食物与营养失调杂志

Physico-Chemical Analysis of Different Jams and Marmalade Prepared at Ari (Tarnab) Peshawar

Ateeq Ahmad, Zia-ud-din and Arsalan Khan

Jams are made from fruit and sugar mixed in proportion so that the final product contains a minimum fruit content of 35% and 60° Brix minimum. The research work was on physico-chemical analysis and storage stability of different fruit jams and marmalade stored at ambient temperature. The research was conducted at ARI, Tarnab, Peshawar in the lab of Food technology section. The aim of the study was to study the physico-chemical characteristics and the effect of storage stability of different fruit jams and marmalade stored at at room temperature (18? to 25?). All the samples to, which represents (apple jam), T1 which represents (guvava jam), T2 which represents (mixed fruit jam) while T3 which represents (citrus marmalade) were stored in sterilized glass jars and evaluation was carried out for total period of 60 days. Physico-chemical analysis; pH, TSS, acidity, moisture and sensory characteristics of color, taste, texture and overall acceptability (using Larmond scale) were evaluated at 15 days intervals. The results indicated that there was significant increase (P<0.05) in TSS of To (59.3° brix-62.7° brix), T1 (62.5° brix- 63.7° brix), T2 (63.4° brix-66.6° brix), T3 (59.4° brix63.2° brix), acidity of To (0.66-0.82), T1 (0.69-0.78), T2 (0.68-0.76), and T3 (0.86-1.35). While, significant decrease (P<0.05) were examined in pH of To (3.36-3.22), T1(3.26-2.98), T2 (3.27-3.14), and T3 (3.17-2.76). The moisture content of To (36.8%-35.3%), T1 (37.57%-35.76%), T2 (37.32%-34.8%), and T3 (39.2%-35.3%) was observed, whereas colour value of To (8-7), T1 (7-7),T2 (9-6), and T3 (8-8), taste value of To (7-7), T1(8-6), T2 (9-8), and T3 (8-6), texture value of To (8-7), T1 (7-6), T2 (8-7.5), and T3 (8-6.5), and overall acceptability value of To (8-7), T1 (8-5), T2 (9-8), and T3 (8-5) were noticed. Statistical results concluded that the treatment T2 (mixed fruit jam) was found most acceptable in terms of physicochemical and organoleptically as compared to To, T1 and T3. This study demonstrated that refrigeration storage was the best method to preserve the jam sample as compared to ambient storage temprature for the maintenance of product quality of different jams and marmalede.