Search

BACKGROUND Pest control in post-harvest food storage represents a great challenge in the sustainable prevention of food losses, and insecticide-treated netting may represent a valid alternative to traditional practices such as the direct application of insecticides. In our work, the efficacy of a permethrin-incorporated net, in combination with polypropylene or jute sacking, was tested for the control of Sitophilus oryzae. Contamination of maize grain by permethrin from the treated netting was also evaluated. RESULTS A 98% control of S. oryzae was achieved using permethrin-treated netting. Both jute and polypropylene acted as additional barriers, increasing efficacy to 100%. The results also showed the contamination of maize kernel by permethrin released from the treated netting. The concentration of residues in maize kernels increased with increasing temperature; however, use of jute or polypropylene significantly reduced (by 87% to 97%) the concentration of residues transferred to maize kernels. CONCLUSIONS Permethrin-treated netting provided a high level of efficacy in the post-harvest protection of maize. Several factors influenced permethrin residue concentrations in grains when treated nets are used. Therefore, solutions should be found to prevent contamination of food stored in the bags that are treated with insecticides. © 2017 Society of Chemical Industry

Several foods on the market, such as yogurt and fermented milk, include mixtures of prebiotics and probiotic microorganisms effective in promoting the proliferation and equilibrium of intestinal bacteria, thus improving gut health. Particularly, researchers and the public have shown increasing interest in the combination of probiotics with natural substances that promote health or that can act as substrates to promote bacterial growth. The aim of this study is to evaluate the effects of different extracts of Aloe barbadensis and Aloe arborescens in fermented milk, taking into account boththe prebiotic effect of aloe polysaccharides and the antimicrobial activity of several secondary metabolites. The results demonstrate a beneficial effect of 5% aloe inner gel on Lactobacillus growth and confirm the antimicrobial activity of the phenolic compounds peculiar of green rind extracts.

The phytochemical profile of Aloe barbadensis Mill. and Aloe arborescens Mill. was investigated using colorimetric assays, triple quadrupole and time-of-flight mass spectrometry, focusing on phenolic secondary metabolites in the different leaf portions. Hydroxycinnamic acids, several characteristic anthrones and chromones, the phenolic dimer feralolide and flavonoids such as flavones and isoflavones were identified. The stable radical DPPH test and the ORAC assay were then used to determine the in vitro radical scavenging. The outer green rind was the most active, while the inner parenchyma was much less effective. The 5-methylchromones aloesin, aloeresin A and aloesone were the most active among the pure secondary metabolites tested. The results suggest that several compounds are likely to contribute to the overall radical scavenging activity, and indicate that leaf portion must be taken into account when the plant is used for its antioxidant properties.

Surveys carried out in some villages of Democratic Republic of the Congo showed that insect pests are a major cause of food loss for rural populations. Cereal grains are often compromised by pests in the field and during storage. Among cereals cultivated for family consumption in these areas of Africa, mainly maize and rice are both seriously infested by Coleopteran pests belonging to the genus Sitophilus. Any approach currently adopted to solve this problem, as the manual removal of visible insects, is often inadequate or insufficient. Due to the limited availability of chemical insecticides and their high price in these countries, our aim is to study a simple and cheap way to protect grain after harvest. The technology derives from anti-malaria mosquito nets, also known as insecticide treated nets (ITNs) or bednets, modified for the new purpose. Nets consist in fine-mesh polyester coated with permethrin (2.0%), a synthetic second generation pyrethroid that gives repellent and insecticide effect, while ensuring a high human safety. The idea is to use these nets to wrap jute bags or other containers in which grain is commonly stored in poor countries. Preliminary bioassays with adults of Sitophilus oryzae showed that knock-down values for 50% and 95% of exposed insects (KD50 and KD95, respectively) were equal to 4.8 and 9.5 minutes. We are currently carrying out further in vivo bioassays (in Italy) and field studies (in Congo) to test the efficacy of the treated net. The coating of structures for grain preservation could be a viable sustainable strategy for limiting food losses in countries that lack resources and technologies for pest control.

Entomophagy is a common practice in many African countries, where insects often represent a significant proportion of protein in the diet of many rural populations. Studies about the possibility of easy rearing of edible insects are presented, both for human and animal consumption.

Food is one of the issue that particularly engage us, especially in the more developed countries; we have only to look at how much space is dedicated to it in newspapers, magazines, and radio and television broadcasts. It has thus been chosen as the theme for the Universal Exposition of 2015 - Expo 2015 - in Milan. There has of course been growing awareness of the links between climate change, the pressure on natural resources, dem ographic growth, the depopulation of rural areas, some populations' access to diets that are richer in animal protein, and how all these elements demand a thorough overhaul of the systems for agricultural production, both in developing countries and in developed countries.

Il progetto è stato condotto in tre aree differenti dal punto di vista geografico e socio-ambientale (Italia, India e Repubblica Democratica del Congo), al fine di individuare modalità appropriate per garantire produzioni agricole adeguate alle esigenze nutrizionali e allo sviluppo locale nel rispetto dell'ambiente.