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Abstract Fresh onions are dehydrated to increase their shelf-life. Primarily, open dehydration techniques like solar dehydration come with the problem of contamination through natural air convection. A solar conduction dryer that uses conduction, convection, and radiation for dehydration of food samples is exploited in this study. The food samples are often contaminated by Bacillus and Aspergillus species spores. As a remedy, pulsed light treatment as a non-thermal technology and infrared treatment as a thermal technology are studied and compared. Bacillus cereus and Aspergillus niger spores are chosen as a representative of bacterial and fungal contamination in onions. Dehydrated onion shreds with varying water activities (0.4, 0.5, 0.6) were treated. The spore inactivation was best described by Weibull model as compared with first-order model. Scanning electron microscopy images of the microbial cells showed surface distortions on the bacterial and fungal spores. The effect of the treatment technologies on the colour, flavour (thiosulphinate and pyruvic acid concentration), total phenolic and flavonoid content, and ascorbic acid concentration are compared. Overall, pulsed light treatment showed promising inactivation with a maximum log reduction of 4.5 log B. cereus spores·g−1 and 3.1 log A. niger spores·g−1 at 2.131 J·cm−2 in samples with water activity 0.6. The inactivation rate increased with an increase in water activity. The colour was better retained in pulsed light treated samples. The thiosulphinate content (9.24 μmol·g−1), total phenolics (0.268 mg GAE·g−1), and flavonoid content (0.344 mg QE·g−1) in the sample were improved upon pulsed light exposure. Graphical Abstract

Processing of dehydrated onion shreds involves contamination during peeling, chopping, and dehydration. Pre-treatments such as blanching, dipping and soaking in chemical solutions reduce the contamination prior to dehydration. Post dehydration treatments include thermal and non-thermal technologies. Hot water blanching in presence of CaCl2 as pre-treatment followed by pulsed light of 2208 ± 0.5 J·cm−2 (2100 V, 120 s) as post-dehydration treatment is employed. Further, the microbial quality and other attributes were assessed during the storage at 25, 30, and 37 °C. The population for aerobic mesophiles and yeasts & molds crossed 5 and 4 log CFU∙g−1, respectively after 30, 27, 19 days of storage at 25, 30, and 37 °C, respectively. Browning index, pyruvic acid, total phenols and flavonoids were most sensitive among the color parameters and bioactive compounds degraded during storage. After 30 days of storage at 25 °C, there was reduction of 82% in ascorbic acid, 39% in pyruvic acid, 93% in thiosulphinate, 50% in total phenolics, and 52% in total flavonoids content of the shreds. At 37 °C, the rate of bioactive degradation was higher and the retention in bioactives after 19 days was 24, 56, 35, 35, and 52% of ascorbic acid, pyruvic acid, thiosulphinate, total phenolics, and total flavonoids content, respectively. The pyruvic acid, ascorbic acid, phenolic and flavonoid content in the onion shreds degraded following first order kinetics, whereas thiosulphinates followed zero order degradation. The shelf-life of the pulsed light decontaminated dehydrated onion shreds was 30, 27, 19 days at 25, 30, and 37 °C, respectively. Pulsed light treatment is recommended for dehydrated onion shreds as an effective technology for microbial inactivation.

Background: Vaginal dryness is common during and after menopause due to declining oestrogen, vulvovaginal atrophy (VVA), up to about a year after delivery during breast feeding and in many other conditions. This can be distressing to painful for women and may cause discomfort and dyspareunia. This study was performed to evaluate the use and practicability of secretions of male bulbourethral glands (Cowper's glands) to alleviate the discomfort, dyspareunia or pain at sexual activity, because of inadequate lubrication of vagina. Method: When a healthy male is sexually aroused, Cowper's glands produce a mucous-like fluid called pre-ejaculate. This fluid is a clear, colourless, viscous, and salty liquid, which is emitted from the urethra of the penis. A lubrication free wet condom on penis during foreplay can prevent loss of these secretions during an extended foreplay and lubrication around penis due to these secretions can effectively serve as physiological lubricant during coitus. Result: This technique and secretion of Cowper’s glands are a good lubrication for dryness of vagina during coitus. Sexual function assessment revealed a marked improvement in all domains of sexual function to both partners. A physiological secretion being natural to the sexual act and providing motive for extending foreplay; it is arguably the best lubricant for coitus in situations of dry vagina. Conclusion: Supposedly the secretions may also help in reducing dose of HRT for menopause, extended foreplay adds to psychosexual benefits and a boost to sexual hormonal milieu.

Essential oils are natural volatiles extracted using steam. Steam generation is an energy-intensive process and is invariably based on fossil fuels, briquettes or biomass. Based on the volumes of essential oil extracted, it can be considered as significant contributor to greenhouse gases. Though a lot of work is reported on essential oil extraction and characterisation, method for quantification of exact steam requirement and means for achieving it through sustainable source is not much reported.Through this study, steam requirement of 750 g/ml of Betel leaf volatile oil extracted and quantification of energy requirements for the extraction process is determined. For adoption of sustainable and clean energy source, opto-geometric optimisation and concentrating solar collectors (CSC) area calculation are carried out. The design of three CSC, namely, Linear Fresnel Reflector (LFR), parabolic dish collector (PDC) and parabolic trough collector (PTC), resulted in 78 m2, 122 m2 and 138.87 m2 of area to meet the steam requirement of the process.Adoption of CSC technologies for steam generation and replacing the prevalent technology needs detailed analysis and techno-economic comparison. This paper also focuses on cost-benefit analysis, taking into account CAPEX, OPEX, life-span, return on investment, levelized energy (steam) cost and the profitability index of net present value, payback period and internal rate of returns to check the economic feasibility of renewable energy. Analysis indicates that the cost associated with unit steam generation through CSC over the specified period is lower than a briquette-based steam generation. On adopting this sustainable technology for betel leaf oil extraction, even if the initial cost seems to be high, the payback period of LFR and PTC are 1.10 and 2.45 years, respectively. Based on this study, CSCs can provide a sustainable green solution for the extraction of essential oils.

Onion and dehydrated onion products are produced and consumed more than any other agriproduct in India. Massive losses are seen due to poor storage conditions, and thereby, economic loss. Dehydration of onion products is commonly employed to extend the shelf-life and facilitate bulk handling. However, spoilage and pathogenic microorganisms have been reported to contaminate onion and its dehydrated products throughout the process line. To comply with the stringent regulatory aspects, optimizing the decontamination process specific to onion products is necessary. This review corroborates the decontamination technologies applied for onion and dehydrated onion products, including thermal, non-thermal, chemical, and biological methods. Further, a comparison of the efficacy of these treatments on fresh and dehydrated onion products along with a general operating cost estimation has been discussed. This will help the industry select the suitable decontamination technique for dehydrated onion products and design the process thereof. The value added by the decontamination process to the industry and the regulatory bodies have been discussed.

Microbial contamination of dehydrated onion products is a challenge to the industry. The study focused on opting for a suitable drying condition for minced onion and exploring the decontamination efficacy of pulsed light (PL) treatment conditions for the dehydrated product. The minced onions were hot air dried at 55–75°C for 280 min. The drying condition selected was 195 min at 75°C with a final water activity of 0.5 and moisture content of 7% (wet basis [w.b.]). The weight losses, browning indexes (BI), shrinkage volumes (%), and thiosulfinate content were considered. The dehydrated product was exposed to PL treatment corresponding to an effective fluence range of 0.007–0.731 J/cm2. A fluence of 0.444 J/cm2 (1.8 kV for 150 s) achieved 5.00, 3.14, 2.96, and 2.98 log reduction in total plate count, yeast and mold count, Bacillus cereus 10876, and Escherichia coli ATCC 43888, respectively. The PL‐treated sample (0.444 J/cm2) produced a microbially safe product with no significant difference in the moisture contents (%w.b.) and water activity (aw) from the untreated dehydrated sample. Further, a 30.9% increase in the BI and a 4.25% depletion in thiosulfinate content were observed after PL treatment. An optimum drying combination (75°C for 195 min) of minced onion followed by decontamination using pulsed light treatment at 0.444 J/cm2 fluence satisfies the microbial safety and quality. Practical Application: Dehydrated minced onion can be used for dishes requiring low water content and short cooking time. It is helpful during shortages, high price fluctuations, and famines. [ABSTRACT FROM AUTHOR]

Open sun drying is the predominant process used for food preservation by smallholder and subsistence farmers (SHSFs), and their families, globally constituting about 2 billion people on about 475 million farms. The major problems with this process are the slow, unreliable speed of completion, rain-caused loss of vital food sources, risks from mycotoxin accumulation, environmental contamination, and loss of nutritional quality. SHSFs represent the poorest and least educated human demographic, whose survival is largely ignored by Governments, untouched by international aid programs, and with limited access to basic utilities. Solar drying systems can greatly improve the preservation of safe and nutritious food, but current systems deployed put this technology beyond the reach of the demographic which needs it most. Here, our objective was to develop the technology for the simplest low-cost drying system, which would minimize all risk factors, particularly eliminate mycotoxin accumulation, and which could be practically deployed by SHSFs. [ABSTRACT FROM AUTHOR]