Suitability of charcoal-cement passive evaporative cooler for banana ripening

Abstract

The common banana ripening methods practiced by fruit sellers are application of calcium carbide or 'ethrel'. Ethrel is expensive and therefore the ethylene analogue calcium carbide is commonly used although it contains heavy metals as it is readily available. Therefore a passive evaporative cooler made of charcoal, cement and sand was tested as a ripening chamber for banana as the internal relative humidity and temperature were ideal for banana ripening. The evaporative cooler maintained a high relative humidity of around 90-98% with a 3 o C temperature reduction than room temperature during the test period. In the experiment, banana cultivars were allowed to ripen with 1000ppm ethrel and without ethrel, in two evaporative coolers and in two corrugated fibreboard boxes with the same dimensions of the cooler, under room conditions. Fruits from a single hand were subjected to all treatments and four parameters; TSS, peel colour, firmness and weight were tested. There were no significant differences of TSS, peel colour and firmness among four treatments. However for all cultivars, the weight loss was 16-22% for fruits ripened in the boxes while the weight loss was 3-6% .for those ripened in the evaporative cooler.

Effect of 1-methylcyclopropene, potassium permanganate and packaging on quality of banana

“…The longest delay in colour change was observed in fruits treated with 1-MCP and placed in perforated polyethylene in which the fruits were just at full yellow colour stage on the last date of storage (28 days). The peel colour development from green to yellow (stages 1 to 6) in this study is in agreement with the 1 to 2 weeks duration reported before (Siriboon and Banlusilp, 2004;Dharmasenal and Kumari, 2005;Salvador et al, 2006). The conversion of green colour of the peel into yellow as a result of chlorophyll degradation is an indicator of senescence that is enhanced by high rate of respiration which in turn is regulated by temperature, ethylene, O 2 and CO 2 gases (Pinto et al, 2004).…”

“…The low storage room relative humidity (35 to 58%), in addition to possible respiratory loss, could have aggravated the weight loss at ambient while in other treatments either of these causes might have been affected. This result corresponds with the weight loss value reported by Dharmasenal and Kumari (2005) for fruits stored under open ambient condition for the same period. The lower weight loss obtained from fruits placed in polyethylene bags with perforation compared to those in non-perforated ones could be due to removal of ethylene which has a catalytic role in increasing respiration (Jobling, 2000) while also maintaining RH in the package thus reducing water loss.…”

“…In all treatments, the percentage weight loss increased with storage time as ripening progressed, which possibly resulted from transpiration and respiration of the fruits. Excess energy produced from the respiration process in the form of heat is released from the fruit by evaporation of water causing a weight loss (Siriboon and Banlusilp, 2004;Dharmasenal and Kumari, 2005). Similarly, increase in the membrane permeability following the respiratory climacteric could result in loss of moisture through the peel (Siriboon and Banlusilp, 2004) as evidenced in this study by the shrinkage on the peel.…”

“…Strong and positive correlation was also observed between firmness of fruits and ascorbic acid content and marketability of the fruits while it showed negative correlation with colour, and weight loss (Table 6) indicate that the treatments delayed loss of firmness and improved marketability and quality of the fruits. As indicated earlier, the steady reduction in fruit firmness during the storage period is a natural process of ripening of almost all fleshy fruits as a result of biochemical changes of the cellular structure (Brady, 1987;Seymour, 1993;Dharmasenal and Kumari, 2005). According to Seymour (1993), softening of fruits is related to a change in cell wall components and starch degradation.…”

Effect of Post Harvest Treatments on Quality and Shelf Life of Banana Cv. Grand Naine.

“…In all treatments the percentage weight loss increased with the storage time and ripening progressed, which possibly resulted from transpiration and respiration of the fruits. Energy produced from the respiration process in the form of heat is released from the fruit by evaporation of water causing a weight loss (Dharmasena and Kumari 2005). Loss in weight by various treatments also has also been reported by Mahajan et al (2010) in banana cv.…”