An evaluation of the suitability of selected waste products in feeds for three fish species

Five types of aquatic food industry waste products (carp offal, carp roe, fish frames, trout offal and surimi processing waste) together with fish meal were evaluated for their suitability as potential fish meal replacements, partially or wholly, in diets for three species (rainbow trout, Murray cod and shortfin eel) cultured in Australia, using a number of criteria.

The proximate composition of the ingredients on a dry matter basis including protein content, lipid and ash, varied considerably. The essential amino acid (EAA) contents of the waste products and fish meal decreased in the order: carp roe > fish meal > carp offal > 'surimi' processing waste > fish frames > trout offal. The results of cluster analysis of A/E ratios of waste products and fish whole body fell within three clusters. The EAAI of whole body tissue of Murray cod, rainbow trout and Australian shortfin eel however, were closest to fish meal, followed by fish frame waste and/or 'surimi' waste. The results on A/E ratios and EAAI did not conform to the raw data on TAA and EAA. Therefore, the study emphasizes the need to have a multi-prong approach to determine the suitability of ingredients for incorporation into fish feeds.

'Green' treatment of acid mine drainage - a step towards sustainability

Sustainability is becoming increasingly important in the mining and mineral processing industries and must incorporate the associated waste products. Acid mine drainage (AMD) is one such by-product and is one of the most serious environmental problems facing the minerals industry today. The oxidation of sulphidic mine wastes often continues for a substantial period of time after mine closure, resulting in difficult and costly remediation and rehabilitation works. Mining companies are often reluctant to spend increasing amounts of money on waste treatment when the mine life is limited or even finished. Hence a simple, low maintenance and low-cost method of treating AMD is required. Whilst this paper does not address the issue of AMD, it does propose methods for removal of individual species from AMD with potential benefits, including raising AMD pH.

A novel concept of using biosolids as a biological adsorbent, or ‘biosorbent’, of metals from AMD is being investigated at a laboratory/pilot scale level. Biosolids are a by-product resulting from the biological treatment of wastewater, and have been previously shown to adsorb metals from aqueous solutions. This could lead to an environmentally sustainable or ‘green’ method for treating both AMD discharges and disposing/reusing the biosolids.

The result of a laboratory-scale study of the biosorption of Zn(II) is presented in this paper. Physical parameters including reaction kinetics, mixing speed and solution pH were investigated. Solution pH also rose an average of 2 pH units over the 24 hour equilibrium time – a valuable side effect when treating acid mine drainage. The outcome of the study highlights the usefulness of biosolids as a biosorbent for the removal/recovery of metal ions from acid mine drainage. A simple, low-cost treatment technology requiring low maintenance would be beneficial to the mining industry to address some issues relating to AMD and would help integrate environmental and economic considerations into sustainable environmental management.

In situ stabilisation of pavements using cementitious binders

An extensive study was made of the physical properties of a range of cementitiously stabilised materials to determine their suitability for use in in situ pavement construction. This process for recycling existing pavements has considerable environmental and cost benefits. Pavement models incorporating these materials were analysed to determine their structural behaviour.

Mothering siblings: Diaspora, desire and identity in American born confused Desi

In this essay we consider the construction of cultural identity, motherhood and the family in ABCD, a film of the Indian diaspora that had its world premiere at the 2001 London Film Festival. This film reads family, apparently within familiar narrative structures such as the U.S.-immigrant story, as portrayed in films like Goodbye, Columbus and My Big Fat Greek Wedding, and the "leaving home" story, as classically portrayed in Pride and Prejudice, where a young person needs to escape from her clueless family. The irritating presence of the mother in the film, and the quickness with which her two children appear to make life-determining decisions following her death, seem to invite discussions of plot and character organized around ideas of individual development, self-improvement and understanding. This is the territory of the desire plot, an account of family history captured for the twentieth century by Freudian-Lacanian readings which position sexual desire within the unconscious history of familial fantasies, understood as vertical and Oedipal. In this territory, mothers and old ladies become, as Mary Jacobus memorably phrased it, little more than "the waste products" of a system in which marriageable women are objects of exchange between men (142) and a mother's death would be expected to grease the wheels of narrative. Identity and narrative are inextricably linked here: a certain understanding of narrative as developmental and teleological paves the way for an understanding of identity as either/or. There are problems, however, in trying to read ABCD as a bildüngsroman structured by what Susan Freidman calls "the temporal plots of the family romance, its repetitions and discontents" (137), rendering the "Indian" characteristics of the plot unreadable, and the apparently self-defeating nature of the characters' choices and behavior, rather pointless. A central [End Page 16] difficulty is that the film both responds to and resists readings based on the Oedipal model of the bildüngsroman with its focus on linear development through time.

What happens during natural protein fibre dissolution in ionic liquids

Here, we monitor the dissolution of several natural protein fibres such as wool, human hair and silk, in various ionic liquids (ILs). The dissolution of protein-based materials using ILs is an emerging area exploring the production of new materials from waste products. Wool is a keratin fibre, which is extensively used in the textiles industry and as a result has considerable amounts of waste produced each year. Wool, along with human hair, has a unique morphology whereby the outer layer, the cuticle, is heavily cross linked with disulphide bonds, whereas silk does not have this outer layer. Here we show how ILs dissolve natural protein fibres and how the mechanism of dissolution is directly related to the structure and morphology of the wool fibre. © 2014 by the authors; licensee MDPI, Basel, Switzerland.

The rat placental renin-angiotensin system - a gestational gene expression study

BACKGROUND: The placenta is an essential organ that provides nutrients and oxygen to the developing fetus and removes toxic waste products from the fetal circulation. Maintaining placental blood osmotic pressure and blood flow is crucial for viable offspring. The renin-angiotensin system (RAS) in the placenta is a key player in the regulation of maternal-fetal blood flow during pregnancy. Therefore, the aim of this study was to determine if RAS genes are differentially expressed in mid to late gestation in rat placenta. METHODS: Whole placental tissue samples from pregnant Sprague Dawley rats at embryonic (E) days 14.25, 15.25, 17.25 and 20 (n = 6 for each gestational age) were used for genome-wide gene expression by microarray. RAS genes with expression differences of >2 fold were further analyzed. Quantitative Real-Time PCR (qPCR) was performed on independent samples to confirm and validate microarray data. Immunohistochemisty and Western blotting were performed on a differentially expressed novel RAS pathway gene (ANPEP). RESULTS: Six out of 17 genes of the RAS pathway were differentially expressed at different gestational ages. Gene expression of four genes (Angiotensin converting enzyme (Ace), angiotensin converting enzyme 2 (Ace2), membrane metalloendopeptidase (Mme) and angiotensin II receptor 1A (Agtr1a)) were significantly upregulated at E20 whereas two others (Thimet oligopeptidase 1 (Thop1) and Alanyl aminopeptidase (Anpep)) were downregulated at E20 prior to the onset of labour. These changes were confirmed by qPCR. Western blots revealed no overall differences in ANPEP protein expression in the placentae. Immunohistochemical studies, however, indicated that the localization of ANPEP differed at E17.25 and E20 as ANPEP localization in the giant trophoblast cell of the junctional zone was no longer detectable at E20. CONCLUSIONS: The current study investigated the expression of members of the RAS pathway in rat placentae and observed significantly altered expression of 6 RAS genes at 4 gestational ages. These findings present the need for further comprehensive investigation of RAS genes in normal and complicated pregnancies.

Hydrolysis of citrus peel waste with recombinant rhamnosidase for bioenergy generation

Large amounts of Citrus peel (rich in poly-phenolic compounds) are generated as a by-product of the juice processing industry. Development of alternative, higher valued products utilizing peel waste from grapefruit, oranges, Valencia and other citrus fruit would benefit citrus juice processors by providing them with means to profitably process their peel waste and to avoid environmentally hazardous dumping. Citrus peel waste [CPW, comprised of peel, membranes and juice vesicles] contains a high level of polyphenols and has been used for the production of animal feed, single-cell protein, fibre, enzyme(s), immobilization support & bio-sorbent for heavy metal removal. Naringin (a major tri-hydroxy flavonoid glycoside) is available in large amounts in citrus peel, processed juice and can be extracted from citrus peel waste1. The extracted naringin is further hydrolysed by rhamnosidase to produce D-rhamnose for the production of ethanol and other fermentation products. We have produced a recombinant enzyme2 that has the ability to catalyse the cleavage of terminal rhamnoside groups from naringin to prunin and rhamnose. We have recovered important sugar “D-rhamnose” from the processed waste which would be utilized for ethanol production3. This presentation will summarize current efforts to develop an enzymatic treatment which would facilitate the economical processing of citrus waste for bioenergy generation.

Emerging technologies for recovery of value-added components from olive leaves and their applications in food/feed industries

Olive leaves are the most abundant agricultural waste source rich in polyphenolics. Due to the numerous health benefits associated with these compounds, the interest in recovering polyphenols from olive leaves has increased in the scientific community over the last decade. Recent studies have focused on improved extraction techniques and processing methods that are most suited for agro-biological industries involved in the development of nutraceutical and functional products. The major problems in olive leaves processing include bitter taste and the low stability of various phenolic compounds. Oleuropein and hydroxytyrosol are the most important phenolic compounds extracted from olive leaves. The present review highlights the importance of olive leaves, their composition, preparation methods, major phenolic compounds, and commercial applications. This review article focuses on integrating studies on olive leaf extract (OLE) pertinent to nutrition, health, and beauty. The different board categories of delivery systems available for the encapsulation of OLE are given. These novel delivery systems could improve fortification, supplementation, and dietary diversification in food and pharmaceutical products.

Impact of ripening stages of banana flour on the quality of extruded products

The study investigated the physical, nutritional and sensory properties of different ripening stages of banana during extrusion processing in combination with rice flour to develop quality snack products. Dehydrated banana flours at ripening stages 4, 5 and 6 (peel colour) were mixed separately at 40% banana to 60% rice flour levels. The mixtures were extruded through a twin-screw extruder at 120 °C barrel temperature, 220 and 260 r.p.m, screw speed and 12% feed moisture. Increase in ripeness indicated negative effect on expansion and water absorption capacity while increasing the water solubility index and moisture retention (wet basis) of the products. Protein and mineral (except for zinc and copper) content of the products were significantly different (P < 0.05) from 4 to 6 of the ripening stages. Most of the essential amino acids in the extruded products increased significantly (P < 0.05) at the ripening stage of 6. All the products were within the acceptable range in the 9-point Hedonic scale showing the best texture and flavour scores for stage 4 and 6, respectively. The extruded products show potential as snack products because of their nutritional quality and sensory acceptability.

Use of wild fish and other aquatic organisms as feed in aquaculture; a review of practices and implications in the Asia Pacific

Global and Asian aquaculture have witnessed a ten-fold increase in production from 1980 to 2004. However, the relative percent contribution to production of each of the major commodities has remained almost unchanged. For example, the contribution of freshwater finfish has declined from 71 to 66 percent in Asia but has remained unchanged globally over the last 20 to 30 years. This fact has dictated trends in the use of fish as a feed for cultured stocks. The growth in the sector has gone hand in hand with an increasing dependence on fish as feed, either directly or indirectly. In a number of countries in the Asia-Pacific region, the aquaculture sector has surpassed the capture fisheries sector in its respective contributions to the gross domestic product (GDP). Aquaculture’s increased contribution to national GDPs can be taken as a clear indication of the contribution of the sector to food security and poverty alleviation. The use of finfish and other aquatic organisms as a feed source can be through direct utilization of whole or chopped raw fish in wet form, through fishmeal and fish oil in formulated feeds, and/or as live fish, although the latter is uncommon and the overall amounts used are relatively small. In the first two categories, the fish used are often termed “trash fish/low-value fish”. Although attempts have been made to define this term, all definitions have a certain degree of ambiguity and/or subjectivity. In this regional review, the amount of fish used as feed sources based on the above categories was estimated primarily from the production data, supported by assumptions on the inclusion levels of fishmeal in formulated feeds and observed feed conversion efficiencies for both formulated feeds and for stock fed trash fish/low-value fish directly. A scenario for the use of fish as feed was developed by starting from the levels of aquaculture production recorded in 2004 and assuming increases in production volumes of 10, 15 and 20 percent by 2010, respectively, for the three trajectories. In parallel, the pattern of wild fish use as feed was projected to change as fish and shrimp farmers increasingly replace farmmade feeds by incorporating trash fish/low-value fish with manufactured feeds that include fishmeal. Also, the fishmeal inclusion rates in manufactured feeds are falling slowly, and this has been incorporated into the projections. The regional review also deals with the production of fishmeal using trash fish/low-value fish in the Asia-Pacific region. Regional fishmeal production as a whole is relatively low when compared with that of major fishmeal-producing countries such as Chile, Iceland and Norway, amounting to approximately 1 million tonnes per year. However, there is a trend towards increasing the use of fish industry waste, such as from the tuna canning industry in Thailand. The fishmeal produced in the region is priced considerably lower than globally traded fishmeal, but its quality is poorer. Total fishmeal use in Asian aquaculture in 2004 was estimated as 2 388 million tonnes, the highest proportion of this being used for crustacean aquaculture (1 418 million tonnes). Based on growth predictions (to year 2010) in the sector and improvements to feed quality and management, it is expected that the quantity of fishmeal used in Asian aquaculture will be slightly less than at present. An estimated 240 000 tonnes of fish oil is used in Asian aquaculture, principally in shrimp feeds. Based on production estimates of commodities in 2004 that rely on trash fish/low-value fish as the main feed source, this regional review suggests that Asian aquaculture currently uses between 2 465 and 3 882 million tonnes, an amount that is predicted to decrease to between 1.890 and 2 795 million tonnes by 2010. The use of trash fish/low-value fish and fishmeal by the aquaculture sector has been repeatedly adjudicated as a non-sustainable practice, and globally the sector is seeking to reduce its dependence on fish as feed through improved feed management practices and development of better quality feeds and feed formulations using alternative ingredients. Over the next few years, decreases in the use of trash fish/low-value fish are also expected to be achieved through better conversion of raw materials into fishmeal and fish oil during the reduction processes. The “way forward” in addressing the issue of the use of fish as feed in aquaculture in the Asia-Pacific region includes the need for a concerted regional research thrust to reduce the use of fish as feed sources in aquaculture, as has been achieved in the animal husbandry sector. Secondly, there is a need to increase farmer awareness on the use of trash fish as feed. This is achievable, considering the similar progress that has been made by the region’s shrimp farming sector, which almost exclusively involves small-scale practitioners who are often clustered in a given locality. The analysis also suggests that the use of trash fish/low-value fish in aquaculture may be compatible with improving food security and alleviating poverty. In Asia, trash fish/low-value fish is mostly landed in areas where there are other suitable fish commodities for human consumption. To make the trash fish/low-value fish suitable and available for human consumption would involve some degree of value-adding and transportation costs, which are likely to increase the price to beyond the means of the consumer, particularly in remote rural areas. Under such a scenario, the direct or indirect use of this perishable resource as a feed source to produce a consumable commodity appears to make economic sense and appears to be the most logical use for overall human benefit. In this manner, trash fish/low-value fish contributes to food security by increasing income generation opportunities and hence contributes to poverty alleviation. Another factor that needs to be taken into account is the large numbers of artisanal fishers who harvest this raw material. The continued use of trash fish/low-value fish, therefore, allows these fishers to maintain their livelihoods¹. Admittedly, this is an area that warrants more detailed investigation, from resource use, livelihoods and economic viewpoints.

Fermentative production of rhamnosidase from Staphylococcus xylosus MAK 2 in a bioreactor for bio-energy generation

Increasing concern about the environment, food and feed shortages and hike in the price of petroleum have stimulated interest in new ways of producing biofuels. The interest is rapidly increasing towards converting agricultural wastes to commercially valuable products. Biofuels made from waste biomass can offer immediate and sustained greenhouse gas advantages. In this direction, we are focusing on Citrus processing waste, a byproduct of juice manufacture, which contains high amount of flavonoids and polysaccharides. There is a considerable industrial interest in the enzymatic transformation of flavonoids to hydrolysis products; that offers a pathway to bio-energy generation. Rhamnosidase of bacterial origin are very few and thus are potentially subject for research.

Staphylococcus xylosus, Gram positive cocci, a nonpathogenic member of CNS family, isolated from soil was used to produce α-L-rhamnosidase. This new strain, so far unknown for the production of α-L-Rhamnosidase, was identified and characterized as Staphyloccocus sp. through biochemical tests and 16S DNA sequence analysis. Effect of various medium and process parameters like pH, temperature, aeration and agitation rates and inducer concentration were studied. Further, the enzyme activity was enhanced by adding the inducer and divalent metal ion to the optimised fermentation medium. We have recovered important sugars “rhamnose” and “galacturonic acid” from the processed waste which would be utilized for ethanol production. This presentation will summarize current efforts to develop an enzymatic treatment which would facilitate the economical processing of citrus waste for bioenergy generation.

Environmentally friendly sound absorbing noise barrier made from concrete waste - further developments

This paper reports on the second phase of a research project aimed at the development of an environmentally friendly noise barrier for urban freeways, also known as KMAK [1]. The concrete barrier, which has some unique capabilities to mitigate transportation noise, is made from recycled concrete (RC) aggregate and industrial by-products such as fly ash and reclaimed water. The current developmental work expands on a research project that resulted in a two-layer (2L) concrete barrier. Two prototypes of the 2L barrier were produced, followed by extensive acoustic testing and a number of simulations where standard timber and/or concrete barriers were substituted with KMAK barrier [2]. Current research investigates a variety of architectural finishes applied to the original KMAK barrier with the aim of improving its visual appearance and also fine-tuning its acoustic performance. The new three-layer (3L) barrier optimizes sound absorption in a frequency range characteristic similar to that of transportation noise, especially road traffic noise. Three major aspects related to the development of architectural finishes were considered; environmentally responsible materials, surface features, and production methods. The findings of the current investigation demonstrate that there is a positive correlation between surface features, percentage of perforation as well as depth of the architectural layer, and increased potential of the 3L barrier to mitigate transportation noise. On average, the addition of perforated architectural finish contributes to a 20% increase in sound absorption. The preliminary results also show that the sound absorbency of the 3L barrier can be better controlled and tuned to specific noise frequency than the 2L type. The visual appearance has been significantly improved with the addition of the architectural finish, which makes the barrier an attractive, feasible, and viable alternative to road barriers made from standard concrete or timber.

The whole-body fatty acid balance method : examples of its potential for feed efficiency and product quality optimisation in fish and poultry

Dietary lipids and fatty acids are not only fundamental in determining animal performance, but also determine the eating qualities of animal products. Several methods have been used to quantify fatty acid metabolism but most involve expensive in vitro approaches that are not suitable for most laboratories. Furthermore, there is considerable variation between methods with regard to enzyme activity, which makes comparison of results between studies difficult. The recently developed whole-body fatty acid balance method (WBFABM) is a simple and reliable in vivo method for assessing fatty acid metabolism, including rates of liponeogenesis and de novo fatty acid production, β-oxidation of fatty acids and bioconversion (elongation and desaturation) of fatty acids to long-chain polyunsaturated fatty acids. Initially developed for implementation with a fish model, the WBFABM has proven to be a simple and effective method that can be used in any laboratory equipped with a gas chromatography unit. Since its development, it has been used in several farmed finfish feeding trials and in broiler chicken feeding trials. The WBFABM is currently used at research institutions worldwide and its use is increasing in popularity among animal scientists. With this method, it is possible to track the fate of individual dietary fatty acids within the body. The WBFABM could contribute significantly to information generated by animal feeding trials.

Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon

Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed.

Enzymes for food waste remediation and valorisation

Industrial food processing operations are among the largest contributors of environmental waste. The use of enzymes in food waste remediation and valorisation is the central theme of this chapter. Specifically, the chapter first discusses the sources and values of food waste in food supply chains. Different strategies for bioremediation of wastewater using enzymes are then reviewed. The last part of the chapter focuses on waste valorisation—how to turn food waste into valuable products using enzymes—including a discussion of emerging trends in this field.