The enzyme catalyses the o-hydroxylation of monophenol molecules in which the benzene ring contains a single hydroxyl substituent to o-diphenols (phenol molecules containing two hydroxyl substituents). It has an optimum pH of 6.7. It can also further catalyse the oxidation of o-diphenols to produce o-quinones. PPO causes the rapid polymerization of o-quinones to produce black, brown or red pigments (polyphenols) that cause fruit browning. The amino acid tyrosine contains a single phenolic ring that may be oxidised by the action of PPOs to form o-quinone.
Apart from these, mango wastes3, sugar beet wastes4, sunflower heads5, Roselle calyces6, dragon fruit7, watermelon rind8, cocoa husks9 and papaya wastes10 have been studied for alternate sources of pectin. M.L.Fishman et al11 studied the physical properties of pectin extracted from pomegranate peels, like intrinsic viscosity and molecular weight,
In addition, carbohydrates and lignin content of the plant residues have been reported in Table 2. Glucan was the dominate carbohydrate of the residues followed by xylan. In the case of the untreated seed cake, the lignin content was as high as 36.1%. 3.2 Pretreatment 3.2.1 Eruca sativa oil pretreatment Figure 1A shows the effects of esterification temperature and time on the FFA content of the pretreated Eruca sativa oil when a methanol to oil mass ratio of 0.4:1 was applied in the presence of 1 wt% sulfuric acid. The results showed that the reaction rate and yield were significantly influenced (See Table S1, Supporting Information) by both the reaction temperature and
A] ANTIOXIDANT ASSAYS In the past decade, strong attention was given to the antioxidant power of fruits as an indicator of its quality. This parameter is strictly proportional to the presence of efficient reactive-oxygen/radical scavenging phenolic compounds and other secondary metabolites. Highly reactive molecules (NO, O2-, HOO-) generated in biological systems are associated with initiation of degenerative diseases. The antioxidant can reduced this risk. Uncontrolled generation of free radicals together with reduced level of antioxidative vitamins and enzymes are considered to be main contributor to oxidative stress (Ellnain-Wojtaszek et.
resistance may provide an additional method for controlling faba bean diseases to be considered in an integrated diseases management. Geetha and Shetty (2002) reported the induction of resistance in pearl millet against downy mildew disease up on treating seeds of the highly susceptible cultivars of pearl millet with the plant activator benzothiadiazole (BTH) (CGA 245704), calcium chloride (CaCl2) and hydrogen peroxide (H2O2). 0.75 per cent BTH, 90 mM CaCl2 and 1.0mM H2O2 were efficient in managing the disease by giving 78 per cent, 66 per cent and 59 per cent protection respectively, against downy mildew disease. In vivo quantification of Sclerospora graminicola by an enzyme-linked immunosorbent assay confirmed reduced fungal biomass in plants induced for resistance. 2.11.
Hydropriming is known as a seed pre-treatment which increases antioxidant enzymes such as glutathione and ascorbate. These enzymes decrease the activities of lipid peroxidation in the stage of germination. As a result, increases the percentage of germination and improves seed performance under environmental as well as laboratory conditions. Seeds of Aegle marmelos (bael) were treated as following: (i) unsoaked seed (control); (ii) hydropriming for 48 h; (iii) hydropriming for 96 h and (iv) hydropriming for 144 h as T1, T2, T3 and T4, respectively. The seeds were soaked in distilled water at 26 oC except control.
Fruit firmness is the major limiting factor for marketing and storage life of mango fruit. Fruit softening during the ripening process were due to the changes of cell wall degrading enzymes such as polygalacturonase (PG), pectin methyeaterase (PME), pectin esterase, and cellulase (Mithcham, Gross & Ng, 1991). The results in this experiment revealed that, mango fruit treated with 2 mmol/l PUT showed an increased fruit firmness during storage time. It has been reported that application of polyamines enhances fruit firmness in different fruits, including plums (Davarynejad, Zarei, Nasrabadi, & Ardakani, 2015), apricot (Martinez-Romero et al., 2002), pomegranates
bonplandianum is having wide range of phytochemical compounds. Plant and leaves contain alkaloids sparsiflorine, crotoflorine, crotsparine, crotsparinine, proaporphine, isoquinoline dienone, N-methylcrotsparine and N-methylcrotsparinine. Leaves and stem contains ß-sitosterol and taraxerol, vomifoliol, ursolic acid and tetrahydroglazievine. Leaves also contain rutin. Seeds contain phorbol diesters, phorbol trimesters, cocarcinogen; alkaloid, 3-OMe-4, 6-di-OH-morphinandien-7-one and norsinoacutine .
The three hybrids are the most promising cultivars under study and development of the Fruits and Ornamental Section (FOCS), IPB-CSC, CA, UPLB. Equipment The Cole Palmer Spectrophotometer (Sarcelles, France) was used for the spectrophotometric measurement of the total sugar contents of the papaya fruits. The Imada® Push-Pull MF (Japan) instrument was used in measuring the fruit firmness. A hand-held refractometer (Atago Automatic Temperature Compensation ATC–1, Japan) was used in determining the total soluble solids (TSS) of the papaya fruits. In the digital photometric determination, a 14-Megapixel VR330 Olympus digital camera was used to capture digital images of the papaya fruit peel.
Remove damaged and deformed fruits. Carefully arrange fruits in bamboo baskets or boxes and store in a cool place at 12-13°C with 85-90% relative humidity. Under this condition, fruit storage life can be extended 2-3 weeks. Bitter gourd is sensitive to chilling and damage may occur if kept below 10°C. Do not store fruits at temperatures above 13°C, as this will result in yellowing and splitting of fruits.