• Energy Research

The paper aims at evaluating the potential biogas production, both in terms of CH4 and theoretical energy potential, from globe artichoke agricultural byproducts in Sardinia. Field data about the productivity of byproducts were collected on five artichoke varieties cultivated in Sardinia, to assess the biomethane production of their aboveground non-food parts (excluding the head). Moreover, secondary data from previous studies and surveys at regional scale were collected to evaluate the potential biogas production of the different districts. Fresh globe artichoke residues yielded, on average, 292.2 Nm3·tDOM−1, with dissimilarities among cultivars. Fresh samples were analyzed in two series: (a) wet basis; and (b) wet basis with catalytic enzymes application. Enzymes proved to have some beneficial effects in terms of anticipated biomethane availability. At the regional level, ab. 20 × 106 Nm3 CH4 could be produced, corresponding to the 60% of current installed capacity. However, districts potentials show some differences, depending on the specific biomass partitioning and on the productivity of cultivated varieties. Regional assessments should encompass the sensitiveness of results to agro-economic variables and the economic impacts of globe artichoke residue use in the current regional biogas sector.

The current concerns on global energy security, climate change, and environmental pollution represent some of the major elements of the growing interest on renewable energy. In this framework agro-food energy systems are at the center of a twofold debate: on the one hand they represent a key option for energy production while on the other their sustainability is threatened by the expansion of the bioenergy market that could lead to negative social and environmental consequences. The aim of this work is to evaluate—through a case study—the technical and economic feasibility of the replacement of energy crops (ECs) with used cooking oil (UCO) in an anaerobic digestion (AD) full-scale plant. At this purpose, a full-scale plant performing AD was monitored for two years. Three scenarios were developed and compared to evaluate the impacts and the potential benefits in terms of land saving in case of a substitution of ECs with UCO. Results highlighted a reduction of land use of over 50% if UCO is introduced in co-digestion with ECs. The lack of an appropriate legislative framework limits the utilization of used cooking oils (UCOs) in AD with a consequently missed opportunity for biogas owners that could find an important alternative in UCO.

The expected decline in availability of fossil fuels over the next several decades, either because of resource depletion or because of limits on carbon emissions, is leading to a keen interest in finding more sustainable energy sources. For this reason, it is useful to assess the energy footprint of alternative agricultural systems for crops and animal production and to identify potential transition scenarios to systems largely based on renewable energy. The present work aims to assess for the first time a comparative analysis of energy inputs in rice production systems in Southern Europe (Piemonte, Italy) and in North America (Missouri, USA). A total of twelve rice farms, either conventional or organic, were selected, collecting detailed data on direct (fuel and electricity) and indirect (machinery, fertilizers, pesticides, and seeds) energy inputs. While energy input of conventional farms ranged from 3.5 to 7 MJ/kg paddy rice, organic farming could reduce inputs by more than 50% with only 8% yield decrease. A significant reduction in fuel or electricity use can be achieved also with no till and surface irrigation. The use of renewable energy sources, as already practiced by some farms, could more than cover their electrical energy requirements.

About one third of all food produced for human consumption is wasted. Along with a lively debate on food loss and waste definition and quantification, growing attention is dedicated to the faceted dimensions of consumers’ food waste. Drivers, effects, and mitigating factors have been mainly studied in isolation, with limited attention paid to their interrelationships. This study aims to contribute to a better understanding of the underlying relationship between the causes of food waste and consumers’ perception of their role and of their concern on food waste effects and mitigating factors. The article draws on a survey submitted to 938 respondents while shopping at a supermarket in Italy in 2015. Data were processed by principal components to identify latent dimensions of consumer behavior, and a cluster analysis was performed to identify homogenous groups of consumers. Results emphasize the complexity of the relationship between consumers and food resources. They suggest that while consumers are aware about food waste as a global issue, they often fail to identify the individual contribution they might provide for its prevention and reduction. The article also detects three groups of consumers with different approaches to food waste management and a specific perception of the food waste phenomenon.

Using an original survey conducted in eight countries in 2021 (Canada, China, Germany, Italy, Russia, Spain, the UK, and the USA), this study explored the relationship between household food waste and dietary habits through a cross-country comparative perspective. In total, 8000 questionnaires were recorded from samples representative of the adult population of each country through an online survey conducted between the 13th and the 24th of August. The questionnaires were developed from the Waste Watcher International Observatory on Food and Sustainability, an international study of the social, behavioral, and lifestyle dynamics behind household food waste. The relationships between the per capita self-reported amount of food waste (expressed in kilocalories) and self-declared dietary habits (traditional, healthy and sustainable, vegetarian, smart, and confused) were estimated using multiple linear regression models. The results showed that smart diets are associated with higher values of food waste in Canada, Spain, the UK, and the USA. Vegetarian diets are associated with lower food waste values in China, Germany, the UK, and the USA, but not in Italy, Russia, and Spain. The share of the population adopting a smart diet was, on average, 2.7% of the sample; therefore, interventions for food waste reduction should focus on these specific types of consumers, who are often associated with larger amounts of food waste.

The energy intensity of modern food systems represents a major issue in a scenario of decreasing oil resources and increasing population. Beside the use of renewable energy, an increased efficiency in food systems could contribute to reduce fossil fuels dependence. In this sense, food losses and waste (FLW) have crucial consequences on the energy balance. Based on the concept of “embodied energy”, food wastage can be framed as a double waste of energy, both in terms of non-consumed food energy and the inputs used for production. Secondary data regarding direct and indirect energy inputs and FLW have been collected for the Italian food chain to estimate the embodied energy of food waste. Since in 2011 the production and distribution of food implied the use of 822 PJ and 18 Mt of food was discarded, 67 PJ of food energy and 100 PJ of embodied energy were wasted. These figures are equivalent to 12.2% of the total nutritional energy output and to 1.3% of the final energy use in Italy, respectively. The concept of double energy waste sheds new light on the intertwined relationship between energy and food security, suggesting that appropriate food waste reduction policies could result in a higher food production level and relevant energy savings.

Abstract Residues from the food manufacturing industry require management options with the best overall environmental outcome. The identification of sustainable solutions depends however, on many influencing factors such as energy input, transport distance, and substituted product. This study shows the influence of the choice of substituted products on the overall greenhouse gas (GHG) emissions for three specific food side-flows and their treatment in the European Union: animal blood, apple pomace and brewers’ spent grain (BSG). In a direct comparison of possible treatment options, it is notable that the conversion to food ingredients (valorisation) does not always result in reduced environmental net impacts (GHG savings), which means that other options at lower levels of the waste hierarchy might be more beneficial to the environment. The further use of apple pomace or BSG for the production of food ingredients is only advantageous if the processing emissions are smaller than the emissions from the substituted products. The use of food side-flows as animal feed shows environmental advantages in all scenarios, as the use of conventional feed, such as soybean meal or hay, is reduced and so are the GHG emissions. The anaerobic digestion of food side-flows is associated with significant GHG emissions, but alternative energy also display a high GHG factor when based on fossil resources. The measuring of circularity in the food sector is a challenge in itself due to the complexity of renewable materials. This study shall help to understand the interwoven influences of certain parameters to the results.