Valorization of rice by-products: Protein-phenolic based fractions with bioactive potential

Comparative assessment of emissions, performance, and economics parameters for a dual-fuel diesel generator operating with rice bran biodiesel and hydrogen

The first step to achieving an energy transition is partially substituting fossil fuels with other more environmentally friendly alternatives, such as hydrogen gas. The current research aims to evaluate the influence of hydrogen in a diesel generator fueled with rice bran biodiesel. The above encourages the use of hydrogen and biodiesel production from residual raw material. For the development of the research, a diesel engine bench was used, which operated in five load conditions: 20 %, 40 %, 60 %, 80 %, and 100 %, and was fed with three fuels: -100 %, RB-10 %, and RB-10 % + H2(30 %). The results show that the mixture RB-10 % + H2(30 %) causes a 3.14 % reduction in BSFC and a 3.26 % increase in energy conversion efficiency. In addition, it is observed that a 9.90 %, 12.57 %, and 10.99 % decrease in HC, CO, and smoke opacity emissions compared to pure diesel. On the other hand, the mixture RB-10 % + H2(30 %) reduces by 4.44 %, 5.07 %, and 7.06 % the environmental, social, and ecological impact due to CO2, HC, and CO emissions, as well as a 3.93 % reduction in engine operating cost compared to RB-10 % biodiesel. In general, hydrogen injection is a promising alternative to promote the use of rice bran biodiesel due to its increased performance characteristics and reduced pollutant emissions without the need to modify the engine.

Functional and Bioactive Properties of Wheat Protein Fractions: Impact of Digestive Enzymes on Antioxidant, α-Amylase, and Angiotensin-Converting Enzyme Inhibition Potential

This research aimed to determine the biofunctional properties of wheat flour (WF) protein fractions and modifications to the antioxidant, anti-α-amylase and anti-angiotensin-I converting enzyme (ACE) activities induced by the action of digestive endopeptidases in vitro. A molecular characterization of the most abundant protein fractions, i.e., albumins, glutelins-1, glutelins-2 and prolamins, showed that low- and high-MW polypeptides rich in cysteine, glutamic acid and leucine were present in albumins and glutelins, whereas low-MW subunits with a high proportion of polar amino acids prevailed in prolamins. Prolamins exhibited the second-highest water holding capacity (54%) after WF (84%), while albumins provided superior foam stability (76%). Prolamins, glutenins-1 and globulins demonstrated the highest antioxidant activity (up to 95%, 68% and 59%, respectively) both before and after hydrolysis with pepsin (P-H) or trypsin-chymotrypsin (TC-H). Prolamins, globulins and WF strongly inhibited α-amylase (>90%) before and after TC-H, and before P-H (55-71%). Moreover, P-H significantly increased α-amylase inhibition by albumins from 53 to 74%. The fractions with strong ACE inhibitory activity (70-89%) included prolamins and globulins after TC-H or P-H, as well as globulins before TC-H and WF before P-H. This novel evidence indicates that WF protein fractions and their peptide-enriched P and TC hydrolysates are excellent sources of multifunctional bioactives with antioxidant, antihyperglycemic and antihypertensive potential.

A review of the structure, function, and application of plant-based protein-phenolic conjugates and complexes

Interactions between plant-based proteins (PP) and phenolic compounds (PC) occur naturally in many food products. Recently, special attention has been paid to the fabrication of PP-PC conjugates or complexes in model systems with a focus on their effects on their structure, functionality, and health benefits. Conjugates are held together by covalent bonds, whereas complexes are held together by noncovalent ones. This review highlights the nature of protein-phenolic interactions involving PP. The interactions of these PC with the PP in model systems are discussed, as well as their impact on the structural, functional, and health-promoting properties of PP. The PP in conjugates and complexes tend to be more unfolded than in their native state, which often improves their functional attributes. PP-PC conjugates and complexes often exhibit improved in vitro digestibility, antioxidant activity, and potential allergy-reducing activities. Consequently, they may be used as antioxidant emulsifiers, edible film additives, nanoparticles, and hydrogels in the food industry. However, studies focusing on the application of PP-PC conjugates and complexes in real foods are still scarce. Further research is therefore required to determine the structure-function relationships of PP-PC conjugates and complexes that may influence their application as functional ingredients in the food industry.

Investigation of the Effect of Rice Bran Content on the Antioxidant Capacity and Related Molecular Conformations of Plant-Based Simulated Meat Based on Raman Spectroscopy

At present, plant-based simulated meat is attracting more and more attention as a meat substitute. This study discusses the possibility of partial substitution of rice bran (RB) for soybean protein isolate (SPI) in preparing plant-based simulated meat. RB was added to SPI at 0%, 5%, 10%, 15%, and 20% to prepare RB-SPI plant-based simulated meat by the high moisture extrusion technique. RB-SPI plant-based simulated meat revealed greater polyphenol content and preferable antioxidant capacity (DPPH radical scavenging capacity, ABTS scavenging ability, and FRAP antioxidant capacity) compared to SPI plant-based simulated meat. The aromatic amino acids (tryptophan and tyrosine) of RB-SPI plant-based simulated meats tend to be masked first, and then the hydrophobic groups are exposed as RB content increases and the polarity of the surrounding environment increases due to the change in the disulfide conformation of RB-SPI plant-based simulated meats from a stable gauche-gauche-gauche conformation to a trans-gauche-trans conformation.

An Update Regarding the Bioactive Compound of Cereal By-Products: Health Benefits and Potential Applications

Cereal processing generates around 12.9% of all food waste globally. Wheat bran, wheat germ, rice bran, rice germ, corn germ, corn bran, barley bran, and brewery spent grain are just a few examples of wastes that may be exploited to recover bioactive compounds. As a result, a long-term strategy for developing novel food products and ingredients is encouraged. High-value compounds like proteins, essential amino acids, essential fatty acids, ferulic acid, and other phenols, tocopherols, or β-glucans are found in cereal by-products. This review aims to provide a critical and comprehensive overview of current knowledge regarding the bioactive compounds recovered from cereal by-products, emphasizing their functional values and potential human health benefits.

Cereal Waste Valorization through Conventional and Current Extraction Techniques-An Up-to-Date Overview

Nowadays, in the European Union more than 100 million tons of food are wasted, meanwhile, millions of people are starving. Food waste represents a serious and ever-growing issue which has gained researchers’ attention due to its economic, environmental, social, and ethical implications. The Sustainable Development Goal has as its main objective the reduction of food waste through several approaches such as the re-use of agro-industrial by-products and their exploitation through complete valorization of their bioactive compounds. The extraction of the bioactive compounds through conventional methods has been used for a long time, whilst the increasing demand and evolution for using more sustainable extraction techniques has led to the development of new, ecologically friendly, and high-efficiency technologies. Enzymatic and ultrasound-assisted extractions, microwave-assisted extraction, membrane fractionation, and pressure-based extraction techniques (supercritical fluid extraction, subcritical water extraction, and steam explosion) are the main debated green technologies in the present paper. This review aims to provide a critical and comprehensive overview of the well-known conventional extraction methods and the advanced novel treatments and extraction techniques applied to release the bioactive compounds from cereal waste and by-products.