Cereal Processing By-products Research Articles

Development of Prediction Equations for Digestible and Metabolizable Energy in 15 Cereal Processing By-Products Fed to Growing Pigs

The study was conducted to determine the nutrient digestibility and digestible (DE) and metabolizable energy (ME) of 15 cereal processing by-products and to develop prediction equations for DE and ME based on the chemical composition in growing pigs. A total of 36 crossbred pigs were chosen and divided into three blocks according to a three 12 × 3 Youdin square experimental design. Twelve pigs in each block were allocated into six diets including a basal diet and five test diets. The feeding experiment included three periods, and each dietary treatment contained six replicates. Each period lasted 12 days, including 7 d of dietary adaption and 5 d of total feces and urine collection. The results showed that the coefficients of variation for EE, NDF, ADF, CP, and GE among 15 cereal processing by-products were 86.78%, 49.82%, 51.14%, 14.95%, and 6.26%, respectively. There were significant differences in DE, ME, and ME/DE (DM basis) among 15 cereal processing by-products (p < 0.05), ranging from 11.55 MJ/kg to 17.64 MJ/kg, from 10.90 MJ/kg to 17.40 MJ/kg, and from 89.41% to 98.63%, respectively. The digestibility of GE, DM, NDF, ADF, and CP showed a significant difference among 15 cereal processing by-products (p < 0.05). The DE and ME contents showed a negative correlation to NDF and ADF (p < 0.05), and the prediction equations for DE and ME (as-fed basis) were DE (MJ/kg) = −0.4597 × ADF (%) + 0.5988 × GE (MJ/kg) + 6.0138 (R2 = 0.74; p < 0.05) and ME (MJ/kg) = 1.0440 × DE (MJ/kg) − 1.1235 (R2 = 0.98; p < 0.05). On a DM basis, the optimal prediction equations for DE and ME were DE (MJ/kg DM) = −0.1451 × NDF (%) + 0.3026 × CP (%) + 13.8595 (R2 = 0.72; p < 0.05) and ME (MJ/kg DM) = 1.1155 × DE (MJ/kg DM) + 0.0363 × ADF (%) − 2.3412 (R2 = 0.99; p < 0.05). In conclusion, there were large variations in the chemical composition, nutrients digestibility, and available energy among the 15 different samples of cereal processing by-products. It is reasonable to develop prediction equations for DE and ME based on the chemical composition of cereal by-products for growing pigs.

Derivation of Kokumi γ-Glutamyl Peptides and Volatile Aroma Compounds from Fermented Cereal Processing By-Products for Reducing Bitterness of Plant-Based Ingredients.

Current food production methods and consumption behaviours are unsustainable and contribute to environmental harm. One example is food waste-around 38% of food produced is wasted each year. Here, we show that two common food waste products, wheat bran and brewer's spent grain, can successfully be upcycled via miso fermentation. During the fermentation process, kokumi γ-glutamyl peptides, known to increase mouthfulness, are produced; these include γ-ECG (oxidized), γ-EVG, γ-EV, γ-EE, γ-EF, and γ-EL. The profiles of kokumi peptides and volatile aroma compounds are correlated with koji substrate, pH, and enzymatic activity, offering straightforward parameters that can be manipulated to increase the abundance of kokumi peptides during the fermentation process. Correlation analysis demonstrates that some volatile aroma compounds, such as fatty acid ethyl esters, are correlated with kokumi peptide abundance and may be responsible for fatty, greasy, and buttery aromas. Consumer sensory analysis conveys that the bitter taste of vegetables, such as that in endives, can be dampened when miso extract containing kokumi peptides is added. This suggests that kokumi peptides, along with aroma volatile compounds, can enhance the overall flavour of plant-based products. This study opens new opportunities for cereal processing by-product upcycling via fermentation, ultimately having the potential to promote a plant-based diet.

The Release of Non-Extractable Ferulic Acid from Cereal By-Products by Enzyme-Assisted Hydrolysis for Possible Utilization in Green Synthesis of Silver Nanoparticles.

The present work was undertaken to elucidate the potential contribution of biosynthetically produced ferulic acid (FA) via enzymatic hydrolysis (EH) of rye bran (RB) to the formation of silver nanoparticles (AgNPs) during green synthesis. An analytical approach accomplished by multiple reaction monitoring (MRM) using triple quadrupole mass selective detection (HPLC-ESI-TQ-MS/MS) of the obtained hydrolysate revealed a relative abundance of two isomeric forms of FA, i.e., trans-FA (t-FA) and trans-iso-FA (t-iso-FA). Further analysis utilizing high-performance liquid chromatography with refractive index (HPLC-RID) detection confirmed the effectiveness of RB EH, indicating the presence of cellulose and hemicellulose degradation products in the hydrolysate, i.e., xylose, arabinose, and glucose. The purification process by solid-phase extraction with styrene-divinylbenzene-based reversed-phase sorbent ensured up to 116.02 and 126.21 mg g−1 of t-FA and t-iso-FA in the final eluate fraction, respectively. In the green synthesis of AgNPs using synthetic t-FA, the formation of NPs with an average size of 56.8 nm was confirmed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. The inclusion of polyvinylpyrrolidone (PVP-40) in the composition of NPs during synthesis favorably affected the morphological features, i.e., the size and shape of AgNPs, in which as big as 22.4 nm NPs were engineered. Meanwhile, nearly homogeneous round-shaped AgNPs with an average size of 16.5 nm were engineered using biosynthetically produced a mixture of t-FA and t-iso-FA and PVP-40 as a capping agent. The antimicrobial activity of AgNPs against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa, E. coli, Enterococcus faecalis, Bacillus subtilis, and Staphylococcus aureus was confirmed by the disk diffusion method and additionally supported by values of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Given the need to reduce problems of environmental pollution with cereal processing by-products, this study demonstrated a technological solution of RB rational use in the sustainable production of AgNPs during green synthesis. The AgNPs can be considered as active pharmaceutical ingredients (APIs) to be used for developing new antimicrobial agents and modifying therapies in treating multi-drug resistant (MDR) pathogens.

Sustainable Applications for the Valorization of Cereal Processing By-Products.

This review article revises the sustainable practices and applications to valorize valuable components recovered from cereal processing by-products. After introducing cereal processing by-products, their healthy compounds, and corresponding functional properties, the article explores reutilization opportunities of by-products emphasizing specific sources (e.g., oat and wheat bran, distillers’ dried grains, etc.) and the biorefinery approach. Proteins and soluble dietary fibers such as arabinoxylans are of particular interest due to their content in the cereal processing by-products and their easy extraction based on conventional technologies such as enzyme-assisted extraction and membrane filtration. Non-thermal technologies have also been suggested to improve sustainability recovery approaches. Finally, the article discusses the different applications for the recovered high-added value compounds that span across biotechnology, foods, and bakery products.

Cereal Processing By-Products as Rich Sources of Phenolic Compounds and Their Potential Bioactivities.

In today’s society, we can see a progressive paradigm shift that tends towards a healthy and sustainable lifestyle. The proof is represented by the growing interest in food loss and waste of different sectors, from the political to the academic, or even to the private sector. In order to reduce food waste and to increase sustainability, the European Union (EU) has planned a circular bioeconomy. This action plan includes an approach based on reducing, reusing, recovering, and recycling materials and energy. Every year, there are high amounts of waste and by-products resulting from agricultural producing and agro-industrial processing, impacting the environment and the socio-economic sector. Cereal food products cover over 20% of daily diet, so it can be assumed that cereal production and processing are one of the most important sectors of agri-food industries. It is estimated that the waste generated from cereal processing and manufacturing is up to 13%, a percentage that can be decreased by converting the by-products in raw materials for biofuels, biodegradable plastics, alcohols, antioxidants, food additives, or pharmaceutic ingredients due to their content in macro- and micro-nutrients or bioactive compounds. Based on the fact that diet plays a crucial role in maintaining the integrity of our body, it is important to capitalize on any source of bioactive compounds to which we have access. This review aims to highlight the need to recirculate by-products for the purpose of extraction and use of their key compounds, polyphenols, which have not only antioxidant effects, but also preventive and therapeutic effects against cancer. For these, it is necessary to understand the biotechnologies needed for processing the most consumed cereals, the methods of extraction of phenolic compounds, and the main effects that these compounds have, summarizing the most relevant in vitro and in vivo studies performed so far.

Advances on the Valorisation and Functionalization of By-Products and Wastes from Cereal-Based Processing Industry.

Cereals have been one of the major food resources for human diets and animal feed for thousands of years, and a large quantity of by-products is generated throughout the entire processing food chain, from farm to fork. These by-products mostly consist of the germ and outer layers (bran) derived from dry and wet milling of the grains, of the brewers’ spent grain generated in the brewing industry, or comprise other types obtained from the breadmaking and starch production industries. Cereal processing by-products are an excellent low-cost source of various compounds such as dietary fibres, proteins, carbohydrates and sugars, minerals and antioxidants (such as polyphenols and vitamins), among others. Often, they are downgraded and end up as waste or, in the best case, are used as animal feed or fertilizers. With the increase in world population coupled with the growing awareness about environmental sustainability and healthy life-styles and well-being, the interest of the industry and the global market to provide novel, sustainable and innovative solutions for the management of cereal-based by-products is also growing rapidly. In that respect, these promising materials can be valorised by applying various biotechnological techniques, thus leading to numerous economic and environmental advantages as well as important opportunities towards new product development (NPD) in the food and feed industry and other types such as chemical, packaging, nutraceutical (dietary supplements and food additives), cosmetic and pharmaceutical industries. This review aims at giving a scientific overview of the potential and the latest advances on the valorisation of cereal-based by-products and wastes. We intended it to be a reference document for scientists, technicians and all those chasing new research topics and opportunities to explore cereal-based by-products through a circular economy approach.

Chaff, dung, and wood: fuel use at Tell el-Retaba. Archaeobotanical investigations in the Third Intermediate Period settlement, Area 9 excavations 2015–2019

Results of archaeobotanical investigations from the 2009–2014 excavations of the joint Polish-Slovak-Egyptian mission at the site of Tell el-Retaba have previously been reported in A&L.2 This article provides an update and discussion of results from excavations conducted in 2015, 2016, 2017 and 2019 in Area 9, within the Third Intermediate Period settlement.3 It has been well-established that plant macro-remains are abundant and generally well-preserved at Tell el-Retaba, and they offer a wonderful opportunity to examine changing patterns in the complex relationship between plants and people over at least one thousand years. Analysis of the charred plant archaeobotanical assemblages in the town reveal that wood, sheet/goat dung, and cereal processing byproducts were all used as fuel in households, and that the animals had consumed a sedge-rich diet.

Mechanical profiles and topographical properties of films made from alkaline extracted arabinoxylans from wheat bran, maize bran, or dried distillers grain

Cereal processing byproducts including wheat (Triticum aestivum L.) bran, maize (Zea mays L.) bran, and dried distillers grain are currently utilized in animal feed, but they could be utilized in value-added products such as food packaging materials. This study determined the topographical properties and mechanical profiles of films made from arabinoxylan extracts of wheat bran, maize bran, and dried distillers grain with the addition of either glycerol or sorbitol as a plasticizing agent at one of three levels (10, 25, or 50%). The arabinoxylan was extracted from these starting materials via alkaline extraction and purified using α-amylase, protease, and dialysis. Film properties analyzed included surface topography, puncture resistance, tensile strength, and tear resistance. Topographical analysis showed that the films made with wheat bran arabinoxylan were the roughest. The puncture resistances ranged from 0.7 N (dried distillers grain arabinoxylan films plasticized by 10% sorbitol) to 10.1 N (wheat bran arabinoxylan films plasticized by 50% sorbitol). The highest maximum tensile strength was 29.3 MPa for films made with maize bran arabinoxylan plasticized by 10% glycerol. In addition, these arabinoxylan films had tear resistances ranging from 0.3 N (maize bran arabinoxylan films plasticized by 50% glycerol) to 1.9 N (wheat bran arabinoxylan films plasticized by 50% sorbitol). These material profiles provide information about the strengths and weaknesses of 18 novel materials that could serve as food packaging materials in the future.

Screening of the anthocyanin profile and in vitro pancreatic lipase inhibition by anthocyanin-containing extracts of fruits, vegetables, legumes and cereals.

The phytotherapic treatment of overweight and/or moderate obesity is growing widely, thus there is a great interest towards the phenolic compounds of fruits and vegetables which may inhibit pancreatic lipase enzyme. In this study, we report the chemical composition and in vitro pancreatic lipase inhibitory activity of 13 freeze-dried anthocyanin-containing extracts of different Mediterranean plants: fruits (blood orange, pomegranate, blackberry, mulberry and sumac), citrus by-products (blood orange peel), citrus vegetative tissues (young lemon shoots); vegetables (red cabbage and violet cauliflower), legume seeds (black bean), cereals (black rice), and cereal processing by-products (black rice hull). Total phenols and anthocyanins were determined. Individual anthocyanins were identified by UHPLC-PDA-ESI/MSn . Results revealed a wide variation in the distribution of anthocyanin compounds. Blood orange and pomegranate juice extracts had the highest total anthocyanin content and exhibited the strongest inhibition of pancreatic lipase in vitro. Inhibitory activity was positively correlated with anthocyanin content. In appropriate formulations, anthocyanin-containing extracts could find a use as anti-obesity agents. © 2016 Society of Chemical Industry.

Informal intercropping of legumes with cereals? A re-assessment of clover abundance in ancient Egyptian cereal processing by-product assemblages: archaeobotanical investigations at Khentkawes town, Giza (2300–2100 bc)

The possibility that legumes were specifically cultivated as a separate fodder crop in ancient Egypt has been inferred, usually on the basis of abundance of both legume seeds and or dung in charred macro-botanical samples, combined with a lack of wood charcoal; the implication being that a scarcity of wood led to the use of dung as fuel, and that the legumes in the assemblage derive from livestock which had been fed with cultivated fodder. The archaeobotanical remains from excavations at the Old Kingdom ‘Khentkawes town’ (2300–2100 bc) on the Giza plateau in Egypt contained an abundance of legumes, but also much wood charcoal, and preservation of many fragile and ‘green’ seeds and plant parts. This assemblage has led to questioning of the theory of specific fodder cultivation in Pharaonic Egypt. In this article, alternative interpretations of legume-rich assemblages of cereal processing by-products are investigated. Intercropping of legumes with cereals is one of the most widespread and effective methods of improving crop value and security, and fodder/forage quality. Analysis of this assemblage has led to a hypothesis that Trifolium sp. and other ‘weeds’ may well have been viewed as integral plants within ancient Egyptian cereal fields, due to an awareness of the benefits of intercropping legumes with cereals—as opposed to having been specifically cultivated as a monocrop.

New advances in the integrated management of food processing by-products in Europe: sustainable exploitation of fruit and cereal processing by-products with the production of new food products (NAMASTE EU)

By-products generated every year by the European fruit and cereal processing industry currently exceed several million tons. They are disposed of mainly through landfills and thus are largely unexploited sources of several valuable biobased compounds potentially profitable in the formulation of novel food products. The opportunity to design novel strategies to turn them into added value products and food ingredients via novel and sustainable processes is the main target of recently EC-funded FP7 project NAMASTE-EU. NAMASTE-EU aims at developing new laboratory-scale protocols and processes for the exploitation of citrus processing by-products and wheat bran surpluses via the production of ingredients useful for the formulation of new beverage and food products. Among the main results achieved in the first two years of the project, there are the development and assessment of procedures for the selection, stabilization and the physical/biological treatment of citrus and wheat processing by-products, the obtainment and recovery of some bioactive molecules and ingredients and the development of procedures for assessing the quality of the obtained ingredients and for their exploitation in the preparation of new food products.

New advances on the formulation of new foods and feeds from fruit and cereal processing by-products generated in India and Europe: the joint NAMASTE projects

New advances on the formulation of new foods and feeds from fruit and cereal processing by-products generated in India and Europe: the joint NAMASTE projects