MSc

Kokum is an important indigenous, underutilized fruit cum spice crop that originated in the Western Ghats of India. It belongs to the family Clusiaceae (Syn. Guttiferae). Locally, the fruit is called Birand (Konkani), Murugalu (Kannada), or Punarpuli (Malayalam) and is known as the "cool king" of Indian fruits. The rich bioactive profile of kokum makes it an ideal choice in healthy diets and the fruit is mainly used for culinary purposes. The shelf life of the fruit is about one week. The quality of kokum products and the shelf life of fruits are known to be influenced by several physiochemical changes during the fruit growth period. Hence, it is vital to study the physical and chemical changes during the fruit development to facilitate adopting strategies that address problems related to fruit management, harvest, quality, and preservation. In this context, the study was conducted in two experiments: physiochemical changes in different phenological growth stages of kokum fruit and the development of value-added products from kokum. The first experiment evaluated physiochemical characteristics and organic acids at eight stages of fruit growth, development and maturity. Significant variation was observed in the physical properties at all the stages of fruit development in both genotypes. The fruit weight increased from 1.86g (P1) to 29.51g (P8). The maximum fruit breadth was at stage P8 (3.61 cm). The fruit length (0.60 cm) was minimum at the fruit set stage (P1) and increased significantly to 3.27 cm at stage P8. The fresh rind weight gradually increased from the fruit set (P1) to the final stage of harvest (P8). The maximum fresh rind weight was at stage P8 (13.39 g), whereas the dried rind weight was at stage P7 (1.86 g). Rind thickness gradually increased from 0.20 mm (P1) to 2.41 mm (P7). The rind percentage gradually increased from stages P1 (19%) to P8 (45.28%). The sour genotype was superior in all the parameters when compared to sweet genotype. Significant differences were also observed in the chemical properties, such as moisture, acidity, TSS, total sugars, ascorbic acid, anthocyanin, and total phenols in the different phenological stages (P1-P8) of kokum fruit in both the genotypes. The main fruit quality characteristics, such as the total soluble solids (11.08 ºBrix), total sugars (6.58%), and TSS: acidity ratio (3.04), were the highest at stage P8. At the same time, ascorbic acid (39.34 mg/100mg), acidity (6.53%), and total phenols (3.21 mg/g) of the fruit were the highest at stage P1 (fruit set). The moisture content increased from P1 (74.82%) to P8 (80.90%). The anthocyanin content of kokum rind increased from 5.26 (P1) to 23.46 mg/100g (P8) during the development of the fruit. This is the first kind of report on Garcinia indica with respect to organic acid profiling of both sweet and sour genotypes at different phenophases and eleven organic acids were successfully identified and quantified. The content of each organic acid varied significantly from fruit growth to maturity, except for tartaric acid. It was interesting to notice that the levels of hydroxycitric acid (233.16 mg/g), citric acid (107.28 mg/g), malic acid (18.75 mg/g), malonic acid (9.40 mg/g), fumaric acid (0.84 mg/g), and maleic acid (0.58 mg/g) were highest in stage P6. In contrast, the levels of succinic acid (44.24 mg/g), pyruvic acid (8.78 mg/g), and tartaric acid (0.35 mg/g) were highest in the final stage of harvesting, i.e., stage P8, whereas, shikimic acid (0.92 mg/g) and lactic acid (0.22 mg/g) were highest at stages P5 and P7, respectively. In the second experiment, a total of four types of products, viz., kokum carbonated RTS (KCR), kokum non-carbonated RTS (KNCR), kokum groundnut chutney powder (KGCP), and kokum coconut chutney powder (KCCP) were standardized using kokum rind powder. The data of RTS beverages revealed that treatments KNCR4 (15% kokum juice with 15 ºB), and KCR4 (10% kokum juice with 17 ºB) were found superior to all chemical parameters compared to other treatments. In instant chutney powders, KGCP4 (8% kokum powder with 60% roasted groundnut powder) recorded significantly higher total sugars, acidity, and ascorbic acid compared to other treatments of KGCP. Significantly higher total sugars, acidity, total phenols, and antioxidant activity was in KCCP4 (8% kokum powder with 60% roasted coconut powder) than other treatments of KCCP. Among the different treatments of kokum products, the highest organoleptic score was observed in KNCR2 (47.10), KCR3 (50.36), KGCP2 (45.99), and KCCP2 (47.69) in respected products. The products under refrigerated storage were found superior regarding sensory and microbial qualities. The microbial load was within acceptable level in all products made from kokum. The present study revealed that fruits harvested at the final maturity stage (P8) possessed the maximum fruit size, sugars, anthocyanins, lowest acidity, which are essential criteria in determining the maturity of the fruits. Therefore, it is suggested to harvest fruits at their complete maturity stage (P8). Value-added products can be developed from kokum fruit that can be utilized during the off-season. Due to its seasonality, adding value to this fruit will enable consumers to use it throughout the year