Sensory, quality and biochemical attributes of pomegranate juice as affected by method of extraction

The study aimed to investigate the effect of different extraction methods on the sensory, quality and biochemical attributes of pomegranate juice. Pomegranate juice of 'Wonderful' cultivar, was extracted by 1) using a juice extractor to extract juice from arils without crushing the seeds, 2) using a blender and crushing the arils with the seeds and 3) using a commercial hand press juice on a halved pomegranate fruit. An untrained sensory panel of 33 people, evaluated the degree of intensity of sweetness, sourness, astringency, flavour and colour (1 = none; 5 = very intense) of pomegranate juice, as well as the degree of acceptability of colour, appearance and overall acceptability (1 = dislike extremely; 5 = like extremely). Pomegranate juice extracted by method 3 had a lower TA (0.74% citric), higher TSS: TA ratio (22.29), lower pH level (3.31) and high vitamin C concentration (196.16 mg AAE 100 mL(-1)). The TSS correlated negatively (r(2)=-0.75) with the sweet taste (p=0.05) during the sensory evaluation. The physicochemical results showed the extraction methods did not significantly influence the TSS content and juice colour absorbance (p>0.05), although sensory evaluation showed an affinity towards the juice colour (4.12) obtained by method 3. Discriminant analysis also showed that the juice colour distinguished method 3 from the other extraction methods. Method 3 scored highest for overall appearance (4.05), bitterness (2.14) and astringency (2.36), and method 1 for sourness. There were no significant differences (p>0.05) on the overall acceptability of all the extraction methods. Despite the method of extraction, all juice types appealed strongly to the consumers.