A study was undertaken to determine the effects of a strain of Arthrobacter sp., a Plant Growth-Promoting Bacteria (PGPB), on plant phenology and qualitative composition of Opuntia ficus-indica (L.) Mill. fruits and cladodes. The strain was inoculated in soil, and its effects on cactus pear plants were detected and compared to nontreated plants. Compared to the latter, the treatment with bacteria promoted an earlier plant sprouting (2 months before the control) and fruitification, ameliorating fruit quality (i.e., improved fresh and dry weight: + 24% and + 26%, respectively, increased total solid content by 30% and polyphenols concentrations by 22%). The quality and quantity of monosaccharides of cladodes were also increased by Arthrobacter sp. with a positive effect on their nutraceutical value. In summer, the mean values of xylose, arabinose, and mannose were significantly higher in treated compared to not treated plants (+ 3.54; + 7.04; + 4.76 mg/kg d.w. respectively). A similar trend was observed in autumn, when the cladodes of inoculated plants had higher contents, i.e., 33% xylose, 65% arabinose, and 40% mannose, respect to the controls. In conclusion, Arthrobacter sp. plays a role in the improvement of nutritional and nutraceutical properties of cactus pear plants due to its capabilities to promote plant growth. Therefore, these results open new perspectives in PGPB application in the agro-farming system as alternative strategy to improve cactus pear growth, yield, and cladodes quality, being the latter the main by-product to be utilized for additional industrial uses.

The by-products of green coffee processing are rich in compounds that can be recycled for their possible use in the production of beverages, fertilizers and weed control in production areas. The objective of this work was to identify the organic and inorganic bioactive compounds of green coffee and the coffee by-products related to the production of origin, such as dried cascara (skin-pulp), parchment and silverskin (unroasted), in order to investigate the role their biomolecules may have in reuse through practices and local knowledge, not yet valued. The metabolomic profile by HPLC-ESI-HRMS of the aqueous extract of the dried cascara highlighted 93 non-volatile molecules, the highest number reported for dried cascara. They belong to groups of organic acids (12), alkaloids (5), sugars (5), fatty acids (2), diglycerides (1), amino acids (18), phospholipids (7), vitamins (5), phenolic acids (11), flavonoids (8), chlorogenic acids (17), flavones (1) and terpenes (1). For the first time, we report the use of direct analysis in real-time mass spectrometry (DART-MS) for the identification of metabolites in aqueous extracts of dried cascara, parchment, silverskin and green coffee. The DART analysis mainly showed the presence of caffeine and chlorogenic acids in all the extracts; additionally, sugar adducts and antioxidant compounds such as polyphenols were detected. The mineral content (K, Ca, P, S, Mg and Cl) by EDS spectrometry in the by-products and green coffee showed a relatively high content of K in the dried cascara and green coffee, while Ca was detected in double quantity in the silverskin. These metabolomic and mineral profile data allow enhancement of the link between the quality of green coffee and its by-products and the traditional local practices in the crop-growing area. This consolidates the community’s experience in reusing by-products, thereby minimizing the impact on the environment and generating additional income for coffee growers’ work, in accordance with the principles of circular economy and bioeconomy.

Bio-fertilizers could be a possible solution to help manage bio-waste problems and to maintain soil health conditions, especially in organic farms. Pruning of cactus pear produces from 6 to 10 tons/yearly of cladodes per hectare in specialized Italian orchards, which represents waste and a cost for disposal to farmers. Therefore, the aim of the work was to investigate the effects on soil physical properties, microflora activity, and basil plant growth of powdered pruning waste from cactus pear incorporated in the soil (10%, 20%, 30% 40% w/w). Moreover, we studied a dynamic composting process from fresh cladodes to produce stabilized end-products at the farm level. Our studies demonstrated that holding water ability and bulk density of soil were ameliorated by supplementing dried cladodes. Thus, gravitational and gravimetric water was positively correlated with the increase of added dried cladode in the soil (0.1% and 6.2 g H₂O ± 0.3 in samples of 40% mixed soil versus 68% and 3.3 g H₂O ± 0.3 in control). Furthermore, bulk density was reduced limiting soil compaction. Preliminary results on microbial activity suggested a possible selection/inhibition of some bacterial strains correlated with the increment of dry cladode supplementation. The basil plants grown in 20% mixed soil showed an increased biomass when compared to the control (+ 21%). Finally, raw cladode proved to be an excellent substrate for aerobic fermentation providing a final product of good quality and high moisture content (65%). These results are particularly relevant in organic agriculture where bio-fertilizers are recommended as economical, eco-friendly solution accessible also to marginal and small farms.

The coffee cherry processing produces various waste products, such as coffee husks, which are a valuable source of pectin and phenolic acids that can be used as high-value biomolecules in human and animal food, cosmetics, and pharmaceutical production chains. This study aims to optimize the eco-friendly extraction of polysaccharides, as pectin, and phenolic compounds from coffee peel using response surface methodology (RSM). This model was used to evaluate the extraction variables (temperature, time, pH, ionic strength, ultrasonic frequency, particle size, and solid/liquid ratio in water) to identify the critical factors. All responses were fitted to the RSM model, which revealed high estimation capabilities. Ionic strength and temperature were found to be critical process variables for pectin extraction, while the main factors responsible for phenolic extraction were ultrasonic frequency, pH, and solid/liquid ratio. Therefore, the operating conditions to optimize the extraction of both pectin and phenolic compounds were 80 °C, ultrasonic frequency 60 kHz, solid/liquid ratio 1:20, using pH 2 or 12 in the case of pectin or polyphenols, respectively. Direct Analysis in Real Time Mass Spectrometry (DART-MS) and Fourier-Transform Infrared Spectroscopy–Attenuated Total Reflectance (FTIR-ATR) analyses were performed to evaluate the chemical profile of the extracts and pectin. The recycling of coffee husk waste into bioproducts in view of the circular economy contributes to minimizing the impact on the environment and to generating additional income for coffee growers.

Aim: Triticale is a well adaptable crop, tolerant of disease and abiotic stresses, and able to grow with good yields even in poor soil, thus representing a good choice to develop a new industrial agri-chain in Italy in a sustainability contest, to cope with its soil problems due to incoming desertification. Methods: Two triticale elite lines were grown in marginal lands in controlled field experiments. The lines were harvested at two different development stages, namely green mass and seeds, and suitable standard protocols were applied to test their potential to produce bioethanol in line with the emerging bioenergy processes. Results: The protocols applied were able to obtain bioethanol with a good yield from both feedstocks. In particular, very efficient fermentation kinetics was observed using seed feedstock, with a sharp curve between 15 h and 24 h, reaching 84% of the total alcohol obtained (final time 72 h). Conclusions: Therefore, the results of this research point to new sustainable potential for industrial applications of triticale crops in Italy. Furthermore, the high activity of the endogenous amylolytic enzymes, mainly α-amylase, and the high starch content suggest the potential use of triticale in other industrial applications, like the brewing industry.

In specialized orchards, approximately 6–10 tons/hectare of cactus pear pruning waste and 60 million tons of spent coffee grounds are estimated to be produced each year worldwide. Composting is a process that produces stable organic matter useful in agriculture. The aim of this work was to explore the potential of Opuntia ficus-indica (OFI) cladodes and spent coffee ground (SCG) mixtures for compost production and to assess their benefits for agricultural applications. Three composting campaigns were carried out using rotating composters. Feedstock for these campaigns was formulated with different ratios of OFI and SCGs, and the compost obtained were characterized by their chemical and physical proprieties. To assess these composts, basil was grown in plots using growing substrate as a blank and comparing it with substrate mixed with 10% of each compost. All plants sprouted and grew up. While no significant differences were detected in polyphenol content among the grown plants, the yields with compost at OFI–SCG (3.3:1) were differentiated for longer shoots and there was greater biomass compared to the control. Compost obtained from cladode mixed with spent coffee grounds proved to be a good soil improver with the characteristics of being able to ameliorate soil fertility and plant growth.