Evidencing the importance of the functional unit in comparative life cycle assessment of organic berry crops.

LCA methodology provides the best framework to evaluate environmental impacts in agriculture systems. However, the interpretation of LCA results, in particular when the objective was to compare different production systems, could be affected by the selection of the functional unit (FU). That is why an accurate definition of the FU, in agreement with the function considered for the systems analysed, is essential. In this work, the organic production at small scale of blueberry, raspberry, blackberry and cape gooseberry in North Spain has been analysed following LCA methodology. Although a different distribution of environmental loads was obtained for each crop, in all cases, the main contributions to most of the considered environmental categories were electric and fertiliser consumptions. The different production systems have been compared on the basis of the environmental impacts associated considering different FUs, i.e. based on fruit mass, cultivated area, farm-gate price and nutritional quality of fruits. Carbon footprints (CF) have been also calculated. It was observed that the order of the crops with respect to their environmental performances was the same for the blueberry and raspberry crops (with the lowest and the highest CF, respectively), independently of the selected FU, whereas the order of the blackberry and cape gooseberry crops was interchanged, depending on the FU used. This work supports the need of being aware of the final objective of the orchards when choosing the FU (i.e. producing fruits, cultivating an area, economic benefits or nourishing people), so that valid conclusions can be achieved from the environmental comparison, even for different agricultural products.

A standard analytical approach and establishing criteria for microplastic concentrations in wastewater, drinking water and tap water.

The ubiquitous presence of microplastics (MPs) in natural water bodies reflects the global issue regarding these micropollutants. The main problem of MPs lies on the difficulty of removing these particles from water during wastewater and drinking water treatments. The release of MPs to the environment in treated wastewater contributed to the dispersion of these micropollutants, which enhances the harmful effect of MPs on fauna and flora. In addition, their presence in tap water entails a potential risk to human health since MPs can be directly consumed. The first step is being able to quantify and characterise these microparticles accurately. In this work, a comprehensive analysis on the presence of MPs in wastewater, drinking water and tap water has been conducted with emphasis on sampling methods, pre-treatment, MP size and analytical methods. Based on literature data, a standard experimental procedure has been proposed with the objective of recommending a methodology that allows the homogenisation of MP analysis in water samples. Finally, reported MP concentrations for influents and effluents of drinking and wastewater treatment plants and tap water have been analysed, in terms of abundance, ranges and average values, and a tentative classification of different waters based on their MP concentrations is proposed.

Cocoa Bean Shell: A By-Product with High Potential for Nutritional and Biotechnological Applications.

Cocoa bean shell (CBS) is one of the main solid wastes derived from the chocolate industry. This residual biomass could be an interesting source of nutrients and bioactive compounds due to its high content in dietary fibres, polyphenols and methylxanthines. Specifically, CBS can be employed as a raw material for the recovery of, for example, antioxidants, antivirals and/or antimicrobials. Additionally, it can be used as a substrate to obtain biofuels (bioethanol or biomethane), as an additive in food processing, as an adsorbent and, even, as a corrosion-inhibiting agent. Together with the research on obtaining and characterising different compounds of interest from CBS, some works have focused on the employment of novel sustainable extraction methods and others on the possible use of the whole CBS or some derived products. This review provides insight into the different alternatives of CBS valorisation, including the most recent innovations, trends and challenges for the biotechnological application of this interesting and underused by-product.

Contribution of household dishwashing to microplastic pollution.

At household level, clothes washing has been recognised as an emitter of microplastics (MPs) into the environment and it is supposed that dishwashing is also a source of MPs, although little attention has been paid so far. In this work, the emission of MPs released from dishwashing procedures at household level has been studied. The effect of different parameters such as time, temperature and type of detergent has been analysed. In addition, the MP content of tap water has been evaluated in order to determine its contribution to the MPs in dishwasher effluent. Results showed that when the dishwasher was operated empty with a pre-wash programme (15 min and room water temperature), between 207 and 427 MPs were released per load (3 L), whereas this value increased notably with an intensive programme (164 min and water at 70 °C) (1025-1370 MPs per load, 15 L), which highlighted the effect of temperature and time on MP release. Additionally, when a polypropylene lunch box was washed, the number of MPs released increased by 14 ± 3 MPs and 166 ± 12 MPs of total. Finally, the influence of the use of detergent with the dishwasher empty and containing lunch boxes has been studied. With detergent, 35-54% more MPs were released from dishwasher accessories, whereas no additional release took place from lunch boxes. This work shows for the first time the important contribution of domestic dishwashing to MP pollution and the environmental benefits of using more environmentally friendly materials in both dishwashing machine accessories and food utensils.

Environmental advantages of coproducing beef meat in dairy systems.

Beef meat, one of the more environmentally costly animal-based foods, can be produced in two general ways, as the main product on specialised farms or as a co-product on dairy farms. In this study, two cases (a semi-confinement dairy farm (A) and a pasture-based dairy farm (B)) have been analysed by means of LCA to evaluate the environmental impacts associated with the coproduction of beef meat. In both cases, purchased feed production was found to be the main cause of environmental impacts in most of the categories considered. Additionally, cow emissions to air were the main contributor for the global warming category. Comparing the two dairy systems, notably lower environmental impacts were obtained for B in 13 of the 18 categories analysed. Regarding CF, 8.10 and 8.88 kg CO2eq/kg LW were obtained for A and B, respectively. These CF values were within the wide range found in the literature for beef meat (1.2-42.6 kg CO2eq/kg LW). Beef calves and cull cows are an important output of dairy farming, so that coproduction enables milk and meat with lower CF and associated environmental impacts to be obtained. In addition, the variability of the data found in literature and the lack of LCA studies based on real data for beef meat coproduced on dairy farms evidence the importance of in-depth study of this interesting topic.

Towards food circular economy: hydrothermal treatment of mixed vegetable and fruit wastes to obtain fermentable sugars and bioactive compounds.

Due to processing activity, fruits and vegetables generate notable amounts of wastes at the processing, retail, and consumption level. Following the European goals for reducing food wastes and achieving a circular economy of resources, these biowastes should be valorized. In this work, hydrothermal hydrolysis at different conditions (temperatures, times, waste/water ratio, pH values) were tested to treat for first time; biowastes composed of mixed overripe fruits or vegetables to maximize the extraction of fermentable sugars that can be used as substrates in bioprocesses. Experimental data were fitted by a model based on irreversible first-order reactions, and kinetic constants were obtained. When hydrolysis of fruit wastes was carried out at 135 °C and pH 5 during 40 min, more than 40 g of reducing sugars per 100 g of waste (dry weight) could be obtained (represents an extraction of 97% of total carbohydrates). Concentrations of inhibitor compounds (HMF, furfural, acetic acid) in the hydrolysates were very low and, as example, a fermentation to obtain bioethanol was successfully carried out with an efficiency above 95%. Additionally, the production by hydrothermal treatment of bioactive compounds was investigated and the best results obtained were 92% DPPH inhibition and 12 mg GAE/g (dry weight) for antioxidant activity and phenolic compounds, respectively. These values are similar or even higher than those reported in literature using specific parts of fruits and vegetables.

Assessment of the environmental impacts associated with vineyards and winemaking. A case study in mountain areas.

Mountain wines produced in specific mountain areas and following singular practices have gained popularity over the last few decades. During this time, the environmental impacts associated with the food and beverage manufacturing sector have become a question of interest. However, the environmental impacts derived from the production of this peculiar wine have scarcely been studied until now. A mountain winery in north Spain has been analyzed as representative of PDO "Cangas" winemaking by means of life cycle assessment (LCA). High-quality inventory data for one year of operation was obtained directly from this facility and two steps have been considered, the vineyard and the winery phases. The main factors involved in grape cultivation and wine production were included. In common with standard winemaking processes, the use of fertilizers and the production of glass bottles were the principal hotspots in the grape cultivation and wine production phases, respectively. Additionally, in the winery here evaluated, waste management also contributed notably to several impacts, mainly due to the employment of traditional practices such as the incineration in situ of vineyard pruning wastes. The carbon footprint obtained for "Cangas" PDO wine was 2.35 kg of CO2eq per 0.75-l bottle, a value within the range reported in the literature for different wines around the world (0.2-2.5 kg CO2eq per bottle). A sensitivity analysis has shown that changes in vineyard productivity and the amount of fertilizers applied to the land would strongly affect the environmental performance of the wine manufacturing process. Some alternative scenarios have been proposed, modifying the management of pruning wastes in the vineyard and the packaging material in the winery. Results showed that environmental impacts associated with the production of this mountain wine could be notably reduced simply by reusing a percentage of the bottles and/or composting the organic wastes. Specifically, the carbon footprint would be 40% lower if these two improvements were implemented. Considering the lack of similar studies, further research on the production of mountain wines should be carried out in other regions to increase the knowledge about the environmental impacts associated with the manufacturing of this singular type of wine.

Addition of Trans-Resveratrol-Loaded Highly Concentrated Double Emulsion to Yoghurts: Effect on Physicochemical Properties.

Trans-resveratrol (RSV) needs to be encapsulated to maintain its beneficial properties on the human body. This is due to its extreme photosensitivity, short biological half-life, and easy oxidation. In this study, the use of double emulsions for RSV encapsulation and their further application on functional yoghurts was studied. Different types of yoghurts were prepared: with and without RSV and with two types of volumetric emulsion formulations (20/80 and 30/70). In order to study the influence of the addition of double emulsions to the physical properties of the prepared yoghurts, they were characterised fresh and after a month under storage at 4 °C, in terms of droplet size, morphology, stability, rheology, texturometry, colorimetry, and antioxidant capacity. Results obtained showed that the presence of emulsion in the yoghurts produced a generalised decrease in the predominant droplet size (from 48 µm to 15-25 µm) and an increase in the stability. Additionally, a predominantly elastic character was observed. The firmness values obtained were very similar for all the yoghurts analysed and did not suffer important modifications with time. A slight colour variation was observed with storage time in the control sample, whereas a more notable variation in the case of emulsion yoghurts was observed. An appreciable increase of the antioxidant capacity of the final functional yoghurt (100 g) was observed when it contained 5-8 mg of RSV. Encapsulated RSV added to yoghurts presented a larger protection against RSV oxidation compared with free RSV, presenting a larger antioxidant inhibition after one month of storage. Moreover, the antioxidant capacity of yoghurts with encapsulated RSV was not affected under storage, since slight reductions (3%) were registered after one month of storage at 4 °C.

Bioremediation as a promising strategy for microplastics removal in wastewater treatment plants.

Microplastics (MPs) attract ever-increasing attention due to environmental concerns. Nowadays, they are ubiquitous across ecosystems, and research demonstrates that the origin is mainly terrestrial. Wastewater treatment plants (WWTPs) are a major source of MPs, especially fibres, in water masses. This review is focused on understanding the evolution and fate of microplastics during wastewater treatment processes with the aim of identifying advanced technologies to eliminate microplastics from the water stream. Among them, bioremediation has been highlighted as a promising tool, but confinement of microorganisms inside the WWTP is still a challenge. The potential for MPs bioremediation in WWTPs of higher aquatic eukaryotes, which offer the advantages of low dispersion rates and being easy to contain, is reviewed. Animals, seagrasses and macrophytes are considered, taking into account ecoethical and biological issues. Necessary research and its challenges have been identified.

Approaching the environmental problem of microplastics: Importance of WWTP treatments.

The undeniable presence of microplastics (MPs) in soil, air and, especially, in the aquatic environment has revealed them to be an emerging pollutant. One of the main sources contributing to the release of these microplastics into the environment is wastewater treatment plants (WWTPs). During the treatment of wastewater, these microparticles undergo incomplete retention, which leads to their discharge in huge amounts into water masses. The microplastics removed from the wastewater during the treatment processes usually become entrained in the sewage sludge, which is commonly employed as organic fertilizer. Alarming data regarding the occurrence of MPs in nature and the increasing public awareness of environmental concerns have led to the appearance of numerous studies on this topic in recent years. So, this work is focused on providing an overview of available processes for the removal of microplastics from water and also from sediments. Social demand for the correct and effective management of microplastics is constantly increasing and should be given careful consideration before future action is taken. Recycling is a good option, and policies might be developed in this direction, moving towards a circular and sustainable economy for plastics.

Enhancing trans-Resveratrol loading capacity by forcing W1/O/W2 emulsions up to its colloidal stability limit.

Trans-Resveratrol (3, 5, 4'-trihydroxystilbene) is a naturally occurring polyphenol easily oxidizable and extremely photosensitive with a short biological half-life that must be encapsulated to maintain its beneficial properties on the human body. The aim of this work is to increase the amount of resveratrol encapsulated using concentrated double water-in-oil-in-water (W1/O/W2) emulsions, making these systems more interesting as ingredient for functional food products and/or pharmaceutical formulations. The concentration of the inner emulsion (W1/O) for several external (W1O/W2) ratios was optimized in terms of encapsulation efficiency (EE), colloidal stability and rheological behaviour. W1/O emulsions formulated with ratios of 30/70 and 40/60 were used to obtain double emulsions (with ratios of 20/80 up to 80/20 of W1O/W2). Trans-Resveratrol EE increased up to 90 % when the most concentrated double emulsions were prepared for both W1/O ratios tested. The maximum resveratrol concentrations on double emulsions were 10.8 mg/L and 14.4 mg/L when 30/70 and 40/60 of W1/O ratios were used, respectively. However, longer time stability was found for double high internal phase emulsions (W1O/W2) with a ratio of 30/70 of W1/O. The double emulsion formulated with a 80/20 W1O/W2 volumetric ratio together with 30/70 of W1/O seems suitable to be used as ingredient for pharmaceutical and food devices/products due to its high colloidal stability, clearly pseudoplastic and elastic behaviour, high EE and large trans-Resveratrol carrier capacity.

Overview on GHG emissions of raw milk production and a comparison of milk and cheese carbon footprints of two different systems from northern Spain.

Milk production has been estimated to contribute 3-4% of anthropogenic greenhouse gas (GHG) emissions. However, the carbon footprint associated with raw milk can vary, depending on a variety of factors, such as the geographical area, species of cow and production system. In this study, a global overview of research published on the carbon footprint (CF) of raw cow milk is provided. Additionally, two different dairy systems (semi-confinement and pasture-based) have been analysed by life-cycle assessment (LCA) in order to determine their effect on the CF of the milk produced. Inventory data were obtained directly from these facilities, and the main factors involved in milk production were included (co-products, livestock food, water, electricity, diesel, cleaning elements, transport, manure and slurry management, gas emissions to air etc.). In agreement with reviewed literature, it was found that the carbon footprint of milk was basically determined by the cattle feeding system and gas emissions from the cows. The values of milk CF found in the systems under study were within the range for cow milk production worldwide (0.9-4.7 kgCO2eq kgFPCM-1). Specifically, in the semi-confinement and the pasture-based dairy farms, 1.22 and 0.99 kgCO2eq kgFPCM-1 were obtained, respectively. The environmental benefits obtained with the pasture grazing system are not only mainly due to the lower use of purchased fodder but also to the allocation between milk and meat that was found to be a determining methodological factor in CF calculation. Finally, data from the evaluated dairy systems have been employed to analyse the influence of raw milk production on cheese manufacturing. With this aim, the CF of a small-scale cheese factory has also been obtained. The main subsystems involved (raw materials, water, electricity, energy, cleaning products, packaging materials, transport, wastes and gas emissions) were included in the inventory of the cheese factory. CF values were 16.6 and 14.7 kgCO2eq kg-1 of cheese for milk produced in semi-confinement and pasture-based systems, respectively. The production of raw milk represented more than 60% of CO2eq emissions associated with cheese, so the primary production is the critical factor in reducing the GHG emissions due to cheese making.

Environmental impact of cheese production: A case study of a small-scale factory in southern Europe and global overview of carbon footprint.

The environmental performance of a small-scale cheese factory sited in a NW Spanish region has been analysed by Life Cycle Assessment (LCA) as representative of numerous cheese traditional factories that are scattered through the European Union, especially in the southern countries. Inventory data were directly obtained from this facility corresponding to one-year operation, and the main subsystems involved in cheese production were included, i.e. raw materials, water, electricity, energy, cleaning products, packaging materials, transports, solid and liquid wastes and gas emissions. Results indicated that the environmental impacts derived from cheese making were mainly originated from raw milk production and the natural land transformation was the most affected of the considered categories. On the contrary, the manufacturing of packaging material and other non-dairy ingredients barely influenced on the total impact. Additionally, an average carbon footprint of the cheeses produced in the analysed facility has also been calculated, resulting milk production and pellet boiler emissions the most contributing subsystems. Furthermore, it was notable the positive environmental effect that entailed the direct use of whey as animal feed, which was considered in this study as avoided fodder. Finally, a revision of published works regarding the environmental performance of cheese production worldwide was provided and compared to results found in the present work. According to the analysed data, it is clear that the content of fat and dry extract are determinant factors for the carbon footprint of cheeses, whereas the cheesemaking scale and the geographical area have a very low effect.

Microbial diversity on commercial eggs as affected by the production system. A first approach using PGM.

A novel DNA-based technique (PGM) has been employed for first time to analyse commercial eggs with the advantage of allowing an exhaustive identification of the microbiota present. Eggs from two different production systems, i.e. a free range system and a cage system, were analysed. Twenty-one and twenty-two phyla were identified on the surface of cage system and free range system eggs, respectively. In both cases, Firmicutes was the dominant phylum (representing around 50% of total phyla), being found families frequently reported to be present in the intestinal microbiota of chickens or hens, such as Clostridiaceae, Ruminococcaceae and Lachnospiraceae. Additionally, other phyla and families not previously described in association with eggshells could also be identified in this work. Most of the potential pathogenic genera associated with eggs (Salmonella, Clostridium, Helicobacter, Pseudomonas and Staphylococcus) showed higher incidence in eggs coming from cage systems than in eggs coming from free range systems, although the abundance of these genera were very low in both cases (<5% of total bacteria).

Treatment of supermarket vegetable wastes to be used as alternative substrates in bioprocesses.

Fruits and vegetables have the highest wastage rates at retail and consumer levels. These wastes have promising potential for being used as substrates in bioprocesses. However, an effective hydrolysis of carbohydrates that form these residues has to be developed before the biotransformation. In this work, vegetable wastes from supermarket (tomatoes, green peppers and potatoes) have been separately treated by acid, thermal and enzymatic hydrolysis processes in order to maximise the concentration of fermentable sugars in the final broth. For all substrates, thermal and enzymatic processes have shown to be the most effective. A new combined hydrolysis procedure including these both treatments was also assayed and the enzymatic step was successfully modelled. With this combined hydrolysis, the percentage of reducing sugars extracted was increased, in comparison with the amount extracted from non-hydrolysed samples, approximately by 30% in the case of tomato and green peeper wastes. For potato wastes this percentage increased from values lower than 1% to 77%. In addition, very low values of fermentation inhibitors were found in the final broth.

Eggshell waste as catalyst: A review.

Agricultural wastes are some of the most emerging problems in food industries because of their disposal cost. However, it is also an opportunity for the bioeconomy society if new uses for these residual materials can be found. Eggshells, considered a hazardous waste by UE regulations, are discarded, amounting hundreds of thousands of tonnes worldwide. This egg processing waste is a valuable source material, which can be used in different fields such as fodder or fertilizer production. Additionally, this residue offers interesting characteristics to be used in other applications, like its employment as an environment-friendly catalyst. In the present review we provide a global view of eggshell waste uses as catalyst in different processes. According to reviewed researching works, a huge variety of added value products can be obtained by using this catalyst which emphasised the interest of further investigations in order to widen the possible uses of this cheap green catalyst.

Gels prepared from egg yolk and its fractions for tissue engineering.

New biomaterials prepared from egg yolk and its main fractions (plasma and granules) have been developed for use in tissue engineering. Protein gels obtained via transglutaminase cross-linking were characterized by rheometry, texturometry and scanning electron microscopy. All the gels exhibited suitable physical and mechanical characteristics for use as potential biomaterials in skin regeneration. Specifically, results showed that these materials presented a compact, uniform structure, with granular gel being found to be the most resistant as well as the most elastic material. Accordingly, these gels were subsequently evaluated as scaffolds for murine fibroblast growth. The best results were obtained with granule gels. Not only adhesion and cell growth were detected when using these gels, but also continuous coatings of cells growing on their surface. These findings can be attributed to the higher protein content of this fraction and to the particular structure of its proteins. Thus, granules have proved to be an interesting potential raw material for scaffold development. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1577-1583, 2016.

Wet oxidation of activated sludge: transformations and mechanisms.

Wet oxidation (WO) is an interesting alternative for the solubilization and mineralization of activated sludge. The effects of different temperatures (160-200 °C) and pressures (4-8 MPa), on the evolution of chemical composition and rheological characteristics of a thickened activated sludge during WO are analyzed in this work. Soluble COD increases initially to a maximum and then diminishes, while the apparent viscosity of the mixture falls continuously throughout the experiment. Based on the experimental evolution of the compositions and rheological characteristics of the sludge, a mechanism consisting of two stages in series is proposed. Initially, the solid organic compounds are solubilized following a pseudo-second order kinetic model with respect to solid COD. After that, the solubilized COD was oxidized, showing a pseudofirst kinetic order, by two parallel pathways: the complete mineralization of the organic matter and the formation of highly refractory COD. Kinetic parameters of the model, including the activation energies are mentioned, with good global fitting to the experiments described.