The chemicals to remove ethylene in the bags, respectively potassium- permanganate, active coal and their combination, did not seem to affect weight
loss. The perforations do exert greater effect than these substances on weight loss.
4.2. Ambient Temperature Storage day 14-16
4.2.1. Weight Loss
Average weight loss during the 3 day room-temperature storage is presented in Table 8.
Table 8. Average Weight Loss at Day 15 and 16 at Ambient Temperature 23
o
-27
o
C Weight Loss by initial weight
on Day Treatment
15 16
A 0.56
0.85
B
0.36 0.65
C 0.51
0.89
D 0.21
0.86
E 0.45
0.99
F 0.49
1.06
G
0.43 0.78
H 0.60
0.71
Average of 2 replicates
Average weight loss on day 15 and 16 were higher in the perforated poly- bags than in the un-perforated ones. This is possibly due to the free movement of
air from the packages into the environment, resulting greater evaporation of moisture from the commodity.
The ethylene removing chemicals within the poly-bags, however, did not show consistent effects on average weight loss.
4.2.2. Curd Surface Color
Curd surface color changes during the 3 day storage at ambient temperature 23
-27 C is presented in Table 9.
Table. 9 Curds Surface Color Changes during Ambient Storage 23
o
-27
o
C
Treat- ment
Day 14 Day 15
Day 16 A
L = 65.82 - 66.53
a = -7.5 - -8.05
b = 8.74 - 10.22
L = 55.03 - 61.58
a = -7.16 - -9.68
b = 9.36 - 14.35
L = 60.15 - 62.33
a = -6.2 - -7.6
b = 12.25 - 13.80
B
L = 54.90 - 61.31
a = -7.85 - -10.22
b = 11.25 - 13.54
L = 60.27 - 62.52
a = -6.41 - -7.33
b = 12.71 - 13.46
L = 58.84 - 63.96
a = - 10.32 - -12.87
b = 13.78 - 18.55
C
L = 55.04 - 61.16
a = -7.14 - -10.26
b = 9.35 - 13.47
L = 60.81 - 68.01
a = -7.8 - -9.51
b = 10.84 - 13.41
L = 62.52 - 65.58
a = - 6.41 - -10.42
b = 12.71 - 19.84
D
L = 64 - 59.02
a = -7.65 - -9.42
b = 10.77 - 13.89
L = 64.64 - 68.4
a = -7.71 - -9.27
b = 10.37 - 14.23
L = 62.04 - 62.89
a = -6.41 - -10.42
b = 12.71 - 19.84
E
L = 59.05 - 61.01
a = -7.31 - -8.45
b = 10.01 - 11.56
L = 67.18 - 69.76
a = -9.13 - -9.63
b = 11.62 - 11.70
L = 62.44 - 66.94
a = - 10.75 - -11.45
b = 20.09 - 22.41
F
L = 59.02 - 59.06
a = -7.65 - -9.42
b = 10.77 - 13.89
L = 65.27 - 68.4
a = -8.84 - -9.88
b = 10.25 - 12.28
L = 61.56 - 64.70
a = - 11.38 - -12.50
b = 19.3 - 21.52
G
L = 59.65 - 61.25
a = -7.31 - -8.45
b = 10.01 - 11.56
L = 62.50 - 64.69
a = -7.46 - -8.29
b = 9.49 - 10.65
L = 62.93 - 64.09
a = -9.7 - -10.85
b = 18.88 - 23.17
H
L = 61.05 - 64.74 a = -7.56 - -10.15
b = 9.35 - 10.46 L = 55.89 - 60.60
a = -7.5 - -9.83 b = 10.51 - 14.24
L = 64.57 - 65.78 a = -12.75 - -12.88
b = 20.65 - 23.13
Curd surface color on day 15 in the un-perforated bags as well as the perforated ones did not change much when compared to day 14. However on day
16 both showed significant yellowing. Yellowing of curds were more severe in the perforated poly-bags A to H than in the un-perforated ones A-D.
Replicate 1
Less severe yellowing in the un-perforated bags might be related to the modified atmosphere packaging. Salunkhe and Desai 1984 reported that
modified atmospheres containing 10, 5, 2.5 or 1 oxygen flushed over broccoli at 23.9
C for 3 days, significantly reduced respiration rate and completely stopped yellowing of the curd. In this experiment yellowing still
occurred, but was less intense. No different effect on yellowing could be detected among the different ethylene removing substances used.
The more severe yellowing in the perforated bags could be caused by the room temperature of 23
-27 C. Ambient temperature increased both rate of
respiration and other metabolic processes, including ethylene synthesis. These resulted in rapid loss of chlorophyll and the green color of the curd Reid, 1992.
Moreover, normal O
2
and CO
2
concentrations within the perforated package promote ethylene production Reid, 1992, while normal CO
2
concentration accelerated ethylene induced chlorophyll degradation and thus yellowing of the
curd Barth et al., 1993.
4.2.3. Incidence of Soft rot
