Mesophilic Anaerobic Co-digestion of Olive-Mill Waste With Cattle Manure: Effects of Mixture Ratio

The co-digestion of agri-food by-products and livestock manure is a feasible alternative for waste management and the recovery of biogas provides an option to generate renewable energy. A series of batch experiments were carried out in order to investigate the mesophilic anaerobic co-digestion of two-phase olive-mill waste (2POMW) and cattle manure (CM) in different mixtures (2POMW:CM = 50:50; 60:40; 75:25; 85:15). In addition, the biodegradability of the co-substrates was studied in order to analyze the performance of the co-digestion process. The results obtained in this study indicate that 2POMW has a low biodegradability since a high soluble organic matter concentration and a low accumulated methane production were obtained at the end of the corresponding biodegradability test. However, CM is more easily biodegradable in mesophilic anaerobic conditions. The co-digestion of both wastes produced an enhancement of the hydrolytic-acidogenic phase, increasing the organic matter potentially bioavailable as volatile fatty acids (VFAs) and the biogas productivity, as a consequence of the subsequent degradation of VFAs by methanogens. However, an accumulation of VFA, principally propionic acid, was observed in the reactors with higher proportions of 2POMW. The volatile solids (VS) removal increased with the 2POMW percentage of the mixture up to 75% fresh weight. The increase of 2POMW above 75% led to a decrease in total VS removal. Moreover, a decrease in methane production was observed for the 85:15 mixture, as a consequence of the high concentration of propionic acid, which is a known inhibitor of methanogenesis. The maximum cumulative methane production and methane yield were achieved in the 75:25 mixture with values of 18.70 L and 112.40 LCH4/kgVS(added), respectively. Compared with 2POMW, the co-digestion produced an increase of 264-319% in the volume of accumulated methane (L), 293-351% in the methane yield (LCH4/kgVS(added)) and 312-342% based on the VS consumed (LCH4/kgVS(removed)). These results suggest that the mixture of these agro-industrial by-products could be effective to enhance biogas production and organic matter removal from 2POMW

State of the art: public health and passenger ships

Background. The purpose of this report is to describe issues relevant to public health and to review all passenger ship associated diseases and outbreaks. Moreover, legislation and practices on sanitation and diseases surveillance related to ships internationally were also reviewed. Some relevant historical information about infections on merchant ships is provided as well. Material and methods. The methods used to develop the state-of-the-art report included a scientific literature review and an extensive and thorough search of the websites of organisations and government departments. A considerable effort was made to capitalise on previous experience in the field. In particular, for the literature review, a total of 158 scientific articles were used including 91 full papers and 67 abstracts, 7 guidelines published by the WHO, and 13 guideline documents published by other organisations. Moreover, 5 international conventions relevant to passenger ships were identified. Results. At the international level, public health issues related to ships are regulated by the revised International Health Regulations (2005). Other conventions of the International Maritime Organization regulate safety on board ships and waste and ballast water management, while conventions of the International Labour Organization regulates issues related to working conditions on board ships. Guidelines for preventing and controlling public health threats on board ships can be found in seven Guidelines published by the World Health Organization, including the WHO Guide to Ship Sanitation, which provides a framework for policy making and local decision making. The literature review results revealed that the infections/outbreaks that occur on passenger ships include Norovirus, Legionella spp., Salmonella spp., E. coli, Vibrio spp., and influenza A and B virus. The modes of transmission include person to person, waterborne, foodborne, airborne, and vectorborne, and shore excursions are responsible for some outbreaks. Conclusions. The industry (especially the ferry industry) and sanitary organisations can enhance collaboration in order to implement integrated hygiene programmes and prevent the occurrence of communicable diseases aboard passenger ships

Influence of Soy Protein Isolate on Gelatin-based Edible Film Properties

Gelatin is a biopolymer that can be obtained from the partial hydrolysis of collagen skin tissue of chicken leg. This study aims to utilize gelatin of chicken leg skin in combination with soy protein isolate (SPI) as raw material for edible film production. The experiment was initiated by extracting gelatin and edible film was prepared by mixtures of SPI in ethanol solution and gelatin solution (containing 1% chitosan, w/v) with different weight ratio for SPI : gelatin (1:1, 1:2, 1:3, 1:4, and 1:5) then heated at 70 °C for 45 min and added 10% glycerol. Furthermore printed and dried in oven for 24 h at 60 °C. The yield of preparation of gelatin from chicken leg skin was obtained about 40.3%. Higher concentration of gelatin in solution gives a transparent color and smooth surface of edible film. Base on mechanical properties analysis, the composition of 1:3 has the best result of tensile strength and elongation at break about 4.80 MPa and 113.37%, respectively. The antibacterial activity test showed low antibacterial activity with a 0.3 cm inhibit zone

Agro-materials : a bibliographic review

Facing the problems of plastic recycling and fossil resources exhaustion, the use of biomass to conceive new materials appears like a reasonable solution. Two axes of research are nowadays developed : on the one hand the synthesis of biodegradable plastics, whichever the methods may be, on the other hand the utilization of raw biopolymers, which is the object of this paper. From this perspective, the “plastic” properties of natural polymers, the caracteristics of the different classes of polymers, the use of charge in vegetable matrix and the possible means of improving the durability of these agro-materials are reviewed

Lamb meat quality assessment by support vector machines

The correct assessment of meat quality (i.e., to fulfill the consumer's needs) is crucial element within the meat industry. Although there are several factors that affect the perception of taste, tenderness is considered the most important characteristic. In this paper, a Feature Selection procedure, based on a Sensitivity Analysis, is combined with a Support Vector Machine, in order to predict lamb meat tenderness. This real-world problem is defined in terms of two difficult regression tasks, by modeling objective (e.g. Warner-Bratzler Shear force) and subjective (e.g. human taste panel) measurements. In both cases, the proposed solution is competitive when compared with other neural (e.g. Multilayer Perceptron) and Multiple Regression approaches

Relationship between galactomannan structure and physicochemical properties of films produced thereof

In this work five sources of galactomannans, Adenanthera pavonina, Cyamopsis tetragonolobus, Caesalpinia pulcherrima, Ceratonia siliqua and Sophora japonica, presenting mannose/galactose ratios of 1.3, 1.7, 2.9, 3.4 and 5.6, respectively, were used to produce galactomannan-based films. These films were characterized in terms of: water vapour, oxygen and carbon dioxide permeabilities (WVP, O 2 P and CO 2 P); moisture content, water solubility, contact angle, elongation-at-break (EB), tensile strength (TS) and glass transition temperature (T g ). Results showed that films properties vary according to the galactomannan source (different galactose distribution) and their mannose/galactose ratio. Water affinity of mannan and galactose chains and the intermolecular interactions of mannose backbone should also be considered being factors that affect films properties. This work has shown that knowing mannose/galactose ratio of galactomannans is possible to foresee galactomannan-based edible films properties.The authors thank the fellowship (SFRH/BPD/ 72753/2010) from the Fundação para a Ciência e Tecnologia (FCT, Portugal). The authors also thank the FCT Strategic Project of UID/BIO/ 04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-010124-FEDER-027462) and the project BBioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa OperacionalRegionaldoNorte(ON.2–ONovoNorte),QREN,FEDER. Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico – FUNCAP, CE Brazil (CI1-0080-00055.01.00/13)

Buying seafood: Understanding barriers to purchase across consumption segments

Most consumers have positive attitudes toward seafood and consider it to be an important part of a healthy and balanced diet. However when purchasing seafood, consumers also weigh up various risks which may act as barriers to consumption. In this paper, the findings of an online survey of Australian consumers (. n=. 899) which explored both drivers and barriers to seafood consumption are discussed. The primary focus of this paper is to explore the perceived risks of seafood consumption and how these vary across consumption levels. Perceived risks associated with seafood consumption include functional, social, physical, psychological, and financial risk. With the exceptions of physical and financial risk, perceptions of risk varied across regular, light and very light seafood consumption segments. Lighter fish consumers were more likely to perceive functional risk associated with being less informed and less familiar with fish, experience more difficulties with selecting fish, recognising if fish is fresh, and preparing and serving fish than more regular fish consumers. Regular seafood consumers were less likely than lighter seafood consumers to perceive social risk arising from other members of their household not liking fish. Moreover, regular seafood consumers were less likely to perceive psychological risks associated with unpleasant past experiences or unpleasant sensory qualities, such as not liking the smell of fish and not liking to touch fish. Based on these results strategies for reducing perceived risks as a means of stimulating fish consumption are proposed for further investigation. © 2012