hydrolytic rancidity is the main obstacle to using rice bran as food, and the enzyme inactivation process, which is termed stabilization, is the only way to prevent it. This study reviews the methods of stabilizing rice bran and other rice-milling by-products comprising rice bran in the context of the efficiency of the process upon storage. The effect of the process on the components of rice bran is also discussed.

Extraction of phenolic compounds from rice husk via ethanol-water-modified supercritical carbon dioxide

Rice husk, a rice processing byproduct generated in large quantities (∼20% of the grain weight), creates a major disposal problem for the rice industry. However, rice husk contains high-value bioactive compounds that can provide potential health benefits. The objective of this study was to extract high-value phenolic compounds from rice husk using supercritical carbon dioxide (SC-CO₂) technology. In this study, the effects of different extraction conditions, namely, temperature (40 and 60 °C), pressure (30 and 40 MPa), and ethanol concentration (15 and 25%, w/w) on the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (AA) were investigated. The extraction of phenolic compounds was also studied using different SC-CO₂ modifiers, i.e., ethanol and ethanol-water. The highest TPC, TFC, and AA were achieved with 30 MPa, 60 °C, and 25% ethanol-water (50%, v/v) cosolvent mixture as 1.29 mg gallic acid equivalent (GAE)/g, 0.40 mg catechin equivalent (CE)/g, and 0.23 mg Trolox equivalent (TE)/g, respectively. Increasing water content up to 50% (v/v) in the cosolvent significantly improved the extraction yield. p-Coumaric, ferulic, and syringic acids were the predominant phenolic acids in the extracts obtained by cosolvent-modified SC-CO₂ and methanol extractions. In addition, ethanol-water-modified SC-CO₂ increased rice husk's porosity, which could be a potential pretreatment to enhance cellulose extraction. Thus, ethanol-water-modified SC-CO₂ can be utilized to recover polar bioactive compounds from food processing byproducts for developing functional foods while eliminating the use of toxic organic solvents.

Valorization of Rice Husk (Oryza sativa L.) as a Source of In Vitro Antiglycative and Antioxidant Agents

Rice husk is a good source of polyphenols, but it has not been efficiently utilized in food applications yet. Therefore, the aim of this work is to investigate, by in vitro assays, the polyphenolic extract (RHE) capacity of this waste to counteract the protein glycation at different stages of the reaction, correlating this activity with the antiradical properties. A microwave-assisted extraction using hydro-alcoholic solvents was applied to recover husk polyphenols. Extraction parameters were optimized by the design of the experiment. The extract with the highest polyphenolic recovery was obtained at 500 W and 90 °C, using 1:35 g of dry material/mL solvent, 80% ethanol, and a 5 min extraction time. Results highlight the ability of RHE to inhibit the formation of fructosamine in the early stage of glycation with a dose-dependent activity. Furthermore, in the middle stage of the reaction, the highest RHE tested concentration (2.5 mg/mL) almost completely inhibit the monitored advanced glycation end products (AGEs), as well as showing a good trapping ability against α-dicarbonyl intermediates. A strong positive correlation with antioxidant activity is also found. The obtained results are supported by the presence of ten polyphenols detected by RP-HPLC-DAD-ESI-MSⁿ, mainly hydroxycinnamic acids and flavonoids, already reported in the literature as antiglycative and antioxidant agents.

Variation of Anthocyanin, Phenol, and Antioxidant Capacity in Straw among Rice Varieties and Growing Locations as a Potential Source of Natural Bioactive Compounds

This study evaluated the variation in bioactive compounds (anthocyanins, phenols, and antioxidants) among 22 rice varieties in the same growing locations and among four varieties collected from eight different provinces in Northern Thailand. Wide variation in anthocyanins, phenols, and antioxidant capacity was established, ranging from 1.6 to 33.0 mg/100 g, 249.9 to 477.7 mg gallic acid/100 g, and 0 to 3,288.5 mg trolox equivalent/100 g, respectively. The highest straw anthocyanin and phenol concentrations were found in KDK (a traditional photoperiod-sensitive variety with purple pericarp and leaves) and K4 (an advanced, photoperiod-insensitive variety with purple pericarp and leaves), while the highest antioxidant capacity was found in KH CMU (an improved traditional photoperiod sensitive variety with a purple pericarp and green leaves) and K4. The variation of the bioactive compounds was also found in the same variety grown at different locations, e.g., the KDMl105 grown in Prayao province had a straw anthocyanin concentration higher than when grown in Mae Hong Son province. The effect was also observed in phenol content and antioxidant capacity when the same rice variety was grown across various locations. A significant correlation between total phenol and antioxidant capacity was observed across rice varieties and growing locations but was not found between anthocyanin and antioxidant capacity. This study found that the bioactive compounds in rice straw varied among rice varieties and growing locations. Straw phenol acts as a major antioxidant that can be used as a characteristic for the selection of rice varieties with high antioxidant capacity for use at the industrial scale for the processing of food, pharmaceuticals, and medicinal products.

Effect of novel combination processing technologies on extraction and quality of rice bran oil

Rice bran, a primary by-product from the rice processing industries, containing 10-15% oil, attracts significant attention from consumers due to its many health-promoting effects. The extraction methodology used is one of the most critical factors affecting the quality and yield of oil from rice bran. Using solvents is the current commercial process for rice bran oil extraction, which has its setbacks. It is challenging and expensive, and there is a risk of traces of solvent residue in the oil. Emerging combination extraction technologies offer zero to minimal solvent residues or chemical deformation while considering increasing environmental and energy footprint. Emerging combination processing technologies include new-age methods like supercritical fluid extraction, sub-critical fluid extraction, ultrasound-assisted enzymatic extraction, ohmic heating, and microwave-assisted extraction. These techniques have been reported to extract oil from rice bran, improving extraction efficiency and quality. These techniques demonstrate solid prospects for future applications. The present review discusses and compares these emerging technologies for oil extraction from rice bran commercially.

Metabolomics for Agricultural Waste Valorization: Shifting Toward a Sustainable Bioeconomy

Agriculture has been considered as a fundamental industry for human survival since ancient times. Local and traditional agriculture are based on circular sustainability models, which produce practically no waste. However, owing to population growth and current market demands, modern agriculture is based on linear and large-scale production systems, generating tons of organic agricultural waste (OAW), such as rejected or inedible plant tissues (shells, peels, stalks, etc.). Generally, this waste accumulates in landfills and creates negative environmental impacts. The plant kingdom is rich in metabolic diversity, harboring over 200,000 structurally distinct metabolites that are naturally present in plants. Hence, OAW is considered to be a rich source of bioactive compounds, including phenolic compounds and secondary metabolites that exert a wide range of health benefits. Accordingly, OAW can be used as extraction material for the discovery and recovery of novel functional compounds that can be reinserted into the production system. This approach would alleviate the undesired environmental impacts of OAW accumulation in landfills, while providing added value to food, pharmaceutical, cosmetic, and nutraceutical products and introducing a circular economic model in the modern agricultural industry. In this regard, metabolomics-based approaches have gained increasing interest in the agri-food sector for a variety of applications, including the rediscovery of bioactive compounds, owing to advances in analytical instrumentation and data analytics platforms. This mini review summarizes the major aspects regarding the identification of novel bioactive compounds from agricultural waste, focusing on metabolomics as the main tool.

Microencapsulation of Red Banana Peel Extract and Bioaccessibility Assessment by In Vitro Digestion

The use of food agricultural wastes as a source of bioactive compounds is an alternative to reduce their environmental impact and generate the possibility of producing value-added products as functional foods. This study aimed to extract and microencapsulate the bioactive compounds from the red banana peel (Musa acuminata Colla AAA “Red”) by spray drying and to evaluate the bioaccessibility of the bioactive compounds by in vitro digestion. The microencapsulation of bioactive compounds was carried out using two wall materials gum arabic (GA) and soy protein isolate (SPI). Microencapsulation using GA and SPI proved to be an effective technique to protect the phenolic compounds, flavonoids and antioxidant capacity of banana peel extract under in vitro digestion conditions. The extract without the encapsulation process suffered a significant (p ≤ 0.05) decrease in bioactive compounds and antioxidant capacity after in vitro digestion. Although microcapsules with SPI held the bioactive compounds for longer in the matrix, no significant difference (p ≤ 0.05) in bioactive compounds retention after in vitro digestion was observed between the microcapsules with GA or SPI. These results indicate that the microcapsules obtained may be used in the food industry as potential ingredients for developing functional foods to promote health benefits.

Prevention of Enzymatic Browning by Natural Extracts and Genome-Editing: A Review on Recent Progress

Fresh fruits and vegetable products are easily perishable during postharvest handling due to enzymatic browning reactions. This phenomenon has contributed to a significant loss of food quality and appearance. Thus, a safe and effective alternative method from natural sources is needed to tackle enzymatic browning prevention. The capabilities of natural anti-browning agents derived from plant- and animal-based resources in inhibiting enzymatic activity have been demonstrated in the literature. Some also possess strong antioxidants properties. This review aims to summarize a recent investigation regarding the use of natural anti-browning extracts from different sources for controlling the browning. The potential applications of genome-editing in preventing browning activity and improving postharvest quality is also discussed. Moreover, the patents on the anti-browning extract from natural sources is also presented in this review. The information reviewed here could provide new insights, contributing to the development of natural anti-browning extracts and genome-editing techniques for the prevention of food browning.

Development of a paddy-based biorefinery approach toward improvement of biomass utilization for more bioproducts

Improvement of biomass utilization productivity following cascading strategy is a priority for the biorefinery-based circular bioeconomy. In recent years, the field of energy research has seen an increasing interest in bio-products from paddy-based biorefinery, but the utilization of the entire value of paddy biomass to guide the commercial viability of its products has not been got feasible outcomes. Here we propose a potential pathway for a conceptual paddy biorefinery framework by addressing wastes for producing more products. The feasibility of the integrated biorefinery was demonstrated by the conversion of wastes into value-added products such as nano-silica and lignin. In particular, this is the first time that silica recovered from bioethanol system was continued to be reused to produce ZSM-5 and Ni/ZSM-5 as catalysts of rice straw lignin depolymerization achieving high conversion of lignin up to 95% and fair yield of phenolic products up to 41%. Material flow of an integrated biorefinery model was reported to give a future outlook for making most of the processing routes of rice residues. We also established a life cycle that follows the circular bioeconomy concept and discussed the relationship between each of potential bioproducts and their market opportunities.

Antioxidation, Anti-Inflammation, and Regulation of SRD5A Gene Expression of Oryza sativa cv. Bue Bang 3 CMU Husk and Bran Extracts as Androgenetic Alopecia Molecular Treatment Substances

Androgenetic alopecia (AGA), a hair loss disorder, is a genetic predisposition to sensitive androgens, inflammation, and oxidative stress. Unfortunately, current treatments with synthetic medicines contain a restricted mechanism along with side effects, whereas the bioactive constituents of plant extracts are multifunctional, with fewer side effects. The massive amounts of rice husk and bran are agricultural wastes that may cause pollution and environmental problems. Owing to these rationales, the local rice variety, Bue Bang 3 CMU (BB3CMU), which is grown in northern Thailand, was evaluated for the valuable utilization of rice by-products, husk (BB3CMU-H) and bran (BB3CMU-RB) extracts, for AGA treatment regarding antioxidant, anti-inflammatory, anti-androgenic activities, and the characterization of bioactive compounds. Our study verified that BB3CMU-H had the highest level of polyphenols, contributing to its greater antioxidant activity. Conversely, BB3CMU-RB was the predominant source of tocopherols, resulting in better anti-androgenic activities regarding the downregulation of steroid 5α-reductase genes (SRD5A). Notably, anti-inflammation via the attenuation of nitric oxide productions was observed in BB3CMU-H (0.06 ± 0.13 μM) and BB3CMU-RB (0.13 ± 0.01 μM), which were significantly comparable to diclofenac sodium salt (0.13 ± 0.19 μM). Therefore, the combination of BB3CMU-H and BB3CMU-RB could be utilized in cosmeceutical and pharmaceutical applications for AGA patients.

Value-Added Metabolites from Agricultural Waste and Application of Green Extraction Techniques

The agricultural sector generates approximately 1300 million tonnes of waste annually, where up to 50% comprising of raw material are discarded without treatment. Economic development and rising living standards have increased the quantity and complexity of waste generated resulting in environmental, health and economic issues. This calls for a greener waste management system such as valorization or recovery of waste into products. For successful implementation, social acceptance is an essential component with involvement of all local stakeholders including community to learn and understand the process and objective of the implementation. The agricultural waste product manufacturing industry is expected to increase with the growing demand for organic food. Thus, proper livestock and crop waste management is vital for environmental protection. It will be essential to successfully convert waste into a sustainable product that is reusable and circulated in the system in line with the green concept of circular economy. This review identifies the commercially produced crops by-product that have been considered for valorization and implemented green extraction for recovery. We highlight the importance of social acceptance and the economic value to agricultural waste recycling. Successful implementation of these technologies will overcome current waste management problems, reduce environmental impacts of landfills, and sustainability issue for farm owners.

Valorization of Rice Straw into Cellulose Microfibers for the Reinforcement of Thermoplastic Corn Starch Films

In the present study, agro-food waste derived rice straw (RS) was valorized into cellulose microfibers (CMFs) using a green process of combined ultrasound and heating treatments and were thereafter used to improve the physical properties of thermoplastic starch films (TPS). Mechanical defibrillation of the fibers gave rise to CMFs with cumulative frequencies of length and diameters below 200 and 5–15 µm, respectively. The resultant CMFs were successfully incorporated at, 1, 3, and 5 wt% into TPS by melt mixing and also starch was subjected to dry heating (DH) modification to yield TPS modified by dry heating (TPSDH). The resultant materials were finally shaped into films by thermo-compression and characterized. It was observed that both DH modification and fiber incorporation at 3 and 5 wt% loadings interfered with the starch gelatinization, leading to non-gelatinized starch granules in the biopolymer matrix. Thermo-compressed films prepared with both types of starches and reinforced with 3 wt% CMFs were more rigid (percentage increases of ~215% for TPS and ~207% for the TPSDH), more resistant to break (~100% for TPS and ~60% for TPSDH), but also less extensible (~53% for TPS and ~78% for TPSDH). The incorporation of CMFs into the TPS matrix at the highest contents also promoted a decrease in water vapor (~15%) and oxygen permeabilities (~30%). Finally, all the TPS composite films showed low changes in terms of optical properties and equilibrium moisture, being less soluble in water than the TPSDH films.

The Potential of Selected Agri-Food Loss and Waste to Contribute to a Circular Economy: Applications in the Food, Cosmetic and Pharmaceutical Industries

The food sector includes several large industries such as canned food, pasta, flour, frozen products, and beverages. Those industries transform agricultural raw materials into added-value products. The fruit and vegetable industry is the largest and fastest-growing segment of the world agricultural production market, which commercialize various products such as juices, jams, and dehydrated products, followed by the cereal industry products such as chocolate, beer, and vegetable oils are produced. Similarly, the root and tuber industry produces flours and starches essential for the daily diet due to their high carbohydrate content. However, the processing of these foods generates a large amount of waste several times improperly disposed of in landfills. Due to the increase in the world’s population, the indiscriminate use of natural resources generates waste and food supply limitations due to the scarcity of resources, increasing hunger worldwide. The circular economy offers various tools for raising awareness for the recovery of waste, one of the best alternatives to mitigate the excessive consumption of raw materials and reduce waste. The loss and waste of food as a raw material offers bioactive compounds, enzymes, and nutrients that add value to the food cosmetic and pharmaceutical industries. This paper systematically reviewed literature with different food loss and waste by-products as animal feed, cosmetic, and pharmaceutical products that strongly contribute to the paradigm shift to a circular economy. Additionally, this review compiles studies related to the integral recovery of by-products from the processing of fruits, vegetables, tubers, cereals, and legumes from the food industry, with the potential in SARS-CoV-2 disease and bacterial diseases treatment.

Graphene Oxide Increases Corneal Permeation of Ciprofloxacin Hydrochloride from Oleogels: A Study with Cocoa Butter-Based Oleogels

In this work, oleogels of cocoa butter (CB), rice bran oil (RBO), and graphene oxide (GO) were prepared. The prepared oleogels were subjected to various characterization techniques such as bright-field microscopy, X-ray diffraction (XRD), crystallization kinetics, differential scanning calorimetry (DSC), and mechanical studies. The influence of increasing GO content on the in vitro drug release and ex vivo corneal permeation of the model drug (ciprofloxacin HCl-CPH) from the oleogels was also investigated. Bright-field micrographs showed that increment in GO content reduced the size of the globular particles of CB. XRD analysis revealed that CB was crystallized in its β' and β polymorphic forms in the oleogels, which was in agreement with thermal studies. The mechanical characterization demonstrated that the presence of GO improved the elastic nature and stress-bearing properties of the oleogels. Moreover, GO altered the crystallization kinetics of CB in the oleogels in a composition-dependent manner. The in vitro release of CPH from the oleogels occurred through either Fickian diffusion or fat network relaxation or a combination thereof. Furthermore, the inclusion of GO enhanced the ex vivo permeation of CPH molecules across the caprine cornea. Hence, we concluded that the prepared oleogels could be explored as potential delivery systems for ophthalmic applications.

Application of Ultrasound Pre-Treatment for Enhancing Extraction of Bioactive Compounds from Rice Straw

The extraction of water-soluble bioactive compounds using different green methods is an eco-friendly alternative for valorizing agricultural wastes such as rice straw (RS). In this study, aqueous extracts of RS (particles < 500 µm) were obtained using ultrasound (US), reflux heating (HT), stirring (ST) and a combination of US and ST (USST) or HT (USHT). The extraction kinetics was well fitted to a pseudo-second order model. As regards phenolic compound yield, the US method (342 mg gallic acid (GAE). 100 g-1 RS) was more effective than the ST treatment (256 mg GAE.100 g-1 RS), reaching an asymptotic value after 30 min of process. When combined with HT (USHT), the US pre-treatment led to the highest extraction of phenolic compounds from RS (486 mg GAE.100 g-1 RS) while the extract exhibited the greatest antioxidant activity. Furthermore, the USHT extract reduced the initial counts of Listeria innocua by 1.7 logarithmic cycles. Therefore, the thermal aqueous extraction of RS applying the 30 min US pre-treatment, represents a green and efficient approach to obtain bioactive extracts for food applications.

An overview on antioxidant peptides from rice bran proteins: extraction, identification, and applications

Rice by-products, generated through the milling processes, have recently been recognized as a potential source of bioactive compounds, such as proteins, essential amino acids, and phenolics. Owing to their antioxidant capacity (which improve the storage stability of foods), these compounds have gained much attention because of their beneficial impacts on human health. It has to be noted that large quantities of rice by-products are not efficiently utilized, which may result in industrial wastes and environmental consequences. Thence, the aim of this review is to provide a comprehensive insight on the antioxidant capabilities, extraction, identification, functional attributes, and applications of bioactive hydrolysates and peptides derived from rice bran protein. This overview would provide an insight on rice bran proteins, which are abundant in bioactive peptides, and could be used as value-added products in food and pharmaceutical applications. Inclusion of bioactive peptides to prevent food spoilage while maintaining food safety has also been highlighted.

Fate of Residual Pesticides in Fruit and Vegetable Waste (FVW) Processing

Plants need to be protected against pests and diseases, so as to assure an adequate production, and therefore to contribute to food security. However, some of the used pesticides are harmful compounds, and thus the right balance between the need to increase food production with the need to ensure the safety of people, food and the environment must be struck. In particular, when dealing with fruit and vegetable wastes, their content in agrochemicals should be monitored, especially in peel and skins, and eventually minimized before or during further processing to separate or concentrate bioactive compounds from it. The general objective of this review is to investigate initial levels of pesticide residues and their potential reduction through further processing for some of the most contaminated fruit and vegetable wastes. Focus will be placed on extraction and drying processes being amid the main processing steps used in the recuperation of bioactive compounds from fruit and vegetable wastes.

Microencapsulation of Rambutan Peel Extract by Spray Drying

Microencapsulation of bioactive compounds (BC) from rambutan peel by spray drying using DE10 maltodextrin as encapsulating agent was performed. The optimal conditions for the ethanolic extraction of BC were 60 °C, with a time of 1 h, 55% aqueous ethanol and three extraction cycles. The best spray drying encapsulating conditions for BC and antioxidant capacity (AC) were: inlet temperature 160 °C, outlet temperature 80 °C, and 10% encapsulating agent concentration in the feeding solution (core:encapsulating agent ratio of 1:4). With these conditions, retention and encapsulation efficiencies obtained were higher than 85%, the water activity value, moisture content and Hausner Index were of 0.25 ± 0.01, 3.95 ± 0.10%, and 1.42 ± 0.00, respectively. The optimized powder presented good solubility and morphological properties, showing microcapsules without ruptures. Based on these results, microencapsulation by spray drying is a viable technique which protects BC of rambutan peel, facilitating its application in the food, pharmaceutical, and cosmetic industries.

Transformation of rice bran into single-cell protein, extracted protein, soluble and insoluble dietary fiber, and minerals

BACKGROUND

It is evident that, during the conversion of agricultural sidestreams into valuable substances, a complete utilization is necessary for economic reasons. The present study investigated the transformation of defatted rice bran into proteins (single cell and extracted protein), soluble and insoluble dietary fiber, and minerals.

RESULTS

In a process chain, starch/glucose was enzymatically extracted and converted into single cell protein (Chlorella sorokiniana). Then, rice bran proteins were extracted and partially precipitated. The remaining liquid was ultrafiltered (3 kDa) to obtain a further protein fraction and minerals. The protein fraction contained a considerable amount of soluble dietary fiber. With these steps, around 69% of the rice bran was transformed, resulting in three protein fractions with an average purity of approximately 45% and minerals with a purity of approximately 63%. In a subsequent process, the remaining cake was disintegrated at 95 °C and pH 2. A further 12% of the rice bran could be liquefied. After centrifugation, the supernatant was subjected to ultrafiltration (3 kDa) to obtain soluble dietary fiber in the retentate and minerals in the permeate. However, only around 2% of the rice bran was converted into soluble dietary fiber, whereas the remainder comprised a mixture of minerals and monomeric sugars.

CONCLUSION

The process chain can be rearranged and optimized especially to increase the output of soluble dietary fiber and proteins as a result of using the digested monomeric sugars for algae cultivation. At the end of the process, 18% of rice bran remained as an insoluble dietary fiber fraction. © 2019 Society of Chemical Industry.