RESULTS AND DISCUSSION
The discussion will cover the obtained results under the following heads:
1. Effect of some different parameters on the behavior of drying rate
Fig.1 showed the relation between drying rate and drying time under two drying methods of fruits peels. It was cleared that the drying rate decreased continuously with drying time. There was not any constant-rate drying period and all the drying operations are seen to occur in the falling rate period. The drying rates were higher at the beginning of the drying operation, when the product moisture content was higher. The moisture content of the material was very high during the initial phase of the drying. Concerning the effect of drying methods on drying rate,
Electric Oven
Microwave …show more content…
(2): Effect of fruit peels masses on drying efficiency and specific energy under the two drying methods
While, drying efficiencies in oven and microwave were (5.65 and 37.43%) of orange peels, (7.00 and 38.13%) of lemon peels, (6.76 and 39.20%) of pomegranate peels and (8.94 and 38.03%) of grapefruit peels, under the same previous conditions. This is in agreement with (Diaz et al., 2003).
Concerning the effect of fruit peels masses; results explained that increasing the peels masses; the specific energy decreased vice versa, drying efficiency was increased. Overall mass of evaporated water was increased by increasing peels masses and thereby the specific energy was decreased. The drying efficiency for fruit peels in a microwave were 17.63, 35.20, 37.43 and 39.66% for orange, 23.20, 30.51, 38.13 and 37.24% for lemon, 19.31, 39.00, 39.20 and 42.58% for pomegranate, while 25.65, 31.74, 38.03 and 36.14% for grapefruit under 50, 100, 150 and 200g, respectively.
3- Effect of different drying methods on product quality of fruit peels
Vitamin C, fiber content, essential oil and phenolic content in orange, lemon, pomegranate and grapefruit peels as shown in Table 2 were determined as an indicator for the quality of the dried …show more content…
B: Lemon peels. C: Pomegranate peels. D: Grapefruit peels.
Regarding to the effect of peels masses, results clarified that the optimum masses of drying peels were 50g in a microwave and 200g of peels in oven for different fruit peels.
It is observed that the use of higher peels masses in microwave, accelerate the evaporation of water with higher drying rates, that tends to lose some properties of the dried material which is reflected on the product quality.
While, drying the highest masses in oven took the required time of drying rate and thereby, the quality was improved.
4- Mathematical models
Non-linear regression was used to obtain each parameter value of every model. The results of statistical analyses undertaken on these models are given in Tables 3 and 4 at 50g for different fruit peels in oven and microwave, respectively.
It was noticed in the case of oven drying that Newton and Henderson and Pabis models showed good agreement with orange and lemon peels, while Page and Modified Page (I) gave the best descriptive models for
The discussion will cover the obtained results under the following heads:
1. Effect of some different parameters on the behavior of drying rate
Fig.1 showed the relation between drying rate and drying time under two drying methods of fruits peels. It was cleared that the drying rate decreased continuously with drying time. There was not any constant-rate drying period and all the drying operations are seen to occur in the falling rate period. The drying rates were higher at the beginning of the drying operation, when the product moisture content was higher. The moisture content of the material was very high during the initial phase of the drying. Concerning the effect of drying methods on drying rate,
Electric Oven
Microwave …show more content…
(2): Effect of fruit peels masses on drying efficiency and specific energy under the two drying methods
While, drying efficiencies in oven and microwave were (5.65 and 37.43%) of orange peels, (7.00 and 38.13%) of lemon peels, (6.76 and 39.20%) of pomegranate peels and (8.94 and 38.03%) of grapefruit peels, under the same previous conditions. This is in agreement with (Diaz et al., 2003).
Concerning the effect of fruit peels masses; results explained that increasing the peels masses; the specific energy decreased vice versa, drying efficiency was increased. Overall mass of evaporated water was increased by increasing peels masses and thereby the specific energy was decreased. The drying efficiency for fruit peels in a microwave were 17.63, 35.20, 37.43 and 39.66% for orange, 23.20, 30.51, 38.13 and 37.24% for lemon, 19.31, 39.00, 39.20 and 42.58% for pomegranate, while 25.65, 31.74, 38.03 and 36.14% for grapefruit under 50, 100, 150 and 200g, respectively.
3- Effect of different drying methods on product quality of fruit peels
Vitamin C, fiber content, essential oil and phenolic content in orange, lemon, pomegranate and grapefruit peels as shown in Table 2 were determined as an indicator for the quality of the dried …show more content…
B: Lemon peels. C: Pomegranate peels. D: Grapefruit peels.
Regarding to the effect of peels masses, results clarified that the optimum masses of drying peels were 50g in a microwave and 200g of peels in oven for different fruit peels.
It is observed that the use of higher peels masses in microwave, accelerate the evaporation of water with higher drying rates, that tends to lose some properties of the dried material which is reflected on the product quality.
While, drying the highest masses in oven took the required time of drying rate and thereby, the quality was improved.
4- Mathematical models
Non-linear regression was used to obtain each parameter value of every model. The results of statistical analyses undertaken on these models are given in Tables 3 and 4 at 50g for different fruit peels in oven and microwave, respectively.
It was noticed in the case of oven drying that Newton and Henderson and Pabis models showed good agreement with orange and lemon peels, while Page and Modified Page (I) gave the best descriptive models for