Impact of dehydration methods on the yield and quality of lime peels pectin

الملخص EN

Following the extraction of juice from lime fruits, the peels are dried and utilized in the production of pectin.

Different dehydration methods are used to dry lime peels.

These methods have great impact on the yield and the quality of the resultant pectin.

The aim of this study was to investigate the effect of drying methods (hot air oven, microwave and Instant Controlled Pressure Drop (DIC) on the chemical composition of lime peels, and the extracted pectin.

The results showed that DIC dried lime peels had the highest moisture content (12.80% ), ash content (4.58% ) and fiber content (26.83% ).

The highest pectin yield (25.77% ) was obtained from the DIC dehydrated lime peels.

The ash content of pectin samples ranged from 2.61% to 3.0% .

Pectin extracted from DIC dried peels (DP) had the highest galactuornic acid content (86.82% ).

Degree of esterification of extracted pectin was 69.18% , 67.90% and 68.50% for oven dried lime peels (OP), microwave dried lime peels (MP) and DIC dried lime peels (DP), respectively.

Therefore, all pectin samples were classified as high ester pectin.

The extracted pectin samples were used to make strawberry jam and compared to commercial pectin.

The results showed also that viscosity values of jam made by extracted pectin were higher than jam made by commercial pectin.

The highest value of viscosity was found in jam made with oven pectin (OP) being 480 cp, thenjam with DIC pectin (DP) being 472 cp, and then jam with microwave pectin (MP) being 450 cp.

Sensory evaluation of jam samples showed that jam made with (DP) had the highest score in respect to colour and texture.

Strawberry jams made with OP and DP were characterized by the highest score in respect to odour, taste and over all acceptability.