Process optimisation and quality evaluation of cocoa based chocolates
| dc.contributor.advisor | Seeja, Thomachan Panjikkaran | |
| dc.contributor.author | Shahanas, E | |
| dc.contributor.author | KAU | |
| dc.date.accessioned | 2020-12-16T07:31:48Z | |
| dc.date.available | 2020-12-16T07:31:48Z | |
| dc.date.issued | 2019 | |
| dc.description | PhD | en_US |
| dc.description.abstract | Cocoa (Theobroma cacao) is a supporting crop to farmers due to its remunerative income, which forms the basis for one of the world’s most popular food products chocolate. The quality of final product depends upon the fermented dried beans. High free fatty acid content is a serious quality defect and reduces the economic value of the cocoa beans. Recently, the cocoa trade has assumed a more scientific position and a lot of emphasis are placed on the content of free fatty acid. A reduction in the free fatty acids level will definitely have a positive impact. As such there is a need for the farmers to carry more intensive research and to develop and technology for the standardisation of free fatty acid content in the processing stages of cocoa in both primary and secondary processing. The present study was undertaken to develop protocol for primary processing of cocoa beans based on free fatty acid content (<1.75 %), to standardise the time and temperature of chocolate making using machine and to evaluate the quality attributes and shelf life of the products. Cocoa fermentation was carried out with three different types of fermentation methods like basket, heap and sack method for the periods of 5, 6 and 7 days of fermentation with nine different treatments. The physico-chemical qualities of fermented cocoa beans were evaluated. The highest (84.99%) fermentation index or cut test score was recorded in heap method at seventh day of fermentation (T6). The highest fermentation bean recovery of 84.33% was noticed in treatment T4 in heap method at fifth day of fermentation. The moisture content vary from 50.40 %, 53.67% and 54.40% to 39.80%, 37.83% and 39.43% from initial to seventh day of fermentation in sack, heap and basket method respectively. The pH of fermented beans varied from 6.11 to 4.26 in all methods. Among the fermentation methods the maximum fat content was in heap method from initial 42.66% to 32.89%. The lipase activity, decreased with fermentation periods in all three fermentation methods. In heap method it varied from 0.0022 to 0.0005. The heap method with seven days of fermentation were selected to sun drying and oven drying based on the lowest free fatty acid content (0.80%). The bean recovery of fermented dried beans was high (41.00 %) in sun dried cocoa beans as compared to oven dried beans (40.12 %). The free fatty acid content (1.26 %) in sun dried cocoa beans was less compared to 1.47% in T2 (oven dried beans). The moisture content (3.76%) and lipase activity (0.0018μ eq) was less but, the fat content and pH was high in sun dried beans. The sun drying proved to be adaptive as free fatty acid content was lower than oven dried beans and were below the cut off value of 1.75%. The sun dried beans were stored in gunny bags (control), polythene covers and plastic containers under ambient condition for a period of six months and the physico-chemical qualities of stored cocoa beans were done initially and at an interval of one month for a duration of six months. The highest bean recovery (98%) and least moisture content (4.22 to 4.52) was in cocoa beans stored in plastic container at the end of sixth month of storage. The lowest free fatty acid content of 1.68% was in cocoa beans stored in plastic container at sixth month after storage. The stored cocoa beans in plastic container were divided into two lots, one lot was used as such and the second lot was subjected to alkalisation. The chocolates was prepared with alkalised and non alkalised cocoa beans in tempering and conching machine for different time periods of 7, 9 and 11 hours at a temperature of 600C and 700. After the preparation of different types of alkalised and non alkalised chocolates in tempering and conching machine, chocolates were subjected to analysis of physico-chemical qualities, organoleptic evaluation and for enumeration of microflora. The treatment T6 (Chocolate prepared at 700C for 11 hours) and T12 (700C for 11hours) had the lowest free fatty acid content of 1.67% and 1.68% and maximum score for overall acceptability (8.89 and 8,87). Chocolates prepared at 700C for 11 hours from alkalised and non alkalised beans were blended with dehydrated grapes, dehydrated dates, osmodehydrated jackfruit, osmodehydrated pineapple, badam, cashew nut, powdered dehydrated mint leaves and white pepper powder. From the, organoleptic evaluation of different treatments, the best rated treatments from alkalised chocolates were T3 (95 % alkalised chocolates +5% osmodehydrated jack fruit), T6 (95 % alkalised chocolates +5% badam) and T8 (95 % alkalised chocolates +5% white pepper) and from non alkalised chocolates the treatments T11 (95 % non alkalised chocolates +5% osmodehydrated jack fruit), T14 (chocolate blended with 95 % non alkalised chocolates and 5% badam) and T16 (95 % non alkalised chocolates and 5% white pepper powder) were selected, packed in aluminium foil and stored in refrigerator for six months. Initially the lowest hardness of 74.41N and 76.71N was recorded in controls (T0 - AC) and (T0 – NAC. The maximum energy content of 580.15Kcal was found in treatment T5 (95 % NAC+5% B). Initially the maximum protein content (7.74 g/100g) was noticed in treatment T2 (95 % AC+5% B) and T5 (95 % NAC+5% B). The highest polyphenol content ranging from 0.23g/100g to 0.19g/100g was seen in T0 (100% NAC) throughout the storage periods. A reduction in mineral contents like calcium, phosphorus and iron content was observed in all treatments and at the end of sixth month calcium content varied from 0.39g/100g to 0.63g/100g. An increase in lipase activity and free fatty acid content of blended chocolates was recorded during storage and FFA was within 1.75% up to fourth month of storage. Based on organoleptic score, the treatment T2 (95 % AC+5% B) attained the highest rank. The blended chocolates were evaluated for the presence of bacteria, yeast and mould initially and monthly intervals for a period of six months, At the end of sixth month of storage the highest bacterial count of 2.0 x 104 cfu/g was found and during sixth month of storage. The cost for blended chocolates was varied from Rs.46.54 to Rs.50.62 / 40 g of chocolate bar. The cost of the chocolates prepared in the present study was lesser as compared to the commercial chocolates. The present study found that good quality, nutritious and healthy blended chocolates using cocoa could be prepared without adding any preservatives. The blended chocolates contain treasure of nutrients and bioactive compounds polyphenol which is essential for the growth and development of children and also give several health benefits. | en_US |
| dc.identifier.citation | 174743 | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810156745 | |
| dc.keywords | Community Science | en_US |
| dc.language.iso | English | en_US |
| dc.pages | 248p. | en_US |
| dc.publisher | Department of Community Science, College of Horticulture,Vellanikkara | en_US |
| dc.sub | Horticulture | en_US |
| dc.theme | Quality evaluation of cocoa based chocolates | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | Process optimisation and quality evaluation of cocoa based chocolates | en_US |
| dc.type | Thesis | en_US |