We investigated how different carbonized materials, or chars (olive mill pomace biochar (BC) and urban greens pruning residues hydrochar (HC)) affect an important member of soil fauna, the terrestrial isopod Porcellio scaber. The selection behavior of isopods towards chars after a 48 h exposure was studied in (i) soil-char amended tests with single and multiple choices, and (ii) tests with chars offered as pure material. Finally, we exposed the isopods to char-amended soils for a period of 14 days to follow the effect on food consumption, body mass and activities of enzymes that are commonly altered upon stressor exposure (acetylcholinesterase, AChE, and glutathione S-transferase, GST). We showed that isopods are able to select between char amended and un-amended soil and different forms of char amendments: a clear preference for BC, and avoidance of HC were evidenced. The preferences remained the same when the chars were sterilized leading to the conclusion that initial microorganism composition was not the reason for selection, but selection was governed by other chars’ physico-chemical properties. It remains to be elucidated which of these properties were the dominant reason for the selection. We also showed that isopods intentionally use BC as food at a similar rate to alder leaves. Medium-term exposure to HC resulted in adverse effects on isopods because it led to reduced feeding and growth, in addition to increasing GST activity, although no alterations in AChE activity were found. We suggest that behavioral tests with P. scaber could be used as a fast, reliable and economically feasible screening method for determining the safety of chars for the soil environment. Results represent significant contribution in the field of char toxicity testing, highlighting the importance of tests with isopods as important members of soil meso fauna, with the aim of influencing environmental policies and quality standards.

Worldwide, large amounts of food are wasted every year. Reducing of food waste at European level is taken very seriously and it has been adopted even a target of reducing the amount of food waste in half until 2030. In many countries of the European Union, food wastes are composted, while in countries like Romania, the composting is too little used or not at all, but efforts are being made to apply this process. Food waste composting should take place both at the composting plants and housing level. An important step before starting the composting process is to establish an appropriate recipe. Therefore, the aim of this paper is to develop a composting recipe starting from investigation of food waste like peel and pomace of fruits (apple, banana, orange, and kiwi) and vegetables (potato, cabbage, and carrots) which are very common in waste generated at the housing level. The most important physical-chemical parameters were investigated in this study. Results show that pH of fruit waste is acid (4.0–5.0), while for vegetable waste, the pH is slightly higher (between 6.0 and 6.5). For all types of food waste, a very high moisture content (80–90%) was registered, while the nitrogen content is below 1%. Considering that C/N ratio is one of the most essential parameters, for the process to be carried out in good conditions, we have used regression analysis in order to determine the amounts of fruits and vegetable waste necessary to obtain different C/N ratios.

Effects of dietary supplementation of Emblica officinalis fruit (Indian gooseberry) pomace (EFP), a waste from fruit processing plants and rich in polyphenolic compounds, were investigated for ruminal fermentation, nutrient utilization, methane production, and milk production performance in buffaloes. An in vitro experiment was conducted using 0 to 50 g/kg of EFP (six treatments) to select an optimum dose for feeding of buffaloes. Organic matter (OM) degradability, total volatile fatty acid concentration, and acetate proportion decreased, but propionate proportion increased at the higher doses (> 30 g/kg). Methane production also decreased at the higher doses (≥ 20 g/kg). In the in vivo study, ten lactating buffaloes were randomly allotted into control and EFP groups (n = 5/group). The control group was fed a total mixed ration, whereas the EFP group was fed the control ration along with EFP at 20 g/kg of dry matter (DM) intake for 120 days. Feeding of EFP to buffaloes improved milk yield (P < 0.01) and milk production efficiency (P < 0.01). Concentration of milk protein tended (P = 0.071) to increase and that of solid not fat increased (P = 0.032) due to the EFP feeding. Yields (kg/day) of milk fat (P = 0.026), solid not fat (P = 0.011), and protein (P = 0.002) were greater in the EFP group than the control group. Somatic cell count in milk decreased (P = 0.032) due to EFP feeding. Digestibility of ether extract (P < 0.001) increased and OM (P = 0.051) tended to increase by EFP feeding. Methane production (g/d), yield (g/kg DM intake or g/kg digestible organic matter intake), and intensity (g/kg milk, g/kg milk fat, or g/kg milk protein), and methane conversion rate (percentage of gross energy intake) were lower (P < 0.01) in the EFP group than the control group. For milk fatty acid (FA) profiles, total saturated FA proportion tended to be greater (P = 0.057) in the EFP group than the control group, which was due to increased (P = 0.045) proportion of total short- and medium-chain FA (C4 to C14). Feed intake, digestibility of crude protein and fiber, and total n-6, n-3, mono-unsaturated FA, poly-unsaturated FA, and long-chain FA (C18 to C24) proportions were similar between the groups. This study suggests that feeding of EFP at 20 g/kg DM intake increases milk production and decreases methane production and intensity without impacting health of buffaloes and FA profiles of milk. This is a win–win situation for sustainable and cleaner buffalo production by improving milk production and decreasing environmental burdens of greenhouse gas emission and EFP residue disposal problems.

Food contamination by aflatoxin B1 (AFB1), produced by mycotoxigenic strains of Aspergillus spp., causes severe medical and economic implications. Essential oils (EOs) are mixtures of eco-friendly natural volatile substances. Their ability to inhibit fungal growth has been investigated, while no data are available about their efficacy in inhibition of AFB1 biosynthesis. This study investigates the efficacy of five different citrus EOs to inhibit the growth and AFB1 synthesis of A. flavus through in vitro tests for a future application in food matrices. AFB1 detection was carried out by LC-ESI-TQD analytical approach. Lemon (Citrus limon (L.) Burm. f.), bergamot (Citrus bergamia Risso), and bitter orange (Citrus aurantium L.) EOs were the most effective causing a 97.88%, 97.04%, and 96.43% reduction in mycelial growth, respectively. Sweet orange and mandarin EOs showed the lowest percentage of mycelial growth reduction. Citrus EOs showed different capacity of AFB1 inhibition (lemon > bitter orange > bergamot > sweet orange > mandarin). Our results showed a dose-dependent antifungal activity of lemon, bitter orange, and bergamot EOs which at 2% (v/v) inhibited both mycelium growth and AFB1 genesis of A. flavus. Our results show that EOs’ use can be a pivotal key to recovery and reuse of citrus fruit wastes and to be used as eco-friendly fungicides for improvement of food safety. The use of EOs obtained at low cost from the residues of citric industry presents an interesting option for improving the profitability of the agriculture.

More than 1 million tons of fresh organic wastes is produced in the Souss-Massa region in Morocco. Tomato organic residues represent more than 25% of the total organic wastes and are deposited in uncontrolled landfills. Thus, composting can represent a valuable and pertinent solution to this environmental problem. The objectives of this experiment are to identify the potential functional groups responsible for compost phytotoxicity and to determine the optimum initial carbon to nitrogen ratio (C/N) for maximum recovery of tomato residues. The experiment consisted of the variation of the initial C/N ratios (25, 30, 35, and 40) using mixtures of different raw materials (tomato residues, melon residues, olive mill pomace, and sheep manure). Physicochemical parameters (pH, electrical conductivity, C/N ratio, and humic acid/fulvic acid ratio) were determined and spectroscopic analyses (UV-vis and NMR-¹³C) were performed during the composting process along with quality parameters (germination and phytotoxicity tests) at the end. The results showed that the compost with the initial C/N ratio of 35 is the most humified with the least phytotoxic effect. The germination and phytotoxicity tests were negatively correlated with the methoxyl/N-alkyl-C ratio and O-alkyl-C. These two functional groups are probably the origin of phytotoxicity expression in compost quality tests. Thus, a simple and precise quality test could be performed to evaluate directly the phytotoxicity and maturity of compost.