Date Fruit Processing Waste and Approaches to Its Valorization: A Review.
In the Middle East and North Africa, dates are a traditional and economically valuable crop, playing an essential role in people's daily diets. Date fruit production and related processing industry generate a large quantity of waste; for illustration, the date juicing industry produces roughly 17-28% Date press cake (DPC), which is mainly discarded in open lands and drains. Considering the generation volume and the nutrient content of DPC, this organic by-product stream can be valorized through the production of a wide range of products with a great market appeal, such as volatile fatty acids, activated carbon, organic acids, etc. To provide an insight into the feasibility of the application DPC as a green precursor for various chemical and biological processes, the chemical and nutritional composition of dates and DPC, an overview of the date processing industries, and common practices conducted for DPC valorization addressed and thoroughly discussed, in this review. https://doi.org/10.1016/j.biortech.2021.125625
Experimental and Theoretical Studies on Extract of Date Palm Seed as a Green Anti-Corrosion Agent in Hydrochloric Acid Solution.
Extracts from plant materials have great potential as alternatives to inorganic corrosion inhibitors, which typically have harmful consequences. Experimental and theoretical methodologies studied the effectiveness of agricultural waste, namely, date palm seed extract as a green anti-corrosive agent in 0.5 M hydrochloric acid. Experimental results showed that immersion time and temperature are closely related to the effectivity of date palm seed as a corrosion inhibitor. The inhibition efficiency reduced from 95% to 91% at 1400 ppm when the immersion time was increased from 72 h to 168 h. The experimental results also indicated that the inhibition efficiency decreased as the temperature increased. The presence of a protective layer of organic matter was corroborated by scanning electron microscopy. The adsorption studies indicated that date palm seed obeyed Langmuir adsorption isotherm on the carbon steel surface, and Gibbs free energy values were in the range of -33.45 to -38.41 kJ·mol-1. These results suggested that the date palm seed molecules interacted with the carbon steel surface through mixture adsorption. Theoretical calculations using density functional theory showed that the capability to donate and accept electrons between the alloy surface and the date palm seed inhibitor molecules is critical for adsorption effectiveness. The HOMO and LUMO result indicated that the carboxyl (COOH) group and C=C bond were the most active sites for the electron donation-acceptance type of interaction and most auxiliary to the adsorption process over the Fe surface. https://doi.org/10.3390/molecules26123535
Pyrolysis of Almond (Prunus amygdalus) Shells: Kinetic Analysis, Modelling, Energy Assessment and Technical Feasibility Studies.
The aim of this work was to study the thermogravimetric analysis through the pyrolysis of almond (Prunus amygdalus) shells for evaluating its potential for bioenergy at different heating rates (10, 25, and 50 K min-1). The activation energy values for the process were of the range of 153.0, 152.02, and 152.73 kJ mol-1 as calculated by Kissenger-Akahira-Sunrose (KAS), Ozawa-Flynn-Wall (OFW) and Starink models respectively. The change in the Gibbs free energy was ~181 kJ mol-1. Diffusion-based reaction, followed by the chemical reaction mechanism,was dominant thermal degradation as envisaged by the Coats-Redfern method. The validation of the experiments was accomplished through the artificial neural network, reiterating its further usage in any conversional studies of biomass. A difference of < 10 kJ mol-1 between the values of activation energy and enthalpy of the degradation reaction indicated favourable product formation. The results offer potential application of almond shells for energy production through pyrolysis. https://doi.org/10.1016/j.biortech.2021.125466
Healthier and more sustainable diets: What changes are needed in high‐income countries?.
Debate persists around the food production and dietary changes needed to improve sustainability of our global food system. We reviewed 29 studies in high-income countries that used various methodologies to define a healthier, more sustainable diet. Diets aligned with dietary guidelines, containing less meat and higher amounts of plant-derived foods (vegetables, pulses [beans/lentils], fruit, wholegrains, nuts, seeds) would likely offer environmental benefits (~20–50% lower greenhouse gas emissions [GHGE] and land use) and improve population health, although may not reduce water footprint. Changes in consumption of milk products and eggs were inconsistent in optimisation studies, perhaps reflecting trade-offs between their nutrient contribution and environmental impact. Foods high in fat, salt and/or sugar, and beverages (e.g. tea, coffee and fruit juices) contributed substantially to environmental footprints in some studies. Vegetarian and vegan diets may deliver larger environmental benefits, but are unlikely to be widely adopted, and may reduce intakes and/or bioavailability of some essential nutrients (e.g. iron, zinc, iodine and B12). We recommend adherence to existing government dietary guidelines as a more realistic goal to improve environmental (e.g. 30% lower GHGE in the UK) and health impacts of diets, recognising that adherence is currently relatively poor. Wider considerations include: context-specific nutritional, health, cost and cultural needs; need for public engagement to understand barriers/motivators; better understanding of the wider implications and trade-offs linked to dietary and food system changes and how these can be managed, so that benefits in high-income countries do not come at the expense of greater ‘outsourced’ environmental impacts in other regions. https://doi.org/10.1111/nbu.12518
Sugarcane/peanut intercropping system improves physicochemical properties by changing N and P cycling and organic matter turnover in root zone soil
Background: The sugarcane/peanut intercropping system is a specific and efficient cropping pattern in South China. Intercropping systems change the bacterial diversity of soils and decrease disease rates. It can not only utilized light, heat, water and land resources efficiently, but also increased yield and economic benefits of farmers.
Methods: We determined soil nutrients, enzymes and microbes in sugarcane/peanut intercropping system, and analyzed relevance of the soil physicochemical properties and the genes involved in N and P cycling and organic matter turnover by metagenome sequencing.
Results: The results showed that sugarcane/peanut intercropping significantly boosted the content of total nitrogen, available phosphorus, total potassium, organic matter, pH value and bacteria and enhanced the activity of acid phosphatase compared to monocropping. Especially the content of available nitrogen, available phosphorus and organic matter increased significantly by 20.1%, 65.3% and 56.0% in root zone soil of IP2 treatment than monocropping treatment. The content of available potassium and microbial biomass carbon, as well as the activity of catalase, sucrase and protease, significantly decreased in intercropping root zone soil. Intercropping resulted in a significant increase by 7.8%, 16.2% and 23.0% in IS, IP1 and IP2, respectively, of the acid phosphatase content relative to MS. Metagenomic analysis showed that the pathways involved in carbohydrate and amino acid metabolism were dominant and more abundant in intercropping than in monocropping. Moreover, the relative abundances of genes related to N cycling (glnA, GLUD1_2, nirK), P cycling (phoR, phoB) and organic matter turnover (PRDX2_4) were higher in the intercropping soil than in the monocropping soil. The relative abundance of GLUD1_2 and phoR were 25.5% and 13.8% higher in the IP2 treatment respectively,and bgIX was higher in IS treatment compared to the monocropping treatment. Genes that were significantly related to phosphorus metabolism and nitrogen metabolism (TREH, katE, gudB) were more abundant in intercropping than in monocropping.
Conclusion: The results of this study indicate that the intercropping system changed the numbers of microbes as well as enzymes activities, and subsequently regulate genes involved in N cycling, P cycling and organic matter turnover. Finally, it leads to the increase of nutrients in root zone soil and improved the soil environment.
Nutshells as Efficient Biosorbents to Remove Cadmium, Lead, and Mercury from Contaminated Solutions
The release of potentially toxic elements into the environment, and their effects on aquatic ecosystems still present a real threat. To avoid such contamination, the use of biological sorbents as an alternative to conventional and expensive water remediation techniques has been proposed. The present study evaluated the potential of 0.5 g L-1 of peanut, hazelnut, pistachio, walnut, and almond shells to remove the requisite concentrations of cadmium (Cd), lead (Pb), and mercury (Hg) from contaminated water. Hazelnut shells were identified as the sorbent with the highest potential and were evaluated in mono- and multi-contaminated mineral water. The influence of sorbent-intrinsic and solution-intrinsic characteristics were assessed. Differences among sorbents were attributed to varying percentages of their main components: cellulose, hemicellulose, and lignin. Matrix complexity increase caused a decrease in Cd removal, presumably due to the diminution in electrostatic interaction, and complexation with anions such as Cl-. When simultaneously present in the solution, contaminants competed, with Pb showing higher affinity to the sorbent than Hg. High efficiencies (>90%) obtained for hazelnut shells for all elements in ultrapure water and for Pb and Hg in mineral water) reveals the high potential of this low-cost and abundant waste for use in the remediation of contaminated waters (circular economy).
Evaluation of pruning wound protection products for the management of almond canker diseases in California
Almond trunk and branch canker diseases constitute a major cause of tree mortality in California. Numerous fungal pathogens have been associated with these canker diseases and pruning wounds act as major infection courts. Prior to this study, there were no products registered in California for the management of these diseases. In this study, fungicidal products including synthetic chemistries, biocontrols, paint and a sealant were evaluated for preventing fungal pathogen infection via pruning wounds. In four field trials conducted over two dormant seasons, sixteen pruning wound treatments were tested using hand-held spray applications, against five almond canker pathogens, namely Botryosphaeria dothidea, Neofusicoccum parvum, Cytospora sorbicola, Ceratocystis destructans, and Eutypa lata. The fungicide thiophanate-methyl (Topsin M) provided 82% overall disease prevention against four fungal pathogens. The biological control agent, Trichoderma atroviride SC1 (Vintec), tested at three application rates, resulted in 90 to 93% protection of pruning wounds in field trials, and for individual pathogens ranged from 81-100% protection for the three rates. At the time of this publication, Vintec is being considered for registration as a biological control product for the prevention of almond canker diseases, while Topsin M is recommended to growers for the prevention of almond canker diseases. This research indicates that effective protection of pruning wounds from infection by almond canker pathogens can be achieved with a one-time spray application of thiophanate-methyl or the biocontrol, T. atroviride SC1 (recommended 2 g/liter) after pruning.
Future-proof and sustainable healthy diets based on current eating patterns in the Netherlands.
Background: To keep global warming <1.5°C as recommended by the Intergovernmental Panel on Climate Change (IPCC), eating patterns must change. However, future diets should be modeled at a national level and respect cultural acceptability. Objectives: We aimed to identify diets among Dutch adults satisfying nutritional and selected environmental requirements while deviating minimally from the baseline diet among Dutch adults. Methods: We calculated per capita food system greenhouse gas emission (GHGE) targets derived from the IPCC 1.5-degree assessment study. Using individual adult dietary intake from the National Food Consumption Survey in the Netherlands (2007-2010) to form a baseline, we used quadratic optimization to generate diets that followed the baseline Dutch diet as closely as possible, while satisfying nutritional goals and remaining below GHGE targets. We considered 12 scenarios in which we varied GHGE targets [2050: 1.11 kg of carbon dioxide equivalent (kg CO2-eq) per person per day (pppd); 2030: 2.04 kg CO2-eq pppd; less strict 2030: 2.5 kg CO2-eq pppd; no target], modeled eating patterns (food-based dietary guidelines; flexitarian; pescatarian; lacto-ovo-vegetarian; vegan), and conducted exploratory analyses (food diversity; acceptability; food chain interdependency). Results: Optimized solutions for 2030 required major decreases (<33% of baseline values) in consumption of beef, pork, cheese, snacks, and butter and increased consumption (>150% of baseline values) of legumes, fish and shellfish, peanuts, tree nuts, vegetables, soy foods, and soy drink. Eight food groups were within 33%-150% of the baseline diet among Dutch adults. The optimized solution complying to the lowest GHGE target (2050) lacked food diversity, and the (lacto-ovo) vegetarian and vegan optimized diets were prone to nutritional inadequacies. Conclusions: Within Dutch eating habits, satisfying optimization constraints required a shift away from beef, cheese, butter, and snacks toward plant-based foods and fish and shellfish, questioning acceptability. Satisfying 2050 food system GHGE targets will require research in consumer preferences and breakthrough innovations in food production and processing.
Isolation and characterization of micro and nanocrystalline cellulose fibers from the walnut shell, corncob and sugarcane bagasse.
The present study aims to extract and characterize the microcrystalline cellulose (MCC) present in different agro-industrial wastes such as walnut shells, corncob, and sugarcane bagasse. Moreover, it is also the aim of this study to convert MCCs to nanocrystalline cellulose fiber (NCCF), to demonstrate the difference in morphological, structural, thermal, and chemical natures. Corncob cellulose was observed to possess a loosely bounded linear bundle structure. Nanocrystalline cellulose fiber yield from walnut shell and sugarcane bagasse cellulose were higher than corncob cellulose. The thermal stability of cellulose was noted to be high for walnut shell NCCF. Nanocrystalline cellulose fiber of corncob and sugarcane bagasse was estimated to have a low thermal degradation temperature. All the MCCs and NCCFs produced from investigated cellulose sources were found to have type I cellulose. Functional group compositions of cellulose were observed to be intact for converted agro-based NCCF's.
Development of an antioxidant formula based on peanut by‐products and effects on sensory properties and aroma stability of fortified peanut snacks during storage.
Background: An antioxidant formula based on peanut skins and hulls, was developed and characterized for total and single polyphenols, and antioxidant power, considering the contribution provided by each peanut by-product. Then, it was evaluated for its effect on sensory properties and aroma stability of peanut bars over a 100-day period. To this purpose, snacks fortified and not with the natural additive were experimentally produced. Results: Peanut hulls contributed to a greater extent than skins to boost the content of bioactives and the antioxidnt activity of the antioxidant formula, which was marked by a phenol content of (~807 mg GAE g-1 ) and a DPPH activity similar to that of butylated hydroxytoluene (respectively, 85.96% and 89.30%). From a sensory perspective, the incorporation of the formulation in snacks caused only a slightly stronger perception of astringent and bitter notes. Pyrazines, phenol, furan, and pyrrole derivatives outlined the aroma of snacks, being more abundant in fortified than conventional samples. Such volatiles faded over storage with different trends in examined products. For example, the sum of 2,5-dimethylpyrazine, 2-ethylpyrazine and 2,3-dimethylpyrazine was 9.49 and 8.87 ppm at day 15; 5.57 and 7.16 ppm at day 45; 5.03 and 4.65 ppm at day 100, respectively in fortified and conventional snacks; hydroxymethylfurfural decreased constantly over storage in conventional samples, and only after day 45 in fortified bars. Conclusion: Overall, the antioxidant formulation did not compromise the sensory desirability of peanut snacks and induced a preservative effect on their aroma, especially during the first 15 days of storage.