Optimisation of ultrasound-assisted osmotic dehydration of sweet potato (Ipomea batatas
) using response surface methodology

Abstract Eucalyptus deglupta is one of the promising medicinal plants from Mytracea family consisting of bioactive compounds that are to be used in medications. The bioactive compounds present in Eucalyptus deglupta were extracted at the best yield using a hybrid drying method consisting of ultrasound assisted osmotic dehydration (UOAD) and hot air drying in this study. The drying conditions of UAOD were optimised with response surface methodology (RSM) to attain the highest antioxidant activity via of DPPH radical scavenging assay. Four parameters were optimised with response surface methodology, namely concentration of sucrose (v/w), temperature (°C), duration of drying and intensity of ultrasound (%) ranged from 30% to 50%, 20°C to 60°C, 40 min to 100 min and 60% to 100%, respectively. A series of 27 combinations of the UAOD drying conditions were performed and followed by hot air drying performed at 60°C until a constant weight was achieved. A moderate scavenging activity of DPPH assay (56.12%) was achieved at a concentration of sucrose, temperature, duration of drying and intensity of ultrasound of 50%, 40°C, 100 min and 264 W, respectively.

Download Full-text

Evaluation and Optimization of Steam and Lye Peeling Processes of Sweet Potato (Ipomea batatas) using Response Surface Methodology (RSM)

International Journal of Food Engineering ◽

10.1515/ijfe-2013-0051 ◽

2014 ◽

Vol 10 (2) ◽

pp. 329-338 ◽

Cited By ~ 4

Author(s):

Ayobami O. Oladejo ◽

Olajide P. Sobukola ◽

Samuel O. Awonorin ◽

Samuel B. Adejuyigbe

Keyword(s):

Response Surface Methodology ◽

Sodium Hydroxide ◽

Response Surface ◽

Surface Area ◽

Sweet Potato ◽

Process Parameters ◽

Sodium Hydroxide Concentration ◽

Independent Variables ◽

Ipomea Batatas

Abstract Sweet potato of uniform sizes and shape were subjected to steam peeling (temperature 80–100°C and peeling time 5–15 min) and lye peeling (sodium hydroxide concentration 8–12%, temperature 80–100°C and peeling time 3–5 min). Response surface methodology was used to analyze and optimize the process parameters in each case. For steam peeling, the peel loss and unpeeled surface area were 6.85 and 28.16%, respectively, while optimum peeling conditions where temperature and peeling time of 100°C and 5 min, respectively, for minimum peel loss and unpeeled surface area. For lye peeling, however, the peel loss and unpeeled surface area were 13.19 and 13.35%, respectively, and optimum peeling conditions were lye concentration, temperature and peeling time of 8.89%, 100°C and 4.75 min, respectively, for minimum peel loss and unpeeled surface area. The models developed in each case (R-squared of 0.9225 and 0.8428; 0.5929 and 0.8346) were adequate in producing responses as a function of the independent variables. From the optimized values and results obtained, lye peeling was more suitable for sweet potato.

Download Full-text