Quality assessment of promising garlic (Allium sativum L.) varieties based on principal component analysis

Abstract

Physicochemical properties, pungency, anti-nutritional factors, cutting strength, and colour attributes of seven promising garlic varieties were assessed for their potential application. The garlic varieties were found to be slightly acidic (pH 6.08 - 6.77), and contained varying amounts of crude protein, carbohydrate, crude fat, ash, crude fibre, acidity, and total soluble solids (TSS). The pungency factor as pyruvic acid was found to be in the range of 34.84 - 86.69 μmol/mL, whereas anti-nutritional factors such as saponin (6.63 - 13.98 g), phytic acid (0.03 - 0.6 g), and tannin (0.18 - 0.39 gCE) per 100 g on a fresh weight basis were present. The Bhima purple (BP) variety with a purple tinge showed higher saponin content than the other varieties with a whitish tinge. The cutting strength of garlic cloves varied between 17.20 and 104.61 N. Physical and gravimetric properties were estimated and found to be variety-dependent (p ≤ 0.05). Colour attributes like L* (lightness), a* (redness), b* (yellowness), chroma, hue, and browning index were significantly different (p ≤ 0.05) for all the garlic varieties. The minimum hue value, and maximum a* and b* values, browning index (BI), and chroma were found in the BP variety. Principal component analysis as a significant multivariate analysis tool was applied to assess the existence of correlation among the estimated parameters. It was found to be 75.41% of the total variance when considering the first three principals. Haryana garlic-17 (HG-17) variety showed significant quality as it yielded positive correlation with the maximum number of quality attributes.