Valorisation of Agri-Food Waste for Bioactive Compounds: Recent Trends and Future Sustainable Challenges.

Worldwide, a massive amount of agriculture and food waste is a major threat to the environment, the economy and public health. However, these wastes are important sources of phytochemicals (bioactive), such as polyphenols, carotenoids, carnitine, coenzymes, essential oils and tocopherols, which have antioxidant, antimicrobial and anticarcinogenic properties. Hence, it represents a promising opportunity for the food, agriculture, cosmetics, textiles, energy and pharmaceutical industries to develop cost effective strategies. The value of agri-food wastes has been extracted from various valuable bioactive compounds such as polyphenols, dietary fibre, proteins, lipids, vitamins, carotenoids, organic acids, essential oils and minerals, some of which are found in greater quantities in the discarded parts than in the parts accepted by the market used for different industrial sectors. The value of agri-food wastes and by-products could assure food security, maintain sustainability, efficiently reduce environmental pollution and provide an opportunity to earn additional income for industries. Furthermore, sustainable extraction methodologies like ultrasound-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, microwave-assisted extraction, pulse electric field-assisted extraction, ultrasound microwave-assisted extraction and high hydrostatic pressure extraction are extensively used for the isolation, purification and recovery of various bioactive compounds from agri-food waste, according to a circular economy and sustainable approach. This review also includes some of the critical and sustainable challenges in the valorisation of agri-food wastes and explores innovative eco-friendly methods for extracting bioactive compounds from agri-food wastes, particularly for food applications. The highlights of this review are providing information on the valorisation techniques used for the extraction and recovery of different bioactive compounds from agricultural food wastes, innovative and promising approaches. Additionally, the potential use of these products presents an affordable alternative towards a circular economy and, consequently, sustainability. In this context, the encapsulation process considers the integral and sustainable use of agricultural food waste for bioactive compounds that enhance the properties and quality of functional food.

Stem Rot of Pearl Millet Prevalence, Symptomatology, Disease Cycle, Disease Rating Scale and Pathogen Characterization in Pearl Millet-Klebsiella Pathosystem.

The oldest and most extensively cultivated form of millet, known as pearl millet (Pennisetum glaucum (L.) R. Br. Syn. Pennisetum americanum (L.) Leeke), is raised over 312.00 lakh hectares in Asian and African countries. India is regarded as the significant hotspot for pearl millet diversity. In the Indian state of Haryana, where pearl millet is grown, a new and catastrophic bacterial disease known as stem rot of pearl millet spurred by the bacterium Klebsiella aerogenes (formerly Enterobacter) was first observed during fall 2018. The disease appears in form of small to long streaks on leaves, lesions on stem, and slimy rot appearance of stem. The associated bacterium showed close resemblance to Klebsiella aerogenes that was confirmed by a molecular evaluation based on 16S rDNA and gyrA gene nucleotide sequences. The isolates were also identified to be Klebsiella aerogenes based on biochemical assays, where Klebsiella isolates differed in D-trehalose and succinate alkalisation tests. During fall 2021-2023, the disease has spread all the pearl millet-growing districts of the state, extending up to 70% disease incidence in the affected fields. The disease is causing considering grain as well as fodder losses. The proposed scale, consisting of six levels (0-5), is developed where scores 0, 1, 2, 3, 4, and 5 have been categorized as highly resistant, resistant, moderately resistant, moderately susceptible, susceptible, and highly susceptible disease reaction, respectively. The disease cycle, survival of pathogen, and possible losses have also been studied to understand other features of the disease.

Deciphering the biochemical and functional characterization of rice straw cultivars for industrial applications.

As an agricultural state, Haryana (India) produces about six million metric tons (mt) of rice straw every year from rice cultivation. Currently, rice straw is either burned or ploughed into the field without being turned into a functional product. Burning of paddy straw release green house gases and particulate matter (2.5 and 10 µm), which leads to air pollution and considerable loss of soil property viz. nutrients, organic matter, productivity and biodiversity, and on and off-farm humans and animals' health. The biochemically and functionally specified potential for optimal alternative use of the rice straw of 13 most widely produced rice varieties from Haryana's eastern and western agro-climate zones was undertaken. Pusa-1401 variety had the highest cellulose (46.55%) and silica content (13.70%), while Pusa-1718 had hemicellulose (28.25%) and lignin (11.60%), respectively. Maximum nitrogen (0.81%), phosphorus (0.32%) and potassium (2.78%) were found in rice variety Pusa-1509, Pusa-1401 and Rice-6129. The findings seemed to be statistically significant (p < 0.05). The biochemical profiles of rice straw cultivars were classified into distinct structural groups (C-H alkalanes, O-H alcohol, C[bond, double bond]O, C-H alkanes) based on the FTIR spectrum in order to find the best alternative possibilities for bioethanol and compost production. According to the study, these rice straw varieties could be used to make lucrative industrial products.

Biostimulation of Anaerobic Digestion Using Iron Oxide Nanoparticles (IONPs) for Increasing Biogas Production from Cattle Manure.

The effect of synthesised IONPs employing a nontoxic leaf extract of Azadirachta indica as a reducing, capping, and stabilizing agent for increasing biogas and methane output from cattle manure during anaerobic digestion (AD) was investigated in this study. Furthermore, the UV-visible spectra examination of the synthesized nanoparticles revealed a high peak at 432 nm. Using a transmission electron microscope, the average particle size of IONPs observed was 30-80 nm, with irregular, ultra-small, semi-spherical shapes that were slightly aggregated and well-distributed. IONPs had a polydisparity index (PDI) of 219 nm and a zeta potential of -27.0 mV. A set of six bio-digesters were fabricated and tested to see how varying concentrations of IONPs (9, 12, 15, 18, and 21 mg/L) influenced biogas, methane output, and effluent chemical composition from AD at mesophilic temperatures (35 ± 2 °C). With 18 mg/L IONPs, the maximum specific biogas and methane production were 136.74 L/g of volatile solids (VS) and 64.5%, respectively, compared to the control (p < 0.05), which provided only 107.09 L/g and 51.4%, respectively. Biogas and methane production increased by 27.6% and 25.4%, respectively using 18 mg/L IONPs as compared to control. In all treatments, the pH of the effluent was increased, while total volatile fatty acids, total solids, volatile solids, organic carbon content, and dehydrogenase activity decreased. Total solid degradation was highest (43.1%) in cattle manure + 18 mg/L IONPs (T5). According to the results, the IONPs enhanced the yield of biogas and methane when compared with controls.

Superabsorbent Polymers as a Soil Amendment for Increasing Agriculture Production with Reducing Water Losses under Water Stress Condition.

With an increasing population, world agriculture is facing many challenges, such as climate change, urbanization, the use of natural resources in a sustainable manner, runoff losses, and the accumulation of pesticides and fertilizers. The global water shortage is a crisis for agriculture, because drought is one of the natural disasters that affect the farmers as well as their country's social, economic, and environmental status. The application of soil amendments is a strategy to mitigate the adverse impact of drought stress. The development of agronomic strategies enabling the reduction in drought stress in cultivated crops is, therefore, a crucial priority. Superabsorbent polymers (SAPs) can be used as an amendment for soil health improvement, ultimately improving water holding capacity and plant available water. These are eco-friendly and non-toxic materials, which have incredible water absorption ability and water holding capacity in the soil because of their unique biochemical and structural properties. Polymers can retain water more than their weight in water and achieve approximately 95% water release. SAP improve the soil like porosity (0.26-6.91%), water holding capacity (5.68-17.90%), and reduce nitrogen leaching losses from soil by up to 45%. This review focuses on the economic assessment of the adoption of superabsorbent polymers and brings out the discrepancies associated with the influence of SAPs application in the context of different textured soil, presence of drought, and their adoption by farmers.

Organic Farming and Bio-Nanomaterial Conflux: A Way Forward for Sustainable Agriculture.

Increasing population pressure and decreasing cultivable land brought the agricultural sector at an alarming situation of food production particularly in the developing countries. To feed the burgeoning population, the agriculture sector needs to become more productive and diversified while facing the adversity of climate change and limitations of natural resources. During 1960-70, the improved irrigation facilities, the use of fertilizers and pesticides in the cultivation of high yielding varieties of cereals successfully led to the Green revolution in India. In the present scenario, the low irrigation and fertilizer use efficiencies, poor pesticide application and delivery are amongst the important issues in developing countries that need to be addressed for getting higher productivity. Also, fertilizer and pesticide usage also had severe associated environmental consequences like eutrophication, resistance and resurgence in pest, toxicity to non-target organisms, residues in food and feed, accumulation in the environment, etc. In such conditions, organic farming, a traditional practice coupled with the exploration of bio-nanoparticles to achieve a sustainable production system seems to be a better option. This review focuses on current research developments in the areas of bio-nano-enabled crop nutrition, protection, post-harvest management, and the possibility of bio-nanomaterials and organic farming confluence to revolutionize the agricultural sector by ensuring sustainable food security for coming generations.

Dissipation and decontamination behavior of pre-mix formulation of tebuconazole and rifloxystrobin fungicides in okra.

The present study was done to assess the dissipation behavior, decontamination, and half-life time of ready-mix formulation of trifloxystrobin (25% w/w) and tebuconazole (50% w/w) in okra and soil under the crop after foliar spray at fruiting stage. Samples of okra and soil were collected periodically, i.e., zero (2 h after spray), 1, 3, 5, 7, 10, 15, 20, and 25 days after third application at a 7-day interval. Residues of these fungicides were determined by gas liquid chromatography (GLC) equipped with electron capture detector (ECD) and gas chromatography-tandem mass spectrometry (GCMS-triple quadruple). The limits of quantification (LOQ) and detection (LOD) for both the fungicides were 0.01 and 0.003 mg kg-1, respectively. Washing alone with faucet water was found successful in minimizing the residues. Soil was free from residual contamination at fifth day after spraying in case of both the fungicides and at both the doses.

Persistence and decontamination studies of chlorantraniliprole in Capsicum annum using GC-MS/MS.

Chlorantraniliprole, a new systemic insecticide of anthranilic diamide class gaining popularity among farmers for its effective control of Lepidoptera pest particularly in vegetables. Thus monitoring of chlorantraniliprole (CAP) leftover in vegetables is required and to this end eco-friendly, cost effective, selective and accurate method was developed and validated for quantification of its left over in chilli fruit using gas chromatography-tandem mass spectrometry (GC-MS/MS) in SCAN/MRM mode with a triple Quadrupole analyzer. Two MS-MS transitions were acquired to ensure the reliable quantification and confirmation of the analyte. All calibration curve showed a good linear relationship (r > 0.99) with in test ranges (0.005-0.5 µg ml-1). To study its persistence, half-life, waiting period and decontamination behavior the field trial were performed at recommended dose and its double by Central Insecticide Board and Registration Committee (CIBRC). Initial deposits of CAP at recommended (T1) and double (T2) the recommended doses revealed 3.16 and 4.18 mg kg-1 with their respective half-lives 1.18 and 2.05 days respectively. According to maximum residual limit i.e. 0.03 mg kg-1 by FSSAI, residues persists up to 7th and 15th day if sprayed at fruit setting stage. The extent of removal of CAP using simple decontamination approach showed 62-67% reduction on maximum residue.

Characterization and optimization of conditions for biodegradation of sella-rice mill effluent.

The sella-rice mill effluent is a major environmental pollutant requiring proper treatment before disposal. The present study has been conducted to isolate and characterize micro-organisms capable of growing on sella-rice effluent and to optimize conditions for its rapid bioremediation. Using three different types of media (LB, YEPDA and PDA), a total of 139 isolates were isolated from effluent samples collected from three different locations. Out of these, 45 isolates were found to utilize starch on starch medium, eight isolates showing high efficiency. For the optimization of conditions for maximum utilization of starch by selected isolates, parameters such as effect of addition of carbon and nitrogen sources, effect of growth factors, temperature and pH were studied. Maximum growth (absorbance of 2.10) and starch-utilization (varying in the range of 2.33 to 3.62) was observed on starch medium supplemented with peptone and yeast extract at 30 degrees C with a pH of 6.0. These bacterial isolates also reduced the amount of starch (80.10%), BOD (64.24%) and COD (75.0%) of sella-rice mill effluent after 15 days of incubation. On the basis of morphological and biochemical characteristics, the selected isolates were found to belong to the genera Lactobacillus and Micrococcus.