Physicochemical analyses were carried out for 15 days of intervals during 90 days of storage period. Chemical preservatives and antioxidants mixed in different concentrations were added to the pulp and packed in plastic containers, stored at room temperature. The treatments were T o (apple pulp), T 1 (apple pulp + 0.1% sodium benzoate + 0.1% citric acid), T 2 (apple pulp + 0.1% sodium benzoate + 0.5% citric acid) and T 3 (apple pulp + 0.1% potassium metabisulphite + 0.1% citric acid). The samples were studied for ascorbic acid, % acidity, pH, total soluble solids (TSS) and sugar acid ratio. A decrease was recorded in ascorbic acid content (18.96 to 12.93 mg/100g), sugar acid ratio (30.96 to 27.62), pH (3.59 to 3.25), while an increase was recorded in titratable acidity (0.32 to 0.41), TSS (9.75 0 Brix to 11.39 0 Brix). During organoleptic evaluation samples T 3 was found most acceptable during storage. Statistical analysis showed that storage intervals and treatments had a significant (P<0.05) effect on physico-chemical analysis of apple

Background Longan fruit is a rich source of bioactive compounds; however, enzymatic browning of pericarp and microbial decay have limited its postharvest life. SO2 has widely been used to overcome these limitations; however, due to safety and regulatory concerns, alternative means should be identified. In this study, antioxidant and antimicrobial properties of thymol (TH) essential oil were investigated against the enzymatic browning and decay of longan fruit. Methods Fruits were coated with TH (4%) for 5 min, sealed in polyethylene (PE) packages and stored at 4 °C for 42 d. Fruits immersed in distilled water (DW) and stored in PE were used as control. Results TH extended the postharvest life of longan to 42 d than 28 d in DW. TH residues decreased from 142 to 11.17 mg kg–1, while no residues were found at day 42. TH significantly (P ≤ 0.05) reduced the respiration rate, inhibited polyphenol oxidase (PPO) and peroxidase (POD) enzyme activities, sustained high phenols/flavonoids and prevented pericarp browning (BI) than DW. TH also effectively (P ≤ 0.05) maintained the color values, firmness of peel and aril, total soluble solids (TSS), titratable acidity (TA), inhibited decay incidence (DI) and resulted in lower ethanol content than DW. BI as a function of pericarp pH was highly correlated; pH and BI (r = 0. 97), with PPO (r = 0.93) and with water loss (r = 0.99). A high coefficient of correlation of BI was found with the pericarp pH, enzymes, phenolic, water loss and decay incidence with ethanol. TH could be the best alternative to SO2 and other synthetic preservatives.

Citral (3, 7-dimethyl-2, 6-octadienal)was hydro distilled from lemon grass and 3, 7-dimethyl-2, 6-octadienal acetals (Citral acetals) were synthesized from it. The latter was redistilled under vacuum and collected fractions at constant temperature. Para toluene sulphonic acid catalyst was used for the preparation of citral ethylene glycol acetal and citral propylene glycol acetal which are used in perfumery, flavor, for fortifying lemon oil. GC, IR of synthesized product is recorded and graphs were determined.

The study was aimed to identify the physicochemical and sensory changes of strawberry and dates blend ready to serve drink in storage of three months with gap of 15 days at room temperature (25-30 0 C). Strawberry and dates juice blend ready to serve drink were formulated as SDB1 = 9:1, SDB2 = 8:2, SDB3 = 7:3, SDB4 = 6:4 and SDB5 = 5:5 by addition of sodium benzoate (0.01%) in each treatment as preservative and mixed 20% of each combination with 10 0 brix sugar solution of calculated value. The samples were analyzed physicochemically (pH, vitamin C, TSS, % acidity, reducing sugar, non-reducing sugar and sugar acid ratio) as well as organoleptically (flavor, color, taste and overall acceptability). Outcomes of experiments showed a mean of total soluble solids of strawberry and dates blend ready to serve drink upgraded from 13.05 to 13.89°brix. % acidity of blend enhanced from 0.71 to 0.95, reducing sugar increased from 9.29 to 10.91, whereas pH was reduced from 4.66 to 3.82, ascorbic acid value was declined from 48.67 to 31.51, non-reducing sugar decreased from 4.02 to 2.90 and sugar acid ratio declined from 20.23 to 14.77. Sensory evaluation showed that mean scores for color of strawberry and dates blend ready to serve drink were reduced from 8.36 to 5.10, flavor decreased from 8.15 to 5.21, taste reduced from 8.11 to 5.11 and overall acceptability also declined from 8.21 to 5.14 during storage. From this research it was concluded that SDB3 (Strawberry and date juice blend in ratio (7:3) + 0.01% sodium benzoate) found finest among all other combinations of ready to serve drink.

No abstract