MSc

The present study entitled “Development of osmo dehydrated Red Banana (Musa spp.)” was carried out at the Department of Post Harvest Technology, College of Agriculture, Vellayani during the period 2017-2019 with the objectives to standardize different process variables viz., fruit slice shape, osmotic concentration and immersion time for osmo dehydration of red banana and to assess the storage stability of osmo dehydrated product.
Good quality uniform sized, fully ripe red banana were sliced into three shapes viz., ring, round and chunks of thickness 5 mm and osmosed in sugar syrup of 40oBrix, 60oBrix and 80oBrix concentration with an immersion time of 60, 120 and 180 minutes. After the osmotic treatments, the samples were analysed for different mass transfer characters. The osmosed red banana slices were finally dehydrated in a cabinet drier at 50oC till the product attained a moisture content of 17(+1)% and analysed for biochemical, physical and sensory quality parameters.
Mass transfer characters viz., solid gain, water loss and percentage weight reduction increased with increase in osmotic concentration and immersion time irrespective of fruit shapes. Maximum solid gain (8.90%), water loss (9.59%) and weight reduction (10.00%) with a water loss to solid gain ratio of 1.07 was observed in osmo dehydrated red banana chunks at an osmotic concentration of 80oBrix with 180 minutes immersion time. Biochemical characters viz., TSS, total sugar and reducing sugar increased with increase in osmotic concentration and immersion time whereas acidity, vitamin C, antioxidant activity and carotenoid content decreased. Osmo dehydrated red banana rings recorded a TSS of 59.49oBrix, total sugar of 52.27%, reducing sugar of 36.63%, 8.33 mg 100g-1 vitamin C, 0.68% acidity, 94.54% antioxidant activity and 6.00 µg 100g-1 carotenoids and it varied with shapes. Physical characters viz., yield, rehydration ratio, textural quality and colour were analysed. The highest yield (31.75%) was observed for osmo dehydrated red banana chunks at 80oBrix and 180 minutes immersion time and it was 30.37% and 29.58% for ring and round slices respectively. The lowest hardness (1.24 kg) and cutting energy (0.72 kg s) was noticed in osmo dehydrated red banana chunks at 80oBrix and 180 minutes immersion time.
Sensory evaluation of osmo dehydrated ring, round and chunk shaped slices were conducted and kruskal wallis test confirmed significant difference among the treatments for sensory attributes. Osmo dehydrated red banana rings, rounds and chunks recorded the highest acceptance for all the sensory attributes at 80oBrix for an immersion time of 180 min. Based on the mass transfer, biochemical, physical and sensory analysis, three best treatments; one from each shape were selected (ring, 80oBrix, 180 min; round, 80oBrix, 180 min and chunks, 80oBrix, 180 min). The best treatments selected were subjected to 2% and 4% corn starch treatment and sensory analysis revealed that corn starch treated samples were not acceptable when compared with untreated samples.
The three selected osmo dehydrated red banana were packed in 200 gauge polypropylene and stored at room temperature were analysed for biochemical, microbial and sensory qualities at monthly interval for four months. During storage, 3.26% increase in TSS (53.73oBrix to 55.48oBrix), 4.62% increase in total sugar (53.72% to 56.20%) and 6.70% increase in reducing sugar (37.30% to 39.80%) were observed whereas a decrease of 51.61% in acidity (0.62% to 0.30%), 10.11% in vitamin C (9.59 mg 100g-1 to 8.62 mg 100g-1), 2.86% in antioxidant activity (93.85% to 91.17%) and 28.59% reduction in carotenoid content (7.52 µg 100g-1 to 5.37 µg 100g-1) was observed. Sensory qualities of the product decreased slightly with the advancement of storage period and osmo dehydrated red banana rings recorded the highest consumer acceptance followed by chunks and round shaped slices. No microbial growth was found till the end of storage.
In the present study, process variables were standardised for the development of osmo dehydrated red banana. Sugar syrup as osmotic solution at a concentration of 80oBrix with an immersion time of 180 min was recorded as the best treatment for osmo dehydration for all the three shapes of red banana slices viz., ring, round and chunks. Better consumer acceptability was recorded for osmo dehydrated red banana rings followed by chunks and round slices. Storage stability studies revealed that osmo dehydrated red banana packed in 200 gauge polypropylene could be stored for four months at room temperature without loss in quality.