Roseworthy College

Cotton stalk (CS) is a global agricultural residue, with an annual production of approximately 50 million tons, albeit with limited economic significance. The utilization of cellulose derived from CS has gained significant attention in green nanomaterial technologies. This interest stems from its unique properties, including biocompatibility, low density, minimal thermal expansion, eco-friendliness, renewability, and its potential as an alternative source for chemicals, petroleum, and biofuels. In this review, we delve into various extraction and characterization methods, the physicochemical attributes, recent advancements, and the applications of cellulose extracted from CS. Notably, the steam explosion method has proven to yield the highest cellulose content (82 %) from CS. Moreover, diverse physicochemical properties of cellulose can be obtained through different extraction techniques. Sulfuric acid hydrolysis, for instance, yields nanocrystalline cellulose fibers measuring 10-100 nm in width and 100-850 nm in length. Conversely, the steam explosion method yields cellulose fibers with dimensions of 10.7 μm in width and 1.2 mm in length. CS-derived products, including biochar, aerogel, dye adsorbents, and reinforcement fillers, find applications in various industries, such as environmental remediation and biodegradable packaging. This is primarily due to their ready availability, cost-effectiveness, and sustainable nature.

Consistently monitoring groundwater quality (GWQ) is essential to reduce the risk of geochemical contaminants and ensure its suitability for agriculture and human consumption. The current investigation aims to assess GW acceptability in the Nand Samand catchment (NSC), utilizing the water quality index (WQI) and irrigation water quality indices (IWQIs) for domestic and irrigation purposes. To achieve this, GW samples were collected from 95 open wells which were located spatially in the catchment, during the pre-monsoon (PRM) and post-monsoon (POM) seasons of 2019 and 2020, and subsequently analysed for 11 physico-chemical parameters. Electrical conductivity (EC) varied from 1.25 to 6.61 dS/m and 0.58 to 7.42 dS/m during the PRM and POM seasons, respectively. Total dissolved solids of the study area ranged between 180 and 1,180 (27%) to 1,180 and 2,180 (62%) during PRM 1,180 (63%) to 1,180-2,180 (31%) during POM, respectively. The study also computed the 'sodium adsorption ratio' (SAR) and 'residual sodium carbonate' (RSC) to estimate GW's appropriateness for agriculture, finding it suitable in most locations due to its balanced composition. Based on WQI, varying percentages of samples were classified as 'good' and 'poor' for potable water quality in both seasons.

Pulsed light (PL), a relatively new non-thermal technology can be used as a possible substitute to the conventional (thermal and chemical) technology for disinfecting a wide variety of fruits and vegetables. The short-duration light pulses, ranging from 1 to 20 flashes per second with an energy density of about 0.01–50 Jcm−2, ensure the killing of several disease-causing microorganisms by causing minimal impact on the quality parameters in fruits and vegetables. This technology enhances safety and extends shelf-life period of fruits and vegetables. Furthermore, PL decreases or inhibits the harmful effect of conventional techniques on nutritional components. The review discusses recent research on PL's influence on nutritional and physicochemical parameters and its potential applications for extending the shelf life of fruits and vegetables. This PL technology can be successfully employed alone or in combination with other techniques for enhancing fresh produce life. PL is considered a safe, eco-friendly and non-thermal technique for shelf-life extension. For this review article, keywords such as pulsed light, fruits and vegetables, microbial safety and shelf life were selected and most relevant papers were cited. Thus, the present review article, supported by 70 references, highlights the novel potential of PL treatment and its diverse applications in the fruit and vegetable sector.

Black soybean (BS) is a nutritious legume that is high in proteins, essential amino acids, dietary fiber, vitamins, minerals, anthocyanins, phenolic acids, isoflavones, and flavones. Traditional approaches for extracting BS bioactive compounds are commonly employed because they are simple and inexpensive, but they use toxic solvents and have lower yields. As a result, new extraction techniques have been developed, such as microwave, ultrasound, and enzyme-assisted extraction. Modern approaches are less harmful to the environment, are faster, and produce higher yields. The major anthocyanin in the BS seed coat was discovered as cyanidin-3-O-glucoside, accounting for nearly 75% of the total anthocyanins. BS and its seed coat also contains phenolic acids (p-hydroxybenzoic, gallic, vanillin, syringic acid), isoflavones (daidzein, glycitein and genistein), flavones, flavonols, flavanones, and flavanols. Bioactive compounds present in BS exhibit antioxidant, anti-cancerous, anti-diabetic, anti-obesity, anti-inflammatory, cardio and neuroprotective activities. The characterization and biological activity investigation of these bioactive compounds has provided researchers and food manufacturers with valuable information for developing functional food products and nutraceutical ingredients. In this review, the nutritional makeup of BS is reviewed, and the paper seeks to provide an insight of bioactive compound extraction methods as well as bioactive compounds identified by various researchers. The biological activities of BS extracts and their potential applications in food products (noodles), biodegradable films (pH sensitive film), and therapeutic applications (wound healing and anti-inflammation) are also discussed in the study. Therefore, BS have enormous potential for use in developing functional foods and nutraceutical components. This is the first review of its sort to describe and explain various extraction methodologies and characterization of bioactives, as well as their biological activity recorded in diverse works of literature, making it possible for food manufacturers and scientists to get a quick overview.

Green technologies and smart solvents are garnering attention with growing environmental concerns. These techniques and solvents can assist in reducing the hazardous impact of toxic chemicals used in conventional extraction techniques. Further, there are ample studies reporting their use for extraction of bioactive compounds from plant and plant-based material, however, limited studies are conducted on their combined or integrated use. The current literature available proves that green technologies can reduce the extraction time, increase the yield and are environment friendly. Further, to enhance this extraction efficiency combination green technologies can be applied. This review highlights with ample number of case studies the beneficial impact of combination green techniques and solvent in extraction of bioactive compounds. Up scaling of these combinations from laboratory to industrial scale can be beneficial from cost and purity point of view. Commercializing and popularising the use of these environment friendly combination techniques also reduces the load on environmental pollution and is a step towards sustainability.