Assessment of greenhouse technologies on the drying behavior of cocoa beans

Effect of Modified Greenhouse Drying Technology on the Physicochemical Quality of Cameroonian Cocoa Beans

Several benefits give credence to the importance of maintaining the reference values of the physicochemical properties of cocoa beans at all stages along the cocoa chain. Every drying method confers significant effects on quality with implications on demand and prices. In this work, the modified greenhouse dryers were tested as potential equipment for the production of high quality cocoa beans. To ascertain their validity for use in the cocoa chain, moisture content, pH, free fatty acid, total polyphenol, peroxide value, total phenols, condensed tannins, and flavonoids were investigated. In relation to reference values, all the samples were of good quality. In terms of moisture content, pH, total acidity, free fatty acid, total polyphenol content, phenol content, flavonoids, and peroxide value, the samples fell within the acceptable values. Total phenols, flavonoids, and condensed tannins were within the recommended range. Samples dried in the open sun dryer and modified greenhouse dryer with fleece of cotton presented the highest amounts of total phenols, flavonoids, and condensed tannins. For total fat content, the samples dried in modified greenhouse dryers equipped with fleece of polyester and the conventional greenhouse dryer were distinctly of grade one quality.

A Review of Cocoa Drying Technologies and the Effect on Bean Quality Parameters

Considering drying as a key farm-based, quality determining unit operation in the cocoa processing chain, this paper reviews recent studies in the drying methods and quality parameters of cocoa beans. Open sun, solar, oven, microwave, and freeze drying methods have been investigated at various levels in the drying of cocoa beans with objectives to improve the drying properties and final quality of cocoa beans. While an open sun dryer employs natural passive mechanisms, the solar drying methods can employ a combination of passive and active mechanisms. The oven, microwave, and freeze drying methods are fully active requiring electrical energy inputs. To improve drying rates in the open sun method, dryer materials and location of drying trays are the parameters optimized since the drying temperature depends on solar intensity. For solar dryers, materials, angles of elevation, heaters, and fans are manipulated to optimize energy absorption and drying parameters. For the oven and microwave methods, drying air properties are directly controlled by electronic systems. Moisture content, mouldiness, bean colour, pH, titratable acidity, fat content, and acetic acid concentration are the most widely evaluated bean quality parameters.

Monitoring and Optimization of Cupuaçu Seed Fermentation, Drying and Storage Processes

Cupuaçu [Theobroma grandiflorum (Wild ex Spreng.) K. Schum] seeds have been employed for a long time in the Amazon region for food purposes. Similar to cocoa, processed cupuaçu pulp and seeds can be used to produce juices, ice creams, confectionary products and cupulate®, which is a similar product to chocolate. However, its market penetration requires the mastery of all processing stages to improve the food quality and safety and to make possible an efficient technology transfer to the local small farmers and communities. Based on the above, the current research work aimed at monitoring and optimizing the consecutive fermentation and drying processes of cupuaçu seeds over 7 days each, as well as storage for 90 days. A greenhouse structure incorporating the fermenter and solar drying terrace was designed to be inexpensive, versatile, easily scalable, and easy to maintain and operate by the local small farmers after a short period of training. This research effort also aimed at giving a vision for the future creation of an integrative and sustainable cupuaçu system covering the economic, social, cultural and environmental vectors. The experimental design comprised 5 batches of 100 kg of seeds each. Several microbiological and physicochemical parameters were performed and correlated with processing variables. Microbiological parameters encompassed viable counts of mesophilic microorganisms, coliforms, yeasts, and molds, whereas physicochemical measures included fermentation and drying temperature, pH, acidity, dry matter, ashes, water activity, color, total proteins, lipids and carbohydrates, and energy. The average seed fermentation temperature varied from ca. 28 to 44 °C, reaching the maximum on day 3 and a final value of ca. 31 °C. Regarding solar drying, the average seed temperatures ranged from ca. 24 °C (at the end) to 39 °C on day 3, and an initial value of ca. 29 °C. The average final seed pH value of drying was 5.34 and was kept during storage. During storage, results demonstrated the existence of significant correlations among several experimental parameters under scrutiny. Finally, bean viable counts obtained during storage unfolded acceptable values of total mesophilic bacteria well below the maximum limit. Viable counts of yeast and molds were generally found between 3 and 4 log(CFU/gsample), and total coliforms were also detected, although both were at acceptable levels and well beneath the established maximum limits for food safety.