Increasing demand for fuels and chemicals, driven by factors including over-population, the threat of global warming and the scarcity of fossil resources, strains our resource system and necessitates the development of sustainable and innovative strategies for the chemical industry. Our society is currently experiencing constraints imposed by our resource system, which drives industry to increase its overall efficiency by improving existing processes or finding new uses for waste. Food supply chain waste emerged as a resource with a significant potential to be employed as a raw material for the production of fuels and chemicals given the abundant volumes globally generated, its contained diversity of functionalised chemical components and the opportunity to be utilised for higher value applications. The present manuscript is aimed to provide a general overview of the current and most innovative uses of food supply chain waste, providing a range of worldwide case-studies from around the globe. These studies will focus on examples illustrating the use of citrus peel, waste cooking oil and cashew shell nut liquid in countries such as China, the UK, Tanzania, Spain, Greece or Morocco. This work emphasises 2nd generation food waste valorisation and re-use strategies for the production of higher value and marketable products rather than conventional food waste processing (incineration for energy recovery, feed or composting) while highlighting issues linked to the use of food waste as a sustainable raw material. The influence of food regulations on food supply chain waste valorisation will also be addressed as well as our society's behavior towards food supply chain waste. “There was no ways of dealing with it that have not been known for thousands of years. These ways are essentially four: dumping it, burning it, converting it into something that can be used again, and minimizing the volume of material goods – future garbage – that is produced in the first place.” William Rathje on waste (1945–2012) – Director of the Tucson Garbage project.

Food waste as a valuable resource for the production of chemicals, materials and fuels. Current situation and global perspective

A comprehensive review of the literature about use of solvents for extraction of oilseeds is presented. Mention has been found of over 70 solvents. Currently, hexane is the major solvent in use, but recent price increases and safety, environmental and health concerns, have generated interest in alternatives. Solvents vary considerably in chemical and physical properties which affect their performance in oil extraction. The choice of solvent depends upon the primary end product desired (oil or meal). Recent research on alternative solvents has focused on ethanol, isopropanol, methylene chloride, aqueous acetone, and hexane/acetone/water mixtures.

Comparison of alternative solvents for oils extraction

Glandless cottonseed: A review of the first 25 years of processing and utilization research

Gossypol (C 30 H 30 O 8 ) is a polyphenolic compound derived from the cotton plant (genus Gossypium , family Malvaceae). The presence of six phenolic hydroxyl groups and two aldehydic groups makes gossypol chemically reactive. Gossypol can undergo Schiff base formation, ozonolysis, oxidation, and methylation to form gossypol derivatives. Gossypol and its derivatives have been the target of much research due to their multifaceted biological activities including antifertility, antivirus, anticancer, antioxidant, antitrypanosomal, antimicrobial, and antimalarial activities. Because of restricted rotation of the internaphthyl bond, gossypol is a chiral compound, which has two atropisomers (i.e., (+)- and (−)-gossypol) that exhibit different levels of biological activities. This chapter covers the physiochemical properties, analyses, biological properties, and agricultural and clinical implications of gossypol.

Gossypol--a polyphenolic compound from cotton plant.

The residue of cottonseed oil extraction industry popularly known as cottonseed meal (CSM) is a fairly good source of protein (222.0 to 560.2gkg-1) and metabolizable energy (7.4 to 11.99MJkg-1). The use of CSM in poultry diet is limited due to the presence of gossypol, cyclopropenoid fatty acids (CPFA), high fibre and poor protein quality. The most critical amino acid in CSM is lysine. During the oil extraction from cotton- seeds, a portion of free gossypol (FG) binds with the epsilon amino group of lysine, thereby reducing the availability of lysine to the chicken. The concentration of nutrients, FG, CPFA in CSM depends on the variety of cultivars, methods of oil extraction, proportion of kernel to husk, lint and seed coat. The concentration of FG in various varieties of CSM ranges from 200 and 5300mgkg-1. In glandless variety, the FG concentration is less (>130mgkg-1). Gossypol inhibits the activity of pepsin and trypsin in gastro-intestinal tract, thereby reducing the digestibility of protein. The reported toxic effects of gossypol are growth depression, lameness, decreased egg size and hatchability. Gossypol and CPFA also deteriorates the internal egg quality by causing yolk mottling and pinkish discoloration of albumen, respectively. The tolerance levels of FG in birds vary widely depending on the age and strain of birds, protein content and quality, duration of feeding, presence of minerals especially the iron content in the diet. The tolerance of FG in chicks varies widely (90 to 1000mgkg-1 diets), however performance of layer chicks could be affected even at a lower FG intake of 2.02mg day-1 bird-1. Though, growth was not affected in broilers at FG concentration in diet below 150mgkg-1, feed efficiency was reduced at lower levels i.e. 60-100mgkg-1. The depression in egg production in layers fed diets containing more than 100mgkg-1 was mainly due to lowered feed intake. The egg weight and egg quality was not affected at FG levels upto 200mgkg-1 diet. Iron treatment (4 : 1; Fe : FG) proved to be effective in alleviating the negative effects on egg quality, but could not alleviate the depression in laying performance. Lysine supplementation to CSM containing diets is also effective in counteracting the ill effects of FG in chicken, especially chicks and broilers. Other processing methods like solid substrate fermentation, production of glandless cotton seed and use of organic solvents were though effective in improving the nutritive value of CSM and reducing the FG content in CSM, these methods are of little practical relevance and uneconomical. Production of glandless variety of cottonseed through genetic modification (Bacillus thuringiensis cotton) is one of the recent trends of reducing the FG content. Some other methods like pelleting, extrusion, cooking and Ca (OH)2 treatment of CSM could be tried for improving the feeding value of CSM in poultry.

Cottonseed meal in poultry diets: A review

THIS INVENTION RELATES TO A PROCESS FOR EXTRACTING COTTONSEED FLAKES. MORE PARTICULARLY, THIS INVENTION RELATES TO A PROCESS WHEREBY COTTONSEED FLAKES ARE EXTRACTED WITH ACETONE CONTAINING 25-30% WATER TO REMOVE ALL OF THE GOSSYPOL, MOST OF THE FREE FATTY ACIDS, ABOUT HALF OF THE RAFFINOSE, AND NEGLIGIBLE QUANTITIES OF NEUTRAL OIL AND PROTEIN.

Aqueous acetone extraction of cottonseed

Predictions can be made safely that glanded cottonseed is likely to be with us for quite some time. Worldwide, 20 to 22 million metric tons of glanded cottonseed are produced annually. Hence a workable process for the removal of pigment glands is needed urgently if food-grade products are to be made from cottonseed. A brief history of the development of the Liquid Cyclone Process for the preparation of degossypolized cottonseed flour is outlined. Gossypol is removed in pigment glands via liquid cyclones, thus giving the development its name. The process consists of several unique operations including adequate drying of the meats prior to flaking, fluidizing of the flakes using commercial hexane, comminuting the fluidized slurry in a stone mill and adjusting the solids content of the milled slurry for proper separation of the fine flour from the glands, hulls and coarse meal in the cyclones. Finally, the flour is defatted and washed with hexane on a rotary vacuum filter, dried and desolventized under mild conditions to maintain protein quality. It is visualized that the above operations can be incorporated in a satellite plant operated in conjunction with a parent solvent extraction cottonseed oil mill. Sanitary conditions of the satellite plant will meet the exacting standards of the better food processing plants. Raw material specifications as well as type of plant needed and potential markets are discussed.

Degossypolized cottonseed flour—the liquid cyclone process

A process for producing a high protein cottonseed concentrate from cottonseed meats which process is characterized by an integrated sequence of drying, flaking, disintegrating, screen separating and gravity separating steps. The process accomplishes the substantially complete removal of intact cottonseed pigment glands and as a consequence thereof, the isolation of gland-free material, which material can be exalted to exhibit a protein content as high as 73 percent by weight on an oil and moisture free basis.

Process for producing cottonseed protein concentrate

A method has been developed for utilizing low-cost acidulated refinery soapstock directly as raw material for producing the mixed methyl esters of cottonseed oil fatty acids. The conditions determined as optimum for producing the esters were as follows: temperature, 110°C. to 120°C.; pressure, 150 p.s.i.g.; reaction time, 10 to 15 min.; catalyst, acidic, proportioned as 3% to 5% of the fatty acids of the foots; and ratio of reactants, 5 moles of methanol to 1 of fatty acids. Processing acidulated foots containing 12.4% of neutral oil at the foregoing conditions resulted in esterifying 83% to 86% of the fatty acids. Reprocessing the same material after dehydrating it and restoring the initial methanol to fatty acids ratio increased the percentage of fatty acids esterified by about 5%.

Methyl esters directlyfrom acidulated soapstock

Data for the application of the versatile filtration-extraction process to jojoba seed on a bench-scale has been presented. Based on experience with other oil-seeds, there should be good correlation between the bench-scale and its commercial application. Moisture contents of the material during cooking were optimum at 10 and 15%. Mass velocities in excess of 2,000 and extraction efficiencies of over 98% were obtained. These results are considered suitable for commercial application. Hexane is recommended over heptane as the extraction solvent. The use of uncooked flakes is not considered feasible for large-scale application.

P. H. Eaves

Papers

Aqueous acetone extraction of cottonseed

Degossypolized cottonseed flour—the liquid cyclone process

Process for producing cottonseed protein concentrate

Methyl esters directlyfrom acidulated soapstock

Direct extraction of jojoba seed