3. EVALUATION OF THE EFFECTS OF THE SUPPLY CHAIN ROUTES AND PRE-
3.3 RESULTS AND DISCUSSION
3.3.3 Subjective quality analysis for marketability
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processes (such as respiration, ethylene production and transpiration) thus enhance fruit quality deterioration. Temperature affects all the metabolic processes leading to fruit quality deterioration (Aung and Chang, 2014, Workneh and Osthoff, 2015). Therefore, low storage temperatures (< 12 °C) are suitable for tomato storage in order to slow down the fruit metabolic activities, maintain fruit quality and extend the shelf-life (Pinheiro et al., 2013b).
Integration of postharvest treatments (disinfectants/ coating and storage), had highly significant difference (P < 0.001) in the marketability percentage of pink matured tomatoes stored for 30 days (Table 3.4 and 3.5). Integration of pre-storage treatments and storage conditions had significant difference (P < 0.001) in sustaining marketability of tomatoes during day 16 and 30 of both harvesting seasons. Tomatoes which were disinfected and stored at cold room retained Integration of supply routes with higher marketability than the ones stored at ambient. Similar results were reported by (Cengiz and Certel, 2014) whereby disinfection treatments followed by cold storage further extended the shelf life of different tomato varieties. Pre-storage treatments had significant difference (P < 0.001) in sustaining marketability of tomatoes during day 16 and 30 of both harvesting seasons. Integration of supply routes with storage environment also sustained tomato marketability, significantly during day 16 and 30 of both harvest seasons. Getinet et al. (2011); Wu (2010); Nunes and Emond, 1999) reported that integration of practices such as harvesting at appropriate maturity stages and ideal storage environment can possibly extend the shelf life of tomatoes by reducing the rate of ripening.
Furthermore, integration of supply routes, pre-storage treatments and storage environment had highly significant impact (P < 0.001) in sustaining marketability of tomatoes during day 16 and 30 of both harvest seasons. Fruit harvested in winter from Letaba Municipality, treated with anolyte water, and stored at 11 °C were the best during all the sampling dates with the highest marketability percentage of 44% and 42.5% during day 30 of winter and summer harvests, respectively. This also symbolise the superiority of the combined effects of different postharvest treatments. Similar results were reported by (Seyoum et al., 2011), whereby disinfecting carrots with anolyte water followed by cold storage had significant impact in extending shelf life. Therefore similar features of treatment combination make effective in extending shelf life of tomatoes.
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Table 3.4 The effect of supply chain routes, pre-storage treatments and storage temperatures on marketability of pink-matured tomatoes harvested in winter and stored for 30 days.
Treatment combination Marketability (%)
Day 0 Day 16 Day 30
Pontdrift, Control, Ambient 100a 40.0 n 1.0 o
Letaba, Control, Ambient 100a 49.0 l 2.5 mno
Esmè4, Control, Ambient 100a 32.5 p 2.5 mno
Pontdrift, Gum Arabic, Ambient 100a 40.0 n 2.5 mno
Letaba, Gum Arabic, Ambient 100a 60.0 i 4.5 kl
Esmè4, Gum Arabic, Ambient 100a 30.0 q 5.0 k
Pontdrift, Hot Water, Ambient 100a 42.5 m 5.0 k
Letaba, Hot Water, Ambient 100a 54.0 k 3.3 lm
Esmè4, Hot Water, Ambient 100a 50.0 l 5.0 k
Pontdrift, Chlorine, Ambient 100a 60.0 i 5.0 k
Letaba, Chlorine, Ambient 100a 58.3 j 6.0 k
Esmè4, Chlorine, Ambient 100a 35.0 o 3.7 lm
Pontdrift, Anolyte, Ambient 100a 42.5 m 7.5 j
Letaba, Anolyte, Ambient 100a 62.5 h 7.5 j
Esmè4, Anolyte, Ambient 100a 55.0 k 5.8 k
Pontdrift, Control, Cold 100a 90.0 d 20.0 f
Letaba, Control, Cold 100a 82.5 e 20.0 f
Esmè4, Control, Cold 100a 62.5 h 7.5 j
Pontdrift, Gum Arabic, Cold 100a 100 a 10.0 i
Letaba, Gum Arabic, Cold 100a 97.5 b 20.0 f
Esmè4, Gum Arabic, Cold 100a 97.5 b 17.5 g
Pontdrift, Hot Water, Cold 100a 72.5 g 37.5 b
Letaba, Hot Water, Cold 100a 100 a 22.2 e
Esmè4, Hot Water, Cold 100a 75.0 f 12.5 h
Pontdrift, Chlorine, Cold 100a 75.0 f 30.5 c
Letaba, Chlorine, Cold 100a 90.0 d 32.5 c
Esmè4, Chlorine, Cold 100a 92.5 c 22.5 e
Pontdrift, Anolyte, Cold 100a 100 a 32.5 c
Letaba, Anolyte, Cold 100a 100 a 44.0 a
Esmè4, Anolyte, Cold 100a 97.5 b 22.5 e
Route (A) NS <0.001 <0.001
Treatment (B) NS <0.001 <0.001
Storage (C) NS <0.001 <0.001
A×B NS <0.001 <0.001
A×C NS <0.001 <0.001
B×C NS <0.001 <0.001
A×B×C NS <0.001 <0.001
Means followed by the same letter(s) are not significant: Duncan’s multiple range test (P < 0.05) The LSD value = 1.36, C.V = 6.1, S.E = 0.8333
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Table 3.5 The effect of supply chain routes, pre-storage treatments and storage temperatures on marketability of pink-matured tomatoes harvested in summer and stored for 30 days.
Treatment combination Marketability (%)
Day 0 Day 16 Day 30
Pontdrift, Control, Ambient 100a 49.0 p 2.5 n
Letaba, Control, Ambient 100a 52.5 o 3.3 mn
Esmè4, Control, Ambient 100a 60.0 lmn 1.0 o
Pontdrift, Gum Arabic, Ambient 100a 60.0 lmn 4.5 lm
Letaba, Gum Arabic, Ambient 100a 61.0 m 10.5 i
Esmè4, Gum Arabic, Ambient 100a 40.0 r 2.5 n
Pontdrift, Hot Water, Ambient 100a 54.0 o 0.0 o
Letaba, Hot Water, Ambient 100a 50.0 p 8.50 j
Esmè4, Hot Water, Ambient 100a 42.5 q 5.0 l
Pontdrift, Chlorine, Ambient 100a 58.0 n 7.0 k
Letaba, Chlorine, Ambient 100a 65.0 k 12.3 h
Esmè4, Chlorine, Ambient 100a 60.0 mn 5.0 l
Pontdrift, Anolyte, Ambient 100a 62.5 l 7.5 kj
Letaba, Anolyte, Ambient 100a 65.0 k 13.5 h
Esmè4, Anolyte, Ambient 100a 42.5 q 2.5 n
Pontdrift, Control, Cold 100a 82.5 h 20.0 f
Letaba, Control, Cold 100a 92.5 e 20.0 f
Esmè4, Control, Cold 100a 86.7 g 7.5 jk
Pontdrift, Gum Arabic, Cold 100a 97.5 abcd 10.0 i
Letaba, Gum Arabic, Cold 100a 100 a 20.0 f
Esmè4, Gum Arabic, Cold 100a 97.5 abd 17.5 g
Pontdrift, Hot Water, Cold 100a 100 a 37.5 c
Letaba, Hot Water, Cold 100a 75.0 i 22.5 e
Esmè4, Hot Water, Cold 100a 72.5 j 12.5 h
Pontdrift, Chlorine, Cold 100a 89.7 f 42.5 a
Letaba, Chlorine, Cold 100a 92.5 e 32.5 d
Esmè4, Chlorine, Cold 100a 75.0 i 22.5 e
Pontdrift, Anolyte, Cold 100a 100 a 22.5 e
Letaba, Anolyte, Cold 100a 100 a 42.5 a
Esmè4, Anolyte, Cold 100a 97.5 ad 22.5 e
Route (A) NS <0.001 <0.001
Treatment (B) NS <0.001 <0.001
Storage (C) NS <0.001 <0.001
A×B NS <0.001 <0.001
A×C NS <0.001 <0.001
B×C NS <0.001 <0.001
A×B×C NS <0.001 <0.001
Means followed by the same letter(s) are not significant: Duncan’s multiple range test (P < 0.05) The LSD value = 1.28, C.V = 5.2, S.E = 0.7853
The results generally revealed an expected, negative (inverse), relationship between the total microbial burden and fruit marketability. The increase in microbial burden resulted in fruit
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marketability being significantly (P < 0.001) reduced. These results are in line with the ones reported by (Teka, 2013) who stated that microbial load in tomatoes are major determinant of fruit quality and consumer’s safety after consuming fruit. The higher the microbial load on the fruit surface, the higher the chances of fruit being infected by microbial contamination (Teka, 2013). Generally, marketability % was higher during winter harvest, than summer, and there was highly significant difference (P < 0.001) between the marketability % of fruit harvested in winter and in summer (Figures 3.1a and 3.1b). Fruit treated with anolyte water reflected a better condition compared to fruit treated with other treatments. They were shiny, firmer, with no surface blemishes (Table 3.6). Chlorine treated fruit were also looking good, however they possessed some surface defects. Gum Arabic treated fruit were also attractive, but less attractive than the ones treated by anolyte water. Hot water treated tomatoes possessed surface burns thus less attractive. Control (untreated) fruit were also unattractive, mainly due to shrinkage and being dull and also exhibited surface blemishes.
Figure 3.1 The effect of supply chain routes and harvesting seasons in the marketability of tomatoes under ambient and cold storage conditions during day 16.
0 20 40 60 80 100
Pontdrift Letaba Esme4
Marketability (%)
Supply chain routes Winter
Ambient LSD = 0.551 Cold
P < 0.001
0 20 40 60 80 100
Pontdrift Letaba Esme4
Marketability (%)
Supply chain routes Summer
Ambient LSD = 0.574 Cold
P < 0.001
(a) (b)
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Table 3.6 The effect of pre-storage treatments and storage temperatures on an overall perce- ntage marketability of pink-matured tomatoes harvested in summer and stored for 30 days
Treatments Storage Final state of marketability during day 30 Rating Anolyte water Ambient Red shiny, firm, no blemishes Good
Cold Red shiny, firm, no blemishes Excellent
Chlorine Ambient Red shiny, firm, surface blemishes Good Cold Red shiny, firm, surface blemishes Good
Gum Arabic Ambient Red shiny, firm, no blemishes Good
Cold Red shiny, firmer, no blemishes Good
HWT Ambient Orange-red shiny, soft, surface burn Poor
Cold Orange-red shiny, soft, surface burn Fair
Control Ambient Red dull, shrinkage, blemishes Poor
Cold Red dull, shrinkage, blemishes Fair
The level of marketability started from ‘Fair’, ‘Good’ and ‘Excellent’. Fruit that were rating
‘Poor’ were unmarketable.