Prospective Investigation of Hurdle Technology to Combat Post Harvest Losses of Peach Fruit

Abstract

Peach (Prunuspersica L.) is an important stone fruit of the temperate zone of the globe. It is a nutrient-dense fruit containing important health promoting constituents. The short postharvest life of fresh peach is a main bottleneck in supplying the fruit to national and international markets. Chilling injury is another limiting factor in the post-harvest life of fruit during the cold storage. Keeping in view the economic importance of the fruit and huge postharvest losses, the present research study was designed in three phases. Late maturing variety Indian Blood "Swat No. 8" was selected for the research. The fruits were stored at 0±1°C with 85–90% RH during the period of analysis. The data regarding various parameters were recorded at 10 day intervals up to 40 days of storage intervals. In experiment No.1 (first phase),fruits were treated with hot water to optimize the suitable hot water temperature and the optimized water temperature was50°C, that was used for all other treatments of second and third phases of this investigation. Physicochemical analysis(moisture content, total soluble solids(TSS), weight Loss, pH, acidity, sugar acid ratio, reducing sugar content, non-reducing sugar content, vitamin C content, beta carotene content , total phenolic content, ash, phosphorus, potassium, magnesium, calcium, flesh firmness, water activity, chilling injury and decay index), microbial analysis(total bacterial count (TBC), total fungal count(TFC), brown rot (Monilinia fructicola), Rhizopus rot(Rhizopus stolonifer), gray mold (Botrytis cinerea) and sensory analysis(colour, flavour, texture, juiciness and overall acceptability) of the treated and non-treated (control) peaches were performed to optimize the hurdle conditions to preserve the physical and nutritional quality for a longer period in storage.. On the basis of overall quality characteristics,T4(peaches with hot water treatment at 50°C) was selected for research. The second phase consisted of three experiments. In experiment No.2, 1-MCP, CaCl2 and salicylic acid was use alone and in combinations. Fruits were analyzed for physicochemical microbial and sensory properties at 10 days intervals for 40 days during the cold storage.1-MCP + CaCl2 maintained good qualities of the peaches by lowering chilling injury and microbial loads and with higher sensory attributes up to 40 days of storage followed by 1-MCP + salicylic acid. In experiment No.3, hot water and chemicals treatment optimized in the previous experiment was used for rest of the experiments. In this experiment, hot water (500C) was used in combination with 1-MCP, CaCl2 and salicylic acid. The combined effect of the best selected treatments (Hot water+ 1-MCP(500 μg L -1 ) + CaCl2(3%)followed by hot water + 1-MCP (500 μg L -1)+ salicylic acid (0.10 g/L ) exhibited good results to keep the qualities of peaches for 40 days in cold storage. In experiment No.4, aloe vera wax and sulfur dioxide fumigation were used alone and in combinations. The samples were analyzed for physicochemical, microbial and sensory attributes at10 days intervals for 30 days in cold storage. The best result was observed when the fruits were treated with aloe vera wax (Aloe vera gel was diluted with 1:3 ratio with distilled water) along with sulfur dioxide (1%) fumigation. In experiment No.5 (third phase), the combined effect of hot water, 1-MCP, CaCl2, salicylic acid and aloe vera wax was evaluated. Samples were analyzed for physicochemical, microbial and organoleptic propertiesat10 days intervals for50 days in cold storage. Hot water treatment along with 1-MCP, CaCl2, and aloe vera wax maintained physicochemical qualities, decreased the chilling injury and microbial loads and increased sensory acceptance up to 50 days followed by hot water treatment along with 1-MCP, salicylic acid, and aloe vera wax during cold storage. In experiment No.6, hot water, 1-MCP, CaCl2, salicylic acid, aloe vera wax and sulfur dioxide fumigation was used in combinations. Fruit samples were analyzed for physicochemical, microbial and sensory evaluation at 10 days intervals for 50 days in cold storage. The combined effect of the best selected treatments (hot water, 1-MCP (500 μg L -1 ),CaCl2(3%), aloe vera wax (Aloe vera gel was diluted with 1:3 ratio with distilled water) and sulfur dioxide fumigation (1%) resulted in lower microbial loads and chilling injury and higher sensory qualities during the cold storage followed by hot water, 1-MCP, salicylic acid, aloe vera wax and sulfur dioxide fumigation. The current research study provides a background for the efficient postharvest applications of hot water, 1-MCP, CaCl2, salicylic acid along with aloe vera wax and sulfur dioxide fumigation in order to reduce post harvest losses, chilling injury, microbial loads, maintain the overall quality of peaches and increase its availability in the distant markets.