Thirsty vines Summer girdling Compost teas Organic marketing The ...
Thirsty vines Summer girdling Compost teas Organic marketing The ... Thirsty vines Summer girdling Compost teas Organic marketing The ...
mgg -1 FW Figure 2: The kiwifruit pulp system used to study interactions between sugar, acid and fl avour compounds. Figure 3: Acid concentrations in different Actinidia species. fruit. While the total amounts of acid in species ‘one’ fruit were similar to those in GREEN and GOLD, quinic acid made up 80 per cent of the total acid, with some malic acid but very little citric acid. Low acid levels were found in both species ‘two’ and species ‘three’ fruit. Both species had very little quinic acid, and species ‘two’ also had low citric acid levels. These differences in acid levels would contribute to very different fl avour profi les. This suggests that there is potential to use between-species variation in acidity to infl uence novel fl avours for new commercial cultivars. SEASONAL CHANGES IN ACID LEVELS IN GREEN AND GOLD FRUIT We measured the individual acid composition of both GREEN and GOLD fruit over a season from fl owering, throughout fruit development until commercial harvest. The total concentration of acid in GREEN fruit increased rapidly during the fi rst 60-80 days after fl owering, coinciding with the rapid growth of fruit (Figure 4A). Total acids were also high during the early development of GOLD fruit. Thereafter levels declined slightly, reaching constant levels during fruit maturation. Quinic acid is the main acid present during the early development of both GREEN and GOLD fruit and is mostly produced in the 60 days after fl owering (Figure 4C). In contrast, citric acid (Figure 4B) only accumulates in fruit during fruit expansion, with concentrations staying stable or increasing slightly prior to fruit maturation and harvest. This suggests that quinic acid and citric acid production are not linked, but controlled separately (Cheng et al. 2004). In both GREEN and GOLD fruit, levels of malic acid vary widely before fi nally increasing prior to harvest (Figure 4D). EFFECTS OF CLIMATE AND MANAGEMENT ON FRUIT ACIDS Climate and management techniques are likely to affect fruit acidity and taste, but there have been few concerted efforts to record the effects of climate or preharvest treatment on kiwifruit acidity. Recent studies have shown that acidity levels in kiwifruit fruit are strongly correlated with fruit DM levels (Woodward and Clearwater 2007). Therefore we expect changes in both the environment and management that alter fruit DM content will also affect fruit acidity. For example, high temperatures during fruit expansion resulted in a major reduction in both fruit DM and total acid levels of GREEN fruit at harvest (Richardson et al. 2004). However in the same study, heating vines during fruit maturation reduced fruit DM, but did not affect fruit acidity. This suggests that in some cases DM and acid levels may respond differently to either management techniques or environmental factors. Therefore it may be important to measure acid levels during studies targeted at increasing DM. The combination of both growing conditions and storage conditions can also affect fruit acidity and fl avour. At harvest, acid levels of kiwifruit grown in warm conditions in California and Italy (Crisosto and Crisosto 2001; Tombesi et al. 1993) are around 2.5-3.5 per cent TA, compared with about 1.4 per cent TA in New Zealand fruit (MacRae et al.1989). However, acid levels in fruit grown in warmer climates can drop by 50 per cent during storage at 0°C, while there is little change in the acidity of New Zealand fruit during storage. In Italy, Tombesi et al. (1993) found that GREEN fruit which was artifi cially shaded had higher acidity levels at harvest than fruit grown in standard conditions, but the difference was lost in storage. In New Zealand, studies have shown that malic acid levels in fruit can increase and soluble solids levels decrease when fruit are stored at 4°C, but not at 0° or 10°C (Marsh et al. 2004). Malic acid levels can also vary in fruit stored in different CA environments (Harman and McDonald 1989). Therefore, effects on fruit acid levels may explain some of the differences in fl avour between fruit grown in different countries or stored under different conditions. SUMMARY The fl avour of fruit has a large impact on consumer acceptance. Kiwifruit fl avour is largely determined by both the amount and balance between sugars, acids and volatile NZ KIWIFRUIT JOURNAL JANUARY / FEBRUARY 2008 43
44 aroma compounds. Dry Matter is a good indicator of a fruit’s taste potential. Both sugars and acids levels increase with increasing fruit DM, however it is the balance between the two and the type of acids present (quinic, citric and malic) that gives consumers their overall impression of fruit taste. Widely varying total acid levels and the proportion of different acids present in Actinidia germplasm give some potential to create novel fl avours through varying acid:sugar ratios in new cultivars. Environmental and fruit storage conditions as well as management techniques can all affect fruit fl avour, either by changing both DM and acidity, or by more specifi c effects on acidity alone. ACKNOWLEDGEMENT This research was funded by the New Zealand Foundation for Research, Science and Technology Contract No. C06X0403. REFERENCES FW mgg -1 FW mgg -1 Cheng, C. H., A. G. Seal, et al. (2004). “Inheritance of taste characters and fruit size and number in a diploid Actinidia A B 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 25 50 75 100 125 150 175 200 50 40 30 20 10 Days after flowering 15.0 12.5 10.0 C D 0 0 25 50 75 100 125 150 175 200 Days after flowering FW mgg -1 FW mgg -1 chinensis (kiwifruit) population.” Euphytica 138(2): 185-195. Crisosto, C. H. and G. M. Crisosto (2001). “Understanding consumer acceptance of early harvested ‘Hayward’ kiwifruit.” Postharvest Biology and Technology 22(3): 205-213. Harker, R. (2004). “Consumer evaluation of taste and fl avour: ZESPRI TM GOLD and ZESPRI TM GREEN.” New Zealand Kiwifruit Journal 166: 5-9. Harman, J. E. and B. McDonald (1989). “Controlled atmosphere storage of kiwifruit. Effect on fruit quality and composition.” Scientia Horticulturae 37(4): 303-315. MacRae, E.A.; Lallu, N.; Searle, A.; and Bowen, J. (1989). “Change in the softening and composition of kiwifruit (Actinidia Deliciosa) affected by maturity at harvest and postharvest treatments.” J. Sci. Food and Agric. 49, 413-430. Marsh, K., S. Attanayake, et al. (2004). “Acidity and taste in kiwifruit.” Postharvest Biology and Technology 32(2): 159-168. 7.5 5.0 2.5 0.0 0 25 50 75 100 125 150 175 200 10.0 7.5 5.0 2.5 Days after flowering 0.0 0 25 50 75 100 125 150 175 200 Days after flowering GREEN GOLD Figure 4: Changes in acid concentrations in ZESPRI TM GREEN and ZESPRI TM GOLD kiwifruit during fruit development. A. Total acids, B. Citric acid, C. Quinic acid and D. Malic acid Marsh, K. B., E. N. Friel, et al. (2006). “Perception of fl avour in standardised fruit pulps with additions of acids or sugars.” Food Quality and Preference 17(5): 376-386. Richardson, A. C., K. B. Marsh, et al. (2004). “High growing temperatures reduce fruit carbohydrate and vitamin C in kiwifruit.” Plant, Cell & Environment 27(4): 423-435. Tombesi, A., Antognozzi, E, et al. (1993). “Infl uence of light exposure on characteristics and storage life of kiwifruit.” New Zealand Journal of Crop and Horticultural Science 21: 85-90. Woodward, T and Clearwater, M (2007). “Sweet and sour kiwifruit: the relationship between Hayward acidity and dry matter content.” New Zealand Kiwifruit Journal September/October 2007: 34-36. ■
- Page 1 and 2: Thirsty vines Summer girdling Compo
- Page 3 and 4: 4 contributors BILL SNELGAR Bill Sn
- Page 5 and 6: 6 GRANT THORP Dr Grant Thorp is a H
- Page 7 and 8: 8 Statistic December January Februa
- Page 9 and 10: 10 Fruit dry matter (%) Soluble sol
- Page 11 and 12: 12 SUMMARY We now have an indicatio
- Page 13 and 14: 14 Orchard Control Dry matter (%) C
- Page 15 and 16: 16 Operators should also avoid cutt
- Page 17 and 18: Technical Review Advertisement / Ad
- Page 19 and 20: 20 Gearing up ‘Hort16A’ Returns
- Page 21 and 22: 22 Table 2. Maturity attributes of
- Page 23 and 24: 24 Active fungal biomass (ug/g) Fig
- Page 25 and 26: 26 Hayward’s first priority: Shoo
- Page 27 and 28: 28 regrowth developed larger leaves
- Page 29 and 30: 30 Location Soil % C % N C:N Nelson
- Page 31 and 32: 32 Mineral N (mg/kg) Figure 2. Chan
- Page 33 and 34: 34 Resolving labour shortages - Is
- Page 35 and 36: 36 Perceptions of the RSE Advantage
- Page 37 and 38: 38 Organic O Marketing 2007 Tom McL
- Page 39 and 40: 40 Customers are Impressed with tas
- Page 41: 42 The Th flavour fl seesaw: balanc
- Page 45 and 46: 46 Producing country On Orchard Pos
- Page 47 and 48: 48 optimise their current managemen
- Page 49 and 50: 50 Figure 2: Levels of actinidin en
- Page 51 and 52: 52 NZKGI making its pledge in isola
- Page 53 and 54: 54 Image provided by the NOAA/ESRL
- Page 55 and 56: 56 Sea Surface temperature anomaly
- Page 57 and 58: 58 The Taste ZESPRI TM programme wa
- Page 59 and 60: 60 were either completely unconvinc
- Page 61: 62 Orchard productivity remains a k
44<br />
aroma compounds. Dry Matter is a good<br />
indicator of a fruit’s taste potential. Both<br />
sugars and acids levels increase with<br />
increasing fruit DM, however it is the balance<br />
between the two and the type of acids<br />
present (quinic, citric and malic) that gives<br />
consumers their overall impression of fruit<br />
taste. Widely varying total acid levels and<br />
the proportion of different acids present in<br />
Actinidia germplasm give some potential to<br />
create novel fl avours through varying<br />
acid:sugar ratios in new cultivars.<br />
Environmental and fruit storage conditions<br />
as well as management techniques can all<br />
affect fruit fl avour, either by changing both<br />
DM and acidity, or by more specifi c effects<br />
on acidity alone.<br />
ACKNOWLEDGEMENT<br />
This research was funded by the New<br />
Zealand Foundation for Research, Science<br />
and Technology Contract No. C06X0403.<br />
REFERENCES<br />
FW<br />
mgg -1<br />
FW<br />
mgg -1<br />
Cheng, C. H., A. G. Seal, et al. (2004).<br />
“Inheritance of taste characters and fruit<br />
size and number in a diploid Actinidia<br />
A B<br />
65<br />
60<br />
55<br />
50<br />
45<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
0 25 50 75 100 125 150 175 200<br />
50<br />
40<br />
30<br />
20<br />
10<br />
Days after flowering<br />
15.0<br />
12.5<br />
10.0<br />
C D<br />
0<br />
0 25 50 75 100 125 150 175 200<br />
Days after flowering<br />
FW<br />
mgg -1<br />
FW<br />
mgg -1<br />
chinensis (kiwifruit) population.” Euphytica<br />
138(2): 185-195.<br />
Crisosto, C. H. and G. M. Crisosto (2001).<br />
“Understanding consumer acceptance of<br />
early harvested ‘Hayward’ kiwifruit.”<br />
Postharvest Biology and Technology 22(3):<br />
205-213.<br />
Harker, R. (2004). “Consumer evaluation of<br />
taste and fl avour: ZESPRI TM GOLD and<br />
ZESPRI TM GREEN.” New Zealand Kiwifruit<br />
Journal 166: 5-9.<br />
Harman, J. E. and B. McDonald (1989).<br />
“Controlled atmosphere storage of kiwifruit.<br />
Effect on fruit quality and composition.”<br />
Scientia Horticulturae 37(4): 303-315.<br />
MacRae, E.A.; Lallu, N.; Searle, A.; and<br />
Bowen, J. (1989). “Change in the softening<br />
and composition of kiwifruit (Actinidia<br />
Deliciosa) affected by maturity at harvest<br />
and postharvest treatments.” J. Sci. Food<br />
and Agric. 49, 413-430.<br />
Marsh, K., S. Attanayake, et al. (2004).<br />
“Acidity and taste in kiwifruit.” Postharvest<br />
Biology and Technology 32(2): 159-168.<br />
7.5<br />
5.0<br />
2.5<br />
0.0<br />
0 25 50 75 100 125 150 175 200<br />
10.0<br />
7.5<br />
5.0<br />
2.5<br />
Days after flowering<br />
0.0<br />
0 25 50 75 100 125 150 175 200<br />
Days after flowering<br />
GREEN GOLD<br />
Figure 4: Changes in acid concentrations in ZESPRI TM GREEN and ZESPRI TM GOLD kiwifruit during fruit development. A. Total acids, B. Citric acid, C. Quinic acid<br />
and D. Malic acid<br />
Marsh, K. B., E. N. Friel, et al. (2006).<br />
“Perception of fl avour in standardised fruit<br />
pulps with additions of acids or sugars.”<br />
Food Quality and Preference 17(5):<br />
376-386.<br />
Richardson, A. C., K. B. Marsh, et al. (2004).<br />
“High growing temperatures reduce fruit<br />
carbohydrate and vitamin C in kiwifruit.”<br />
Plant, Cell & Environment 27(4): 423-435.<br />
Tombesi, A., Antognozzi, E, et al. (1993).<br />
“Infl uence of light exposure on characteristics<br />
and storage life of kiwifruit.” New Zealand<br />
Journal of Crop and Horticultural Science<br />
21: 85-90.<br />
Woodward, T and Clearwater, M (2007).<br />
“Sweet and sour kiwifruit: the relationship<br />
between Hayward acidity and dry matter<br />
content.” New Zealand Kiwifruit Journal<br />
September/October 2007: 34-36. ■
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