INTRODUCTION Ber (Zizyphus mauritiana Lamk.) is a hardy fruit crop and its fruits are a good source of Vitamin C and minerals like calcium, phosphorus and iron. It is an ideal fruit for cultivation in the arid and semi-arid zones of northern India, because of its very low irrigation requirement in the hot and dry months of May and June, when it sheds its leaves and enters into a period of dormancy. Due to high economic returns, improved budded varieties of ber are being cultivated on a commercial scale in Punjab, Haryana, Rajasthan and Uttar Pradesh. Ber can thrive well under adverse conditions, viz., salinity, drought and water- logging. However, high post-harvest losses are a major constraint in developing the ber fruit industry in the country. Ber fruits are perishable in nature and cannot be stored for long periods under ambient conditions (Salunkhe and Kadam, 1995). Calcium compounds are known to extend the shelf-life of several fruits by maintaining firmness, minimizing the rate of respiration, protein breakdown and disease incidence (Gupta et al, 1980). Growth regulators also increase the post harvest life of fruits by retarding of ripening, senescence, by minimizing the rate of respiration and by reduction in weight loss (Huang, 1974). The ber industry can take a further leap if its post-harvest life is Effect of post-harvest treatment on storage quality in ‘Umran’ ber fruit S. K. Jawandha, J. S. Randhawa, P. P. S. Gill and Jagjit Singh Department of Horticulture Punjab Agricultural University, Ludhiana – 141 004, India E- mail: punjabbeauty2000@rediffmail.com ABSTRACT An experiment was conducted to study the effect of post-harvest sprays of CaCl 2 (@ 0.5%, 1.0% & 2.0%), Ca(NO 3 ) 2 (@ 0.5%, 1.0% & 2.0%), GA 3 (@ 20, 40 and 60 ppm) and Bavistin (0.1%) on storage quality of ‘Umran’ ber’. Fruits of uniform size were harvested at physiological maturity and treated with various chemicals. Treated fruits were placed in CFB boxes and placed in cold storage (3-5 °C and 85-95% RH). Stored fruits were evaluated at 10, 20 and 30 days from storage for palatability rating, TSS, acidity, Vitamin C and total sugars. After 30 days from storage, the highest palatability rating was recorded in GA 3 (60 ppm) treated fruits, followed by CaCl 2 (2.0%). Both TSS and Total sugars showed a similar trend of increase upto 20 days from storage, followed by a decrease. However, acidity and Vitamin C content of fruits decreased continuously with advancement of storage period. At the end of storage, maximum TSS, total acidity Vitamin C and total sugars were observed in GA 3 (60 ppm) treated fruits, followed by CaCl 2 (2.0%). Studies revealed that GA 3 (60 ppm) treated ber fruits maintained very good quality at 20 days of cold storage. Key words: Ber, GA 3 , calcium, post-harvest treatment, cold storage extended without significant deterioration in fruit quality. The present study was, therefore, undertaken to study the effect of post-harvest treatments with various chemical compounds on the quality of ber fruit during cold storage. MATERIAL AND METHODS The present study was conducted in the Department of Horticulture, Punjab Agricultural University, Ludhiana during the years 2002 and 2003. Uniform sized fruits of ‘Umran’ cultivar were harvested at optimum maturity from the marked trees. The fruits were dipped in aqueous solution (at 20°C) of different compounds, viz., as CaCl 2 (0.5, 1.0 & 2.0%), Ca(NO 3 ) 2 (0.5, 1.0 & 2.0 %), GA 3 (20, 40 & 60 ppm) and Bavistin (0.1%) for five minutes. Treated fruits were then air dried in shade, packed in Netlon bags (1.0 kg) and placed in CFB boxes (30.0 x 21.5 x 21.5 cm) of 5% perforation with paper lining. Thereafter, these boxes were kept in cold storage (3-5°C and 85-95% RH). The experiment was laid out in completely randomized block design with eleven treatments and three replications. Each replication comprised of one kilogram fruit. Fruit samples were analysed for physico-chemical changes like palatability rating (PR), TSS, acidity, Vitamin C content and total sugars at 10, 20 and 30 days of storage. Palatability J. Hortl. Sci. Vol. 3 (1): 48-52, 2008 page 48 49 rating (PR) was recorded on the basis of a score card viz., 1-poor; 2-Fair; 3-Good; 4-Very good and 5-Excellent (Dhanrai et al, 1980). Total soluble solids (TSS) were determined with the help of hand refractometer from the juice of fruit and the values were corrected at 20°C. Fruit acidity was estimated by titrating the juice against standard 0.1 N sodium hydroxide solution using phenolphthalein as indicator and represented as per cent. Vitamin C content was determined by titrating the juice against 2, 6- dichlorphenol indophenol dye solution to a light pink colour, which persisted for 15 seconds. Results were expressed as mg/100 g of fruit flesh. Total sugars were estimated by titrating boiling Fehling Solution (5 ml A + 5 ml B) against aliquot using methylene blue as the indicator (A.O.A.C., 1980). RESULTS AND DISCUSSION Palatability rating (PR) of fruits decreased significantly with advancement of storage period regardless of the post harvest treatment (Table 1). At the end of storage, fruits treated with GA 3 (60 ppm) showed maximum PR (3.16 & 3.25). Prolongation of fruit life due to growth regulators is probably due to effectiveness of these chemicals in retardation of ripening and senescence and reduction in weight loss (Huang, 1974). Likewise, various calcium treatments significantly increased PR as compared to control. Increase in calcium content of the fruits has been associated with reduced softening (Haggag, 1987), decreased incidence of physiological disorders and improved storage life (Raese, 1986). Similar results were also reported by Chahal and Bal (2003) in ber fruits. TSS content of fruits increased upto 20 days of storage in all the treatments, except the control, which recorded increase in TSS content only upto 10 days of storage (Table 2). But, at 30 days of storage, decrease in TSS content was noticed in all the treatments. Jawanda et al (1980) also reported inconsistent trend in TSS of ber fruits during cold storage. Among the different treatments, GA3 (60 ppm) recorded the maximum TSS at the end of storage, closely followed by CaCl 2 (2.0%) treatment. This might be due to reduction in metabolic activities like respiration and senescence by GA 3 (60 ppm) and CaCl 2 (2.0%) treatments. During the course of investigation, there was an initial rise in TSS content of fruits till it reached the peak, followed by a gradual decline after 30 days of storage. The initial increase in TSS may be due to hydrolysis of starch into mono-and di-saccharides, and, on complete hydrolysis of starch, no further increase occurred. Subsequently, a decline was observed because of utilization of the primary substrate for respiration (Wills et al, 1980). Fruit acidity showed a general decline in all the treatments as storage period progressed (Table 3). Such a decrease in acidity might be attributed to conversion of acids to sugars and then utilization in the respiration process (Pool et al, 1972). Sandbhor and Desai (1991) also reported a gradual decrease of acid content in ber fruit during storage. After 30 days of cold storage, lowest acidity was recorded Table 1. Effect of post-harvest treatment on palatability rating in ber fruits during cold storage Palatability rating Treatment 2002 2003 Days after storage Days after storage 10 20 30 Mean 10 20 30 Mean CaCl- 2 0.5% 4.58 3.25 2.30 3.38 4.40 3.15 2.40 3.32 CaCl- 2 1.0% 4.66 3.30 2.40 3.45 4.50 3.41 2.50 3.47 CaCl- 2 2.0% 4.80 3.70 3.00 3.83 4.80 3.60 3.10 3.83 Ca(NO 3 ) 2 0.5% 4.41 3.00 2.15 3.19 4.30 3.00 2.20 3.17 Ca(NO 3 ) 2 1.0% 4.60 3.15 2.20 3.31 4.38 3.00 2.33 3.24 Ca(NO 3 ) 2 2.0% 4.50 3.40 2.50 3.46 4.58 3.50 2.75 3.61 GA 3 20 ppm 4.60 3.20 2.30 3.37 4.50 3.33 2.50 3.44 GA 3 40 ppm 4.75 3.50 2.75 3.67 4.70 3.60 2.85 3.72 GA 3 60 ppm 4.80 4.00 3.16 3.97 4.83 3.75 3.25 3.94 Bavistin 0.1% 4.00 3.00 2.00 3.00 4.25 3.10 2.00 3.12 Control (untreated) 3.75 2.50 1.60 2.62 3.83 2.60 1.62 2.68 Mean 4.50 3.27 2.40 4.46 3.28 2.50 CD (P=0.05) Treatments (A) = 0.213 0.183 Storage days (B) = 0.111 0.196 Interaction (A x B) = 0.302 0.210 Post-harvest storage quality in ber J. Hortl. Sci. Vol. 3 (1): 48-52, 2008 50 in untreated fruits, whereas highest acidity was observed with GA 3 (60 ppm) followed by CaCl 2 (2.0%) treatment. This might be due to low respiration rate in GA 3 (60 ppm) and CaCl 2 (2.0%) treatments. Data pertaining to Vitamin C content in the fruit are presented in Table 4. Significant decrease in Vitamin C content was noted with advancement of storage period in all the treatments. These findings were in accordance with the results of Bal et al (1978) who reported a decrease in Vitamin C content with prolongation of storage period. Reduction in Vitamin C content might be attributed to its oxidation in the presence of molecular oxygen by ascorbic acid oxidase (Mapson, 1970; Tarkase and Desai, 1989). At the end of storage, minimum Vitamin C content was found in Control fruits, whereas, it was maximum in GA 3 (60 ppm) treated fruits, followed by CaCl 2 (2.0%) treatment, which may be a result of low respiration transpiration rates and delayed senescence (Huang,1974; Faust and Shear, 1972). Total sugars showed an increasing trend up to 20 days of storage in all the treatments except in control, but decreased after 30 days of storage. Similar results were also reported by Jayachandran et al (2005) in gauva fruits. Stahl and Camp (1971) reported certain cell wall materials such Table 2. Effect of post-harvest treatment on total soluble solids in ber fruits during cold storage TSS% Treatment 2002 2003 Days after storage Days after storage 10 20 30 Mean 10 20 30 Mean CaCl- 2 0.5% 13.66 14.40 12.50 13.52 13.53 14.30 12.60 13.48 CaCl- 2 1.0% 13.53 14.20 12.66 13.46 13.40 14.20 12.70 13.43 CaCl- 2 2.0% 13.46 13.80 12.86 13.37 13.35 13.80 12.94 13.36 Ca(NO 3 ) 2 0.5% 13.80 14.80 12.30 13.63 13.60 14.40 12.46 13.49 Ca(NO 3 ) 2 1.0% 13.70 14.40 12.45 13.52 13.60 14.20 12.60 13.46 Ca(NO 3 ) 2 2.0% 13.60 14.00 12.70 13.43 13.50 14.00 12.80 13.43 GA 3 20 ppm 13.60 14.40 12.60 13.53 13.60 14.20 12.70 13.50 GA 3 40 ppm 13.40 13.93 12.80 13.38 13.42 13.80 12.85 13.36 GA 3 60 ppm 13.40 13.70 13.00 13.37 13.20 13.73 13.13 13.35 Bavistin 0.1% 13.66 14.60 12.33 13.53 13.70 14.40 12.40 13.50 Control (untreated) 14.80 13.80 12.10 13.57 14.80 13.86 12.00 13.55 Mean 13.69 14.18 12.57 13.61 14.08 12.65 CD (P=0.05) Base value = 13.20 Base value = 13.10 Treatments (A) = 0.072 0.008 Storage days (B) = 0.088 0.010 Interaction (A x B) = 0.029 0.033 Table 3. Effect of post-harvest treatment on acidity in ber fruits during cold storage Treatment Acidity (%) 2002 2003 Days after storage Days after storage 10 20 30 Mean 10 20 30 Mean CaCl- 2 0.5% 0.154 0.144 0.128 0.142 0.157 0.143 0.132 0.144 CaCl- 2 1.0% 0.157 0.144 0.130 0.143 0.160 0.150 0.137 0.149 CaCl- 2 2.0% 0.164 0.152 0.140 0.152 0.170 0.156 0.142 0.156 Ca(NO 3 ) 2 0.5% 0.152 0.139 0.122 0.137 0.155 0.140 0.130 0.142 Ca(NO 3 ) 2 1.0% 0.157 0.140 0.126 0.141 0.160 0.150 0.134 0.148 Ca(NO 3 ) 2 2.0% 0.164 0.146 0.134 0.148 0.164 0.148 0.138 0.150 GA 3 20 ppm 0.160 0.148 0.136 0.148 0.164 0.152 0.138 0.151 GA 3 40 ppm 0.167 0.150 0.138 0.151 0.174 0.152 0.140 0.155 GA 3 60 ppm 0.170 0.156 0.142 0.156 0.174 0.159 0.148 0.160 Bavistin 0.1% 0.152 0.140 0.124 0.138 0.157 0.146 0.132 0.145 Control (untreated) 0.140 0.132 0.120 0.130 0.150 0.138 0.118 0.135 Mean 0.157 0.144 0.131 0.162 0.148 0.135 CD (P=0.05) Base value = 0.173 Base = 0.176 Treatments (A) = 0.0034 0.0032 Storage days (B) = 0.0018 0.0017 Interaction (A x B) = NS NS Jawandha et al J. Hortl. Sci. Vol. 3 (1): 48-52, 2008 51 as pectin and hemicellulose to be converted into reducing substances during prolonged storage. At the end of the storage, maximum total sugars content were recorded in GA 3 (60 ppm) and CaCl 2 (2.0%) treated fruits, whereas untreated fruits registered minimum total sugars content (Table 5). It might be due to low respiration rate and delayed senescence in GA 3 and CaCl 2 (2.0%) treated fruits. Gupta et al (1984) stated that calcium compounds significantly thickened middle lamella of the fruit cells owing to increased deposition of calcium pectate, thereby maintaining the cell wall and cell wall material. Table 4. Effect of post-harvest treatment on Vitamin C content in ber fruits during cold storage Treatment Vitamin C (mg/100 g fruit flesh) 2002 2003 Days after storage Mean Days after storage Mean 10 20 30 10 20 30 CaCl- 2 0.5% 82.76 62.80 53.68 66.41 83.25 63.45 55.03 67.24 CaCl- 2 1.0% 84.32 67.08 57.63 69.67 87.20 67.12 57.83 70.72 CaCl- 2 2.0% 90.87 71.42 60.88 74.39 92.86 71.79 63.92 76.19 Ca(NO 3 ) 2 0.5% 82.80 60.40 52.29 65.16 82.40 60.93 54.49 65.94 Ca(NO 3 ) 2 1.0% 85.98 63.84 55.62 68.48 84.80 66.41 56.34 69.18 Ca(NO 3 ) 2 2.0% 86.72 65.27 58.26 70.08 88.32 67.44 59.74 71.83 GA 3 20 ppm 88.44 67.35 56.82 70.87 90.40 68.36 57.62 72.13 GA 3 40 ppm 91.59 70.23 59.83 73.88 93.82 72.62 62.03 76.16 GA 3 60 ppm 95.10 73.48 62.39 76.99 96.56 79.46 64.48 80.16 Bavistin 0.1% 80.82 61.13 55.10 65.68 82.34 62.10 52.80 65.75 Control (untreated) 77.73 56.02 50.69 61.48 79.20 57.26 49.87 62.11 Mean 86.10 65.36 56.65 87.38 66.99 57.65 CD (P=0.05) Base value = 96.79 Base value = 98.93 Treatments (A) = 1.224 1.018 Storage days (B) = 0.639 0.532 Interaction (A x B) = 2.121 1.764 Table 5. Effect of post-harvest treatment on total sugars in ber fruits during cold storage Treatment Total sugars (%) 2002 2003 Days after storage Mean Days after storage Mean 10 20 30 10 20 30 CaCl- 2 0.5% 10.08 10.38 9.00 9.82 10.01 10.30 9.02 9.78 CaCl- 2 1.0% 9.92 10.27 9.02 9.74 9.89 10.26 9.10 9.75 CaCl- 2 2.0% 9.84 10.00 9.22 9.69 9.70 10.07 9.29 9.68 Ca(NO 3 ) 2 0.5% 10.16 10.67 8.80 9.87 10.10 10.35 8.93 9.79 Ca(NO 3 ) 2 1.0% 10.10 10.37 8.92 9.80 10.10 10.26 9.02 9.79 Ca(NO 3 ) 2 2.0% 9.90 10.17 9.09 9.72 9.90 10.17 9.16 9.74 GA 3 20 ppm 9.90 10.38 9.02 9.76 9.92 10.28 9.10 9.76 GA 3 40 ppm 9.82 10.10 9.18 9.70 9.77 10.10 9.20 9.69 GA 3 60 ppm 9.78 9.90 9.30 9.66 9.68 9.92 9.40 9.66 Bavistin 0.1% 10.10 10.65 8.82 9.86 10.14 10.37 8.90 9.80 Control (untreated) 10.69 10.15 8.73 9.86 10.60 9.90 8.84 9.78 Mean 10.02 10.27 9.01 9.98 10.18 9.08 CD (P=0.05) Base value= 9.71 Base value = 9.60 Treatments (A) = 0.061 0.059 Storage days (B) = 0.092 0.072 Interaction (A x B) = 0.030 0.040 REFERENCES A.O.A.C. 1980. Official methods of analysis of analytical chemists. Association of the Official Analytical Chemists, Washington, D.C. Bal, J. S. Singh, P. and Singh, R. 1978. Preliminary observations on the storage behaviour of ber at room and refrigerated temperature. J. Res. Punjab Agri. Univ., Ludhiana 25: 396-99. Chahal, S. and Bal, J. S. 2003. Effect of post-harvest treatments and packaging on shelf-life of ‘Umran’ ber at cool temperature. J. Res. Punjab. Agri. Univ., 40 : 363-370. Post-harvest storage quality in ber J. Hortl. Sci. Vol. 3 (1): 48-52, 2008 52 Dhanraj, S., Ananihakrishna, S. M. and Govindrajan, V. S. 1980. Apple quality: development of descriptive quality profile for objective sensory evaluation. J. Food Qual. 4 : 83-100. Faust, M. and Shear, C. B. 1972. The effect of calcium on respiration of apples. J. Amer. Soc. Hortl. Sci., 97 : 437-439. Gupta, O. P. Jindal, P. C and Singh, B. P. 1980. Effect of pre-harvest spray of calcium nitrate on the storage behaviour of grapes cv. Perlette. J. Res. Haryana Agri. Univ., 10: 204-206. Gupta, O. P. Singh, B. P. Singh, S. P. and Chauhan, K. S. 1984. Effect of calcium compounds as pre-harvest spray on the shelf life of peach cv. Sharbati. Punjab Hort. J., 24 : 105-110. Haggag, M. N. 1987. Effects of pre-harvest and post-harvest calcium treatments on storage behaviour of LeConte pears. Alexandra J. Agri. Res., 32 : 175-188. Huang, C. C. 1974. Maintaining freshness of pineapple fruits for export. Taiwan Agril. Quarterly, 10: 103-11. Jayachandran, K. S., Srihari, D. and Reddy, Y. N. 2005. Pre-harvest sprays of different sources of calcium to improve the shelf-life of guava. Ind. J. Hortl. Sci., 62: 68-70. Jawanda, J. S., Bal, J. S., Josan, J. S. and Mann, S. S. 1980. Studies on storage of ber fruit II. Cool temperature. Punjab Hort. J., 20 : 56-61. Mapson, L.W. 1970. Vitamins in fruits: Stability of L- (MS Received 3 September 2007, Revised 19 April 2008) ascorbic acid. In: Biochemistry of Fruits and their products. Vol. I (Ed., A.C. Hulme). Academic Press, London 376-377. Pool, K. M. Weaver, R. J. and Kliewer, K. M. 1972. The effect of growth regulators on changes in fruits of Thompson Seedless during cold storage. J. Amer. Soc. Hortl. Sci., 97: 67-70. Rasese, J. T. 1986. Nitrogen and calcium important in determining yield, fruit quality and disorders of ‘Anjou’ pears. In. Proc. Pac. Northwest Tree Fruit Short Course. pp. 155-168. Salunkhe, D. K. and Kadam, S. S. 1995. Handbook of Fruit Science and Technology pp 387. Marcel Dekker Inc., New York. Sandbhor, D. R. and Desai, U. T. 1991. Influence of post harvest treatment on the shelf life of ber (Zizyphus mauritiana Lamk.) cv. Umran. Mah. J. Hort., 5: 24- 28. Stahl, A. C. and Camp, A. F. 1971. Citrus fruits. In The Biochemistry of Fruits and their Products (Ed., Hulme A C). 2: 107-169. Tarkase, E. G. and Desai, U. T. 1989. Effects of packaging and chemicals on storage of orange cv. Mosambi, J. Mah. Agri. Univ., 14: 10-13. Wills, R. B. H. Babmbridge, P. A. and Scott, K. J. 1980. Use of flesh firmness and their objectives tests to determine the consumer acceptability of Delicious apple. Aust. J. Agri. Anim. Husb., 20: 252-256. J. Hortl. Sci. Vol. 3 (1): 48-52, 2008 Jawandha et al