PERFORMANCE EVALUATION OF SOLAR DRYER (HYBRID) AND RF STERILIZER FOR COPRA DRYING TO EXTEND STORABILITY C.S.Vidhya, R. Meenatchi*. Indian Institute of Food Processing Technology, Ministry of Food Processing Industries, Government of India, Pudukkottai Road, Thanjavur – 613 005 *meena@iifpt.edu.in
ABSTRACT To evaluate the performance of Solar dryer and Radio Frequency sterilizer as a potential source for drying of copra at 580C(SD) and 650C(RF) to extend its storability and to assess the microbial activity. The treatment was carried out at various combinations of belt speed and electrode heights in order to get the reduced moisture content that can be achieved using the Radio Frequency setup and various temperatures in Solar dryer. It was observed that the rate of moisture content decreased from 58.95– 25.26% and initial relative humidity decreased from 84% to 26% in a temperature range of 650C and the variation in electrode height from 200 to 270 mm in RF sterilizer and in Solar hybrid dryer initial relative humidity decreased from 84% to 54% in a temperature range of 580C,initial moisture content 58.95% was reduced to 30.53%.Therefore, RF and Solar hybrid dryer holds potential to scale up to industrial applications in drying of copra which helps in reduced microbial spoilage and extends shelf life.
AIM:
• • •
TABLE 1
To dry copra using the solar hybrid dryer and RF sterilizer. To use various temperatures to reduce moisture content in copra. To reduce microbial spoilage and extend shelf life of copra.
OBJECTIVE: • Copra is the dried meat, or kernel of the coconut. • Solar hybrid dryer designed by IIFPT is used to dry copra , • The drying of copra in the solar drier had a reduced moisture content and relative humidity at 580c. • RF sterilizer had a reduced moisture content at 650c. in copra • EXPERIMENTAL SETUP/MATERIALS & METHODS .
•
Control and dryers
Temperature (0c)
Moisture content(%)
Relative humidity (%)
Fresh copra
30
58.95
84
Solar dryer
58
30.53
54
RF Sterilizer
65
25.26
26
26 Relative humidity (%)
54
Coconut (Cocos nucifera) drying by using solar energy is the
84
traditional method practiced in India.
•
25.26
But spoilage due to weather conditions causes liability during
Moisture content (%)
30.53 58.95
drying.
•
An attempt was made to dry copra using RF sterilizer at 50 0c
65 Temperature (˚C)
•
&65 0c and Solar dryer 53 0c, 58 0c & 63 0c.
•
Different temperatures used reduced the moisture content and
58
30
0
10
20
30 RF Sterilizer
microbial activity and the quality of the copra were assessed.
40 Solar dryer
50
60
70
80
90
Fresh copra
Comparison of RF sterilizer, Solar dryer treated copra with Control sample
. .
CONCLUSIONS
• • Solar Hybrid dryer
RF Sterilizer
RESULTS AND DISCUSSIONS
• •
The solar dryer was used for copra drying at temperature 580c showed reduced relative humidity from 84% to 54% and moisture content 58.95% reduced to 30.53% . RF sterilizer electric post range from 200-270mm and oven temp of 650c showed marked decrease in moisture content from 58.95% to 25.26% and relative humidity from 84% to 26% which helps in reduced spoilage and extended shelf life of copra.
The solar hybrid dryer and RF sterilizer were proved to be effective in reducing the moisture content of copra. Reduced fungal colonies were observed in both RF and Solar hybrid dryer treated copra.
REFERENCES
• • •
Garbati Pegna, F., Saccheti, P et al, 2017 Radio frequency irradiation treatment of dates in a single layer to control Carpopilus hemipterus. Biosystems Engineering, 155:1-11. Nathavel, W.R.N. 1965. Some aspects of copra deterioration. Coconut Research Institute of Ceylon.16:111-120. Kellert.1996. Drying characteristics of copra and quality of copra and coconut oil. Postharvest Technology. 9(3): 361-372.