Former foodstuffs in feed: a minireview of recent findings.

The sustainability of all productive activities, including livestock farming, becomes a fundamental challenge in the current scenario. Livestock production faces both old and new challenges related to climate change, food safety, and feed-food competition. The latter aspect has recently become a hot topic, and many researchers are turning their attention to this issue. According to circular economy principles, former foodstuffs have characteristics that make them a promising source of raw material for animal feed. The main objective of the present review is to provide a brief overview of the most recent studies (published between 2016 and 2022) addressing the dietary inclusion of former foodstuffs for livestock. The articles analyzed cover key findings from both in vitro and in vivo studies of former foodstuffs included in the diets for pigs, cows, and broilers, and assess the associated safety aspects. The articles provide information on livestock performances and product quality, as well as feed digestibility, fecal microbiota, and blood analysis. Although the evidence supports the inclusion of former foodstuffs in livestock diets as a safe, effective, and sustainable ingredient, this analysis of the most recent literature also highlights gaps in our knowledge that need to be filled. The present overview will help researchers plan future research and standardize and promote the inclusion of former food products in livestock diets.

Review: Pig-based bioconversion: the use of former food products to keep nutrients in the food chain.

The primary challenge of agriculture and livestock production is to face the growing competition between food, feed, fibre, and fuel, converting them from resource-intensive to resource-efficient. A circular economy approach, using agricultural by-products/co-products, in the livestock production system would allow to reduce, reuse, and redistribute the resources. Former food products (FFPs), also named ex-foods, could represent a valid option in strengthening resilience in animal nutrition. FFPs have a promising potential to be included regularly in animal diets due to their nutritive value, although their potential in animal nutrition remains understudied. A thorough investigation of the compositional and dietary features, thus, is essential to provide new and fundamental insights to effectively reuse FFPs as upgraded products for swine nutrition. Safety aspects, such as the microbial load or the presence of packaging remnants, should be considered with caution. Here, with a holistic approach, we review several aspects of FFPs and their use as feed ingredients: the nutritional and functional evaluation, the impact of the inclusion of FFPs in pigs' diet on growth performance and welfare, and further aspects related to safety and sustainability of FFPs.

Multivariate image analysis for the rapid detection of residues from packaging remnants in former foodstuff products (FFPs) - a feasibility study.

From a circular economy perspective, feeding livestock with food leftovers or former foodstuff products (FFPs) could be an effective option aimed at exploiting food leftover resources and reducing food losses. FFPs are valuable energy sources, characterised by a beneficial starch/sugar content, and also fats. However, besides these nutritional aspects, safety is a key concern given that FFPs are generally derived from packaged food. Packaging materials, such as plastics and paper, are not accepted as a feed ingredient which means that residues should be rigorously avoided. A sensitive and objective detection method is thus essential for an accurate risk evaluation throughout the former food production chain. To this end, former food samples were collected in processing plants of two different European countries and subjected to multivariate analysis of red, green, and blue (RGB) microscopic images, in order to evaluate the possible application of this non-destructive technique for the rapid detection of residual particles from packaging materials. Multivariate Image Analysis (MIA) was performed on single images at the pixel level, which essentially consisted in an exploratory analysis of the image data by means of Principal Component Analysis, which highlighted the differences between packaging and foodstuff particles, based on their colour. The whole dataset of images was then analysed by means of a multivariate data dimensionality reduction method known as the colourgrams approach, which identified clusters of images sharing similar features and also highlighted outlier images due to the presence of packaging particles. The results obtained in this feasibility study demonstrated that MIA is a promising tool for a rapid automated method for detecting particles of packaging materials in FFPs.

Reduce, Reuse, Recycle for Food Waste: A Second Life for Fresh-Cut Leafy Salad Crops in Animal Diets.

The world's population is growing rapidly, which means that the environmental impact of food production needs to be reduced and that food should be considered as something precious and not wasted. Moreover, an urgent challenge facing the planet is the competition between the food produced for humans and the feed for animals. There are various solutions such as the use of plant/vegetable by-products (PBPs) and former foodstuffs, which are the co/by-products of processing industries, or the food losses generated by the food production chain for human consumption. This paper reviews the by-co-products derived from the transformation of fresh-cut leafy salad crops. A preliminary nutritional evaluation of these materials is thus proposed. Based on their composition and nutritional features, in some cases similar to fresh forage and grasses, this biomass seems to be a suitable feedstuff for selected farm animals, such as ruminants. In conclusion, although the present data are not exhaustive and further studies are needed to weigh up the possible advantages and disadvantages of these materials, fresh-cut leafy salad crops represent a potential unconventional feed ingredient that could help in exploiting the circular economy in livestock production, thereby improving sustainability.

Occurrence and Antimicrobial Profile of Bacterial Pathogens in Former Foodstuff Meat Products Used for Pet Diets.

European legislation stipulates that food no longer intended for human consumption, due to commercial reasons, manufacturing problems, or some defect, can be used in pet feed. However, the presence of former foodstuffs in pet diets could constitute a public health issue because pets can act as reservoirs of antimicrobial resistance genes. In this study, for the first time, biological hazards due to the presence of Escherichia coli and Salmonella in former foodstuff meat products were evaluated. Among the 112 samples of packaged fresh meat (poultry, pork, and beef) collected from cold storage warehouses of a mass market retailer, the overall prevalence of E. coli and Salmonella, the prevalence of strains with multidrug resistance, the phenotypic and genotypic characteristics of strains that produce extended-spectrum ß-lactamase, and the presence of biofilm producers were assessed. A high prevalence of E. coli was observed in former foodstuffs of poultry (100%), pork (100%), and beef (93.3%). Salmonella Derby and Salmonella Typhimurium were found in 11.5% of the poultry samples, and Salmonella Typhimurium was found in 13.3% of the pork samples. Salmonella was not recovered from the beef samples. Multidrug resistance was found in E. coli and Salmonella isolates from poultry, pork, and beef. Overall, 18.2% of E. coli isolates and 20% of Salmonella isolates were resistant to various types of antibiotics with various mechanisms of action. Salmonella isolates from pork are an important source of extended-spectrum ß-lactamase production. Both E. coli and Salmonella were carriers of antibiotic resistance marker genes ( blaTEM, blaSHV, and blaCTX-M) associated with ß-lactamase production in poultry and pork. Approximately 30% of the E. coli isolates from the various types of meat were phenotypically biofilm producers, and all carried the fimH gene. These findings indicate that the use of former foodstuff meat products in pet diets can represent a risk for public health.