Effect of Different Drying Conditions on Proximate Compositions of Red- and Yellow-Fleshed Watermelon Rind Powders

Abstract

This study aimed to investigate the effect of different drying conditions (hot-air oven drying at 40 â°C and 60 â°C, and freeze drying) on nutritional quality of red- and yellow-fleshed watermelon rinds. The proximate compositions, carbohydrate content, and energy value of watermelon rind powders were determined. Freeze drying method preserved more nutrients followed by hot-air oven drying at 40 â°C and 60 â°C for red-fleshed watermelon rind powder. The freeze dried powder contains 18.86% moisture, 19.13% ash, 11.82% crude protein, 22.02% crude fiber, 2.21% crude fat, 47.77% carbohydrate, and 259.13 kcal of energy. Hot-air oven drying at 40 â°C was the most effective method to preserve the nutrient of yellow-fleshed watermelon rind powder with chemical compositions of 15.12% moisture, 20.57% ash, 13.37% crude protein, 14.34% crude fiber, 0.70% crude fat, 50.31% carbohydrate, and 260.72 kcal of energy. Results suggest that freeze drying and hot-air oven drying (40 â°C) methods had the highest potential to be applied in processing of red- and yellow-fleshed watermelon rind powders, respectively.

 

Keywords: Freeze drying, hot-air oven drying, proximate composition, watermelon rind powder

 

ABSTRAK

 

Kajian ini bertujuan untuk mengkaji kesan daripada keadaan pengeringan yang berbeza (pengeringan oven udara panas pada suhu 40 â°C dan 60 â°C dan pengeringan sejuk beku) terhadap kualiti nutrien kulit buah tembikai berisi merah dan berisi kuning. Komposisi proksimat, kandungan karbohidrat, dan nilai tenaga kulit buah tembikai telah dikenalpasti. Pengeringan sejuk beku didapati mengekalkan lebih banyak nutrien diikuti dengan pengeringan oven udara panas pada suhu 40 â°C dan 60 â°C untuk kulit buah tembikai berisi merah. Tepung pengeringan sejuk beku mengandungi 18.86% kelembapan, 19.13% abu, 11.82% protein mentah, 22.02% serat mentah, 2.21% lemak mentah, 47.77% karbohidrat dan 259.13 kcal tenaga. Pengeringan oven udara panas pada suhu 40 â°C adalah kaedah yang paling berkesan bagi mengekalkan nutrien kulit buah tembikai berisi kuning dengan komposisi kimia 15.12% kelembapan, 20.57% abu, 13.37% protein mentah, 14.34% serat mentah, 0.70% lemak mentah, 50.31% karbohidrat dan 260.72 kcal tenaga. Hasil kajian menunjukkan kaedah pengeringan sejuk beku dan pengeringan oven udara panas (40 â°C) adalah memiliki potensi terbesar untuk digunakan dalam pemprosesan tepung kulit buah tembikai berisi merah dan berisi kuning, secara berurutan.

 

Kata kunci: Pengeringan sejuk beku, pengeringan oven udara panas, komposisi proksimat, tepung kulit buah tembikai