The timing of exogenous ethylene supplementation differentially affects stored sweetpotato roots

The effects of continuous supplemental ethylene (10 μL L−1) timing on the physiology and biochemistry of sweetpotato roots during storage at 25 °C were examined. Alongside continuous ethylene or air treatments, a subset of the roots were transferred at dormancy break, from those previously stored in ethylene into air and vice-versa. The study showed distinctive ethylene-induced effects on the metabolism of individual sugars, phenolic compounds and phytohormones (abscisic acid and zeatin riboside) across the spatial gradient of the root flesh and skin tissues. Although ethylene flushing doubled root respiration, sprout growth was significantly suppressed. Supplementation of roots with ethylene after dormancy break effectively inhibited sprout growth as much as continuous ethylene alone. On the other hand, truncating ethylene application after dormancy release promoted vigorous sprout growth. After prolonged storage, ethylene treatment was associated with increased weight loss and incidence of proximal rots. Supplemental ethylene also accelerated the catabolism of monosaccharides, and promoted accumulation of phenolic compounds in the proximal root sections

Performance evaluation of a chimney solar dryer for Habanero pepper (Capsicum chinense Jacq)

Habanero pepper (Capsicum chinense Jacq) is cultivated predominantly in the Volta, Central and Ashanti regions of Ghana and commonly utilised in  most local dishes. Majority of consumers prefer the dried form of the pepper. However, farmers are usually confronted with the challenge of  obtaining low-cost, locally fabricated dryers that can efficiently dry agricultural produce while mitigating quality and safety concerns. In this study, a model of the newly designed chimney solar dryer by the Horticulture Innovation laboratory of the University of California, Davis, in the United States of America, for crop drying in developing countries was constructed and its performance evaluated in comparison to open sun drying. Habanero pepper was used as a test crop. Subsequently, microbial analysis was carried out on the dried products. The mean chimney dryer temperature (46.4°C) was found to be higher than the ambient temperature (36.2°C). The relative humidity in the chimney solar dryer and the ambient ranged from 25% to 68% and 26% to 83%, respectively. During the period of the drying experiment, mean maximum solar insolation of 823.18 W/m2 was  recorded at 11.30 am while a mean minimum solar insolation of 107.84 W/m2 was recorded at 4.30 pm. The solar-dried and sun-dried pepper  recorded total drying time of 35 h and 55 h respectively. The mean performance coefficient of the chimney solar dryer was determined to be 1.21 which gives an indication of a high dryer performance. The mean yeasts and moulds counts of the solar-dried and sun-dried pepper were 4.30 x 104 cfu/g and 2.52 x 105 cfu/g, respectively. Also, the Staphylococcus aureus and Escherichia coli counts were <10 cfu/g for samples in both drying media. In conclusion, the chimney solar dryer was found to have performed better than open sun drying with shorter drying time and better qualityof the dried product. Key words: chimney, habanero pepper, open sun drying, performance, quality, solar drye

Temperature, microwave power and pomace thickness impact on the drying kinetics and quality of carrot pomace

This study investigated the effect of air temperature, microwave power, and pomace thickness on the drying kinetics and quality of dried carrot pomace. The study established that the drying of carrot pomace occurs in the falling rate period, suggesting that drying was driven by molecular diffusion. The microwave-drying moisture diffusivity increased with microwave power and ranged between 1.57×10–8 and 2.61×10–8 m2/s. As regards convective air-drying, the moisture diffusivity values were between 3.38×10–10 and 8.27×10–10 m2/s. The microwave powerto-mass activation energy was 15.079 W/g for 5 mm, 7.599 W/g for 10 mm and 9.542 W/g for 15 mm dried samples. Meanwhile, the temperature-dependent activation energy for carrot pomace was found to be 27.637 kJ/mol for 5 mm, 17.92 kJ/mol for 10 mm and 38.76 kJ/mol for 15 mm thickness pomace. Generally, drying time decreased with increasing microwave power or air temperature. The ascorbic acid content of the fresh carrot pomace reduced after both microwave and convective air-drying. However, microwave power, and sample thickness had significant effect on the β-carotene content of dried products but air temperature did not have a significant effect. The effect of temperature and sample thickness on brown pigment formation was substantial with air temperature compared to microwave. The study has demonstrated that microwave drying, compared to conventional drying, enhances moisture removal, drying time, and preservation of carotenoids and ascorbic acid. Therefore, microwave drying can be considered as an alternative method for obtaining quality dried carrot pomace

The effects of ethylene on sweetpotato storage

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important food security crop in many parts of the developing world. Despite its economic value and growing contribution to nutrition and health in tropical and sub-tropical countries, sweetpotato has a short postharvest life. Inhibition of sprout growth to permit long-term storage and marketing of the roots is a major challenge in the sweetpotato industry. To date, no technically and economically satisfactory method is available to extend the tropical storage of sweetpotato. Previous studies have demonstrated the efficacy of both exogenous ethylene and the ethylene perception inhibitor 1-methylcyclopropene (1-MCP) in suppressing sprout growth in other root crops such as potato and onion, which display differential endodormancy. It has been proposed, through studies by others, that ethylene and 1-MCP may also enhance sweetpotato storage. In the present study, the physiological and biochemical effects of exogenously applied ethylene and 1-MCP were further investigated. Cont/d

Adaptation of the Wound Healing Questionnaire universal-reporter outcome measure for use in global surgery trials (TALON-1 study): mixed-methods study and Rasch analysis

BackgroundThe Bluebelle Wound Healing Questionnaire (WHQ) is a universal-reporter outcome measure developed in the UK for remote detection of surgical-site infection after abdominal surgery. This study aimed to explore cross-cultural equivalence, acceptability, and content validity of the WHQ for use across low- and middle-income countries, and to make recommendations for its adaptation.MethodsThis was a mixed-methods study within a trial (SWAT) embedded in an international randomized trial, conducted according to best practice guidelines, and co-produced with community and patient partners (TALON-1). Structured interviews and focus groups were used to gather data regarding cross-cultural, cross-contextual equivalence of the individual items and scale, and conduct a translatability assessment. Translation was completed into five languages in accordance with Mapi recommendations. Next, data from a prospective cohort (SWAT) were interpreted using Rasch analysis to explore scaling and measurement properties of the WHQ. Finally, qualitative and quantitative data were triangulated using a modified, exploratory, instrumental design model.ResultsIn the qualitative phase, 10 structured interviews and six focus groups took place with a total of 47 investigators across six countries. Themes related to comprehension, response mapping, retrieval, and judgement were identified with rich cross-cultural insights. In the quantitative phase, an exploratory Rasch model was fitted to data from 537 patients (369 excluding extremes). Owing to the number of extreme (floor) values, the overall level of power was low. The single WHQ scale satisfied tests of unidimensionality, indicating validity of the ordinal total WHQ score. There was significant overall model misfit of five items (5, 9, 14, 15, 16) and local dependency in 11 item pairs. The person separation index was estimated as 0.48 suggesting weak discrimination between classes, whereas Cronbach's α was high at 0.86. Triangulation of qualitative data with the Rasch analysis supported recommendations for cross-cultural adaptation of the WHQ items 1 (redness), 3 (clear fluid), 7 (deep wound opening), 10 (pain), 11 (fever), 15 (antibiotics), 16 (debridement), 18 (drainage), and 19 (reoperation). Changes to three item response categories (1, not at all; 2, a little; 3, a lot) were adopted for symptom items 1 to 10, and two categories (0, no; 1, yes) for item 11 (fever).ConclusionThis study made recommendations for cross-cultural adaptation of the WHQ for use in global surgical research and practice, using co-produced mixed-methods data from three continents. Translations are now available for implementation into remote wound assessment pathways