Pellet Production from Pruning and Alternative Forest Biomass: A Review of the Most Recent Research Findings.

Typically, coniferous sawdust from debarked stems is used to make pellets. Given the high lignin content, which ensures strong binding and high calorific values, this feedstock provides the best quality available. However, finding alternative feedstocks for pellet production is crucial if small-scale pellet production is to be developed and used to support the economy and energy independence of rural communities. These communities have to be able to create pellets devoid of additives and without biomass pre-processing so that the feedstock price remains low. The features of pellets made from other sources of forest biomass, such as different types of waste, broadleaf species, and pruning biomass, have attracted some attention in this context. This review sought to provide an overview of the most recent (2019-2023) knowledge on the subject and to bring into consideration potential feedstocks for the growth of small-scale pellet production. Findings from the literature show that poor bulk density and mechanical durability are the most frequent issues when making pellets from different feedstocks. All of the tested alternative biomass typologies have these shortcomings, which are also a result of the use of low-performance pelletizers in small-scale production, preventing the achievement of adequate mechanical qualities. Pellets made from pruning biomass, coniferous residues, and wood from short-rotation coppice plants all have significant flaws in terms of ash content and, in some cases, nitrogen, sulfur, and chlorine content as well. All things considered, research suggests that broadleaf wood from beech and oak trees, collected through routine forest management activities, makes the best feasible feedstock for small-scale pellet production. Despite having poor mechanical qualities, these feedstocks can provide pellets with a low ash level. High ash content is a significant disadvantage when considering pellet manufacture and use on a small scale since it can significantly raise maintenance costs, compromising the supply chain's ability to operate cost-effectively. Pellets with low bulk density and low mechanical durability can be successfully used in a small-scale supply chain with the advantages of reducing travel distance from the production site and storage time.

Opuntia spp.: An Overview of the Bioactive Profile and Food Applications of This Versatile Crop Adapted to Arid Lands.

Opuntia spp. are crops well adapted to adverse environments and have great economic potential. Their constituents, including fruits, cladodes, and flowers, have a high nutritional value and are rich in value-added compounds. Cladodes have an appreciable content in dietary fiber, as well as bioactive compounds such as kaempferol, quercetin, and isorhamnetin. Fruits are a major source of bioactive compounds such as phenolic acids and vitamin C. The seeds are mainly composed of unsaturated fatty acids and vitamin E. The flowers are also rich in phenolic compounds. Therefore, in addition to their traditional uses, the different plant fractions can be processed to meet multiple applications in the food industry. Several bakery products have been developed with the incorporation of cladode flour. Pectin and mucilage obtained from cladodes can act as edible films and coatings. Fruits, fruit extracts, and fruit by-products have been mixed into food products, increasing their antioxidant capacity and extending their shelf life. Betalains, obtained from fruits, can be used as food colorants and demonstrate promising applications as a sensor in food packaging. This work reviews the most valuable components of the different fractions of this plant and emphasizes its most recent food applications, demonstrating its outstanding value.

Factors Influencing Italian Consumers' Willingness to Pay for Eggs Enriched with Omega-3-Fatty Acids.

This paper focused on eggs enriched with omega-3-fatty acids with the aim of understanding if functional eggs were of interest to Italian consumers, and analyzing which characteristics of table egg quality, consumers' attitudes and socio-demographic characteristics affect the consumers' willingness to pay (WTP) a premium price for eggs enriched with omega-3-fatty acids. We performed an online survey on 312 Italian consumers. The analysis was based on the Tobit regression model. The findings showed that unmarried females were more willing to pay a premium price for functional eggs than male consumers. Furthermore, the probability of showing a higher WTP for functional eggs increased among consumers reporting a higher income. Moreover, the WTP for functional eggs increased with the growing importance that people attributed to items such as the size of eggs, rearing type, feed given to chickens, and the provenience and brand of eggs. These results suggested that consumers need to have clear information about functional eggs. As expected, WTP for functional eggs decreased with increasing neophobia and food techno-neophobia factors. In conclusion, the findings showed an interesting potential for eggs enriched with omega-3-fatty acids, which seems to be a product with high possibility to be greatly appreciated on the market, especially if accompanied by a good, informative campaign for increasing people's knowledge level.

Pruning harvesting with modular towed chipper: Little effect of the machine setting and configuration on performance despite strong impact on wood chip quality.

Pruning residues can have a high quality as feedstock for energy purposes and are largely available in Europe. However, it is still an untapped resource. Such scarce use is due to the need to optimize their supply chain in term of collection machines and the associate cost of collection. A modular chipper (prototype PC50) for pruning harvest was developed. Such prototype is adaptable to various harvesting logistics and may produce a higher quality woodchip compared with the one produced by shredders available in the market. In this work, we tested the performance and quality of the product delivered by the prototype PC50 in various conditions and plant species, after a modulation of the machine settings (counter-rotating toothed rollers [CRR] speed), loading systems ([LS], either big bag or container), and knife types ([KT], either discontinuous hoe shaped knives or continuous helicoidal knives). To take into account of the covariates in the experiment (Cropping season and plant species), LSmeans were computed to have an unbiased estimate of the treatments means. The modulation of LS and KT scarcely affected the performance of the machine. In particular, the choice of the KT affected the field efficiency when the LS was a Tilting box but not a Big Bag. Whereas the continuous knife resulted in a 97% higher material capacity compared to hoe shape knives, the last of which the amount of short sized (<16 mm) fractions compared to helicoidal knives. No role of the CCR was found on the machine performance, but increasing CRR speed reduced the chip apparent bulk density and the fraction chips with a size <8 mm.

Opuntia ficus-indica as an Ingredient in New Functional Pasta: Consumer Preferences in Italy.

Opuntia ficus-indica is a source of minerals and vitamins and has recently been used as ingredient to make a new functional variety of pasta. Italy was the first country in the world to produce pasta and is also the second largest producer of Opuntia in the world. According to an Italian sample, this study considers the main factors that could influence consumers when choosing functional pasta (featuring Opuntia) and characterizes distinct hypothetical consumer segments in terms of their food habits, pasta choices, and perceptions toward functional pasta featuring Opuntia. Data were collected using a web-based survey and with 328 respondents. Factor analysis (FA) with orthogonal rotation (varimax) was used to simplify the observed variables and hierarchical cluster analysis was performed with the FA results. Seven clusters were identified and the main results show that the level of education plays an important role in the perception of functional pasta. In fact, the perceptions of well-educated people differed from poorly-educated people. Moreover, the results showed significant respondent interest regarding health benefits and the nutritional and environmental aspects of functional pasta, which should encourage people's acceptance and consumption of this new functional food. In addition, the respondent preferences reflect a value of experience towards the pasta, i.e., the belief of cooking typical Italian pasta. This means that Opuntia used for the production of functional pasta should maintain the organoleptic and physical properties of durum wheat-based pasta. In addition, respondent preferences for pasta featuring Opuntia could also be driven by its price.

Technology alternatives for tapping the pruning residue resource.

Four commercial harvesters were compared with respect to recovery of pruning residues for energy conversion. These harvesters were tested side-by-side on 17 test fields, totaling 15 ha. The test fields consisted of vineyards and apple and pear orchards. The residue yield was between 0.7 and 9 green tonne per hectare, at a moisture content from 37% to 48%. Yield was highest for the orchards, and lowest for vineyards. Harvesters collected the residues and moved them to the roadside at a cost of between 11 and 60€ per green tonne, depending on field conditions and technology choice. Single-pass harvesting was the cheapest, especially if applied through a dedicated tractor and a towed unit with a large integral container. Two-pass harvesting was the most flexible, but also the most expensive: it should be favored only when space, weather or other management constraints limit the application of the other systems.

Nitrogen concentration estimation in tomato leaves by VIS-NIR non-destructive spectroscopy.

Nitrogen concentration in plants is normally determined by expensive and time consuming chemical analyses. As an alternative, chlorophyll meter readings and N-NO(3) concentration determination in petiole sap were proposed, but these assays are not always satisfactory. Spectral reflectance values of tomato leaves obtained by visible-near infrared spectrophotometry are reported to be a powerful tool for the diagnosis of plant nutritional status. The aim of the study was to evaluate the possibility and the accuracy of the estimation of tomato leaf nitrogen concentration performed through a rapid, portable and non-destructive system, in comparison with chemical standard analyses, chlorophyll meter readings and N-NO(3) concentration in petiole sap. Mean reflectance leaf values were compared to each reference chemical value by partial least squares chemometric multivariate methods. The correlation between predicted values from spectral reflectance analysis and the observed chemical values showed in the independent test highly significant correlation coefficient (r = 0.94). The utilization of the proposed system, increasing efficiency, allows better knowledge of nutritional status of tomato plants, with more detailed and sharp information and on wider areas. More detailed information both in space and time is an essential tool to increase and stabilize crop quality levels and to optimize the nutrient use efficiency.