RESULTSThe present research work entitled “Standardization ofpre and postharvest treatments to increase shelf life and postharvest qualityin pomegranate (Punica granatum L.)”was carried out in the Department Postharvest Technology, College of Horticulture,Bengaluru during the period 2015 to 2017. The effects of different pre andpost-harvest treatments on various physical, physiological and biochemicalparameters have been studied and explained here as follows:4.1 Effect ofpre-harvest treatments on postharvest quality of pomegranate4.
1.1. Total SolubleSolids (TSS)The results of this study have indicated that theuntreated pomegranate fruits presented a rapid increase significantly in the TSSfrom the beginning of the storage period at ambient conditions as compared tothe treated fruits (Table 4.1.1). During storage the maximum TSS was recordedat the end of the storage in S5(16.59°B) and the lowest was observedon first day of storage S1(15.12°B).
Irrespective of treatmentshighest TSS was recorded in untreated fruits T12(16.43°B) which was on par withT1(16.29°B)and whereas the lowest TSS was recorded in T11(15.35°B) which was followed byT5 and T9. The untreated (control) fruits attained maximum TSS value (16.2 °B)on 16th day of storage (Table 4.
1.1). Also, the interaction between the treatment andstorage period was also significant as the maximum TSS (17.22 °B) was observedon the 16th day of storage in T12S5 which was on par with T1S5(17.03°B)and T7S5(16.
83°B)and lowest (14.29 °B) was recorded in T11S1 which was followed by T5S1(14.52°) andT3S1(14.96°B)on the day of harvest (Table 4.
1.1). 4.1.2. pHThe data on pH presented in Table 4.1.
2 and Figure ___indicates that there was significant change in pH of the pomegranate arils andit was found declined during storage period. In different storage intervals pHwas found highest in S2(4.51) and S1(4.50) on 8th and 1stday of storage as compared to other storage intervals and whereas lowest pH wasrecorded in S4 (4.30) and S5(4.30) on 12 and 16 days after storageof fruits. Irrespective of treatments pH of the arils gradually showeddecreasing trend from the day of harvest to end of of storage.
The fruits treatedwith calcium chloride(T2) was recorded highest (4.37) pH and was on par withT8, T1, T10, T7, T6 and T9 while the lowest pH was recorded in T12(4.29) whichwas on par with T11 (4.29). The interaction between treatments and storage on pHof pomegranate fruits was found significant. in fruits in T7S1 (4.74) was recordedsignificantly highest pH and it was on par with T2S1as compared to all othertreatments. However, the lowest pH wasrecorded in T12S3 (4.
10) fruits which were at a par with T11S5(4.12). 4.
1.3. Titratable Acidity (TA %)Both the treated as well as untreated pomegranatefruits have registered a continual significantly increase in the TA duringstorage at ambient conditions (Table 4.1.
3). However, the treated fruits haveshown a significant slow increase over the untreated (control) pomegranatefruits. In different storage intervals, the highest (0.67%) was recorded in S5which was followed by S4 and lowest TA (0.48 %) was observed in S1 duringstorage of pomegranate and Whereas, among different treatments highest TA wasrecorded in T1 (0.65 %) which was followed by T10 (0.
51%) and lowest TA wasrecorded in T5 (0.48%) irrespective of the storage period. The interaction,treatment x storage period (T x S) was also significant as the highest TA (0.78%) was observed in pomegranate fruits treated with Salicylic acid (2 mM) on the12th day after harvest, and the lowest TA (0.28 %) was observed infruits received GA3(100 ppm) with BA(75ppm) (T5S1) on the day of harvest whichwas on par with T4S1 (Table 4.
1.4. AscorbicAcid Content (AAC mg 100g-1)It has been observed that the AAC of ‘Bhagwa’pomegranate fruits had significantly decreased progressively with increase instorage period (Table 4.1.4). In different storage intervals significantlyhighest AAC was recorded in S1 which was followed by S2, whereas among all the differenttreatments: T1 (11.79) recorded highest AAC which was followed by T7, T5, T6,T3, T2 and T4 and lowest was observed in T12(10.59).
At the end of storage life,the interaction between treatment x storage period (T x S) was also significantas the highest AAC (13.80, 13.80 and 13.80) was observed in T4S1, T1S1 and T9S1respectively whereas the lowest AAC was observed in T11S5 (7.80) which was onpar with T12S5 and T9S5 (Table 4.
Total Antioxidant Activity (µmolAAE g-1 FW)All the treatments have maintained higher totalantioxidant capacity in the ‘Bhagwa’ pomegranate fruits than in untreatedfruits during storage at ambient conditions (Table 4.1.5). Irrespective of thestorage period, the total antioxidant capacity was maximum (160.
85 µmol AAE g-1FW) in the fruits on the day of harvest and the lowest was recorded in S5(110.63 µmol AAE g-1 FW) at the end of the storage (Table 4.1.5).
Similarly, among treatments it differed significantly with highest (147.28 µmolAAE g-1 FW) antioxidants in T11 which was on par with T5 and T9 and thelowest antioxidant capacity (126.50 µmol AAE g-1 FW) was observed inuntreated fruits. There was a significant interaction between the treatment andstorage period and the highest antioxidant capacity (168.76 µmol AAE g-1FW) was exhibited by fruits treatments T11S1 on the day of harvest which was onpar with T9S1 and T3S1 and lowest (100.19 µmol AAE g-1 FW) wasobserved in untreated fruits, which was significantly followed by T1S5 (Table4.1.5).