The effect of traditional and improved solar drying methods on the sensory quality and nutritional composition of fruits: A case of mangoes and pineapples

Abstract

Background: This study investigated the effect of traditional and improved solar drying methods on the sensory quality and nutritional composition of the dried fruit products; using mangoes and pineapples, as a case study. The fruits were dried under five solar drying methods namely; open sun drying (OSD), black-cloth shade (BCS), whitecloth shade (WCS), a conventional solar dryer (CSD), and a newly improved solar dryer (ISD) technology. The ISD unit was made of a modified solar concentrator plate containing multiple metallic solar collectors arranged in series. The ISD drying cabinet was also enclosed with a specialized greenhouse cover materials. The drying operations were conducted following a completely randomized design (CRD) experimental procedure. Results: The mean drying air temperatures for the OSD, BCS, WCS, CSD and ISD methods were 26.8, 26.7, 24.5, 32.6 and 40.3 C; respectively. Results showed that the five solar drying methods were capable of retaining the sensory quality and nutritional composition of dried mango and pineapples. The nutritional parameters retained were proximate and mineral content. The sensory quality parameters were taste, aroma, colour and acceptability of the dried fruit products. However, the sensory quality and nutritional content of the fruit products dried under the ISD method were higher than that of the products dried under the CSD method, suggesting an enhanced capacity and superior role of the ISD dryer technology in fruit processing. Conclusion:The ISD technology was, therefore, recommended as a better fruit drying method than the traditional solar drying methods. Using the ISD method could be a feasible solution and a strategic pathway to addressing the high post-harvest losses of fruits as well as other perishable fresh produce in East Africa.

Effect of different drying methods and storage conditions on physical, nutritional, bioactive compounds and antioxidant properties of doum (Hyphaene thebaica) fruits

“…(2018) , who found significant increase of titrable acidity of frozen apricots during storage of 90 days. Mohammed et al. (2020) have also reported an increase of acidity in mango and pineapples dried in various methods.…”

“…These decreases may be due to non-enzymatic browning reactions occurring during thermal processing of fruit samples. Mohammed et al. (2020) found also a variation of total carbohydrates and sugars content when mango and pineapples were subjected to different drying methods.…”

“…(2018) . Also, Mohammed et al. (2020) reported a reduction of total phenolics content from mango and pineapples dried by different methods.…”

Effect of Selected Drying Methods and Emerging Drying Intensification Technologies on the Quality of Dried Fruit: A Review

“…Applied higher temperatures and prolonged exposure to oxygen could ultimately decrease vitamin content during the drying of fruits [78]. Nevertheless, one study concluded that applied solar drying even at lower temperatures (24.5-40.3 • C) could significantly (p < 0.05) reduce the vitamin content in the fruits [79]. Due to dehydration of the pieces to a moisture level of 10% or even lower, the relative increases in the concentrations of the mineral content, total acidity, carbohydrates and total sugars were significantly higher in the dried fruits as compared to the fresh samples.…”

Application of immersion pre-treatments and drying temperatures to improve the comprehensive quality of pineapple (Ananas comosus) slices

“…Pineapple is one of the most desired and generally consumed succulent non-citrus fruits, mainly for its splendid sensorial characteristics and revitalizing sugar action. It has been considered as a vibrant source of the essential nutritients, such as minerals, vitamins (vitamin C, thiamine, vitamin B 6 , folate), antioxidants, dietary fiber, etc ( Mohammed et al., 2020 ; Bartolomé et al., 1995 ; Ramallo and Mascheroni, 2012 ). The demand of pineapple for internal consumption and also for export is increasing day by day.…”