Borthakur, Pritom K.Saikia, Kareena2024-07-052024-07-052023https://krishikosh.egranth.ac.in/handle/1/5810211505Ten genotypes representing each of the five groups of Citrus were collected from AAU-Citrus and Plantation Crops Research Station, Tinsukia and Regional Research Centre for Citrus (CCRI, ICAR), Biswanath Chariali. Morphological characterization of fruits was carried out as per the descriptors developed for Citrus by IPGRI (1999), Rome, Italy and the results indicate the presence of significant variability among genotypes. Biochemical characterization revealed that moisture content ranged from 92.51% to 84.30% in the pulps and from 83.32% to 70.20% in the peels. Juice pH, TSS and titratable acidity ranged from 3.90 to 2.60, 11.40 to 5.30 ̊Brix, and 0.97% to 4.71% respectively in different genotypes. The ash content varied from 2.83% to 5.96% in the pulps and from 2.53% to 5.69% in the peels. Similarly, the reducing sugar in the juice varied from 2.06% to 6.72% and non-reducing sugar varied from 0.48% to 4.15%. The total sugar percentage ranged from 9.36%-2.54% in the juice. The crude protein content was found to be high and ranged from 5.60%-9.16% in the pulps and 5.60%-13.83% in the peels. Organic acid and water-soluble vitamins were quantified using Ultra High-Performance Liquid Chromatography (UHPLC) and it was revealed that citric acid was present in the maximum amount followed by malic acid. Among the water-soluble vitamins, the thiamine concentration was found to be the highest. Quantification of the minerals was carried out by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results show that both major and minor minerals were present in significant amounts in both the peel and pulp of the Citrus species. The essential oil content (%) was estimated and it was found to range from 0.26% to 0.83% in the fresh peel of the Citrus genotypes. Analysis of the essential oil that was carried out by Triple Quadrupole Gas-Chromatograph Mass-Spectroscopy (TQGC-MS/MS) showed the presence of D-limonene, α-pinene, ß-pinene, γ -terpinene, α-terpineol, terpinene-4-ol, linalool as the major compounds. Aromatherapeutic, antioxidant, antifungal and insect-repellent compounds such as eucalyptol, thymol, geraniol and nerol were also reported in certain species.EnglishThesis