First crop cactus pear cv "Gialla" fruits harvested the 15th of September were wrapped with

a 19 mm thick film or left unwrapped and then divided into two lots, of whom one was immediately stored at 17°C and 60% relative humidity (RH) for 2 or 4 weeks, while the

other one before being stored at the same conditions, was conditioned at 36°C and 90% RH for 36 hours. At each inspection time fruit were checked for incidence of decay, overall appearance and presence of dermatosis. High temperature conditioning, although not

detrimental, had a negative effect on overall appearance and dermatosis. Dermatosis appeared in the form of brown spots on the peel similar to the symptoms of chilling injury

previously described by other authors. The incidence of decay was higher in conditioned fruits than in nonconditioned ones. Plastic film had a positive effect in reducing ageing and dermatosis, while promoted microorganism development. Neither the plastic film nor the

curing treatment had important influence on chemical parameters, while significant was the

effect of the storage period on pH, which changed from 5.95 of harvest to 6.3 after 4

week's storage, and titratab1e acidity (% citric acid), which decreased from 0.077% of

harvest to 0.045% at the end of the storage period. In conclusion, the results show a very

positive contribution of the plastic film in maintaining the initial quality of the fruits, in

fact at the end of the trial the wrapped fruit appeared as fresh as at harvest, while no positive influence was exerted by the cwing treatment

Agabbio, Mario Carlo Salvatore

D'Aquino, Salvatore

Molinu, Maria Giovanna

Mura, Domenico

Piga, Antonio <1965-    >

UnissResearch

European cooperation in the field of scientific and technical research 
COST 914 COST 915 
Joint Workshop 
Non Conventional Methods for the Control 
of Postharvest Disease and 
Microbiological Spoilage 
Belgium 
Czech Republic 
Denmark 
Estonie 
Germany 
Greece 
Spain 
France 
Croatia 
Ireland 
Iceland 
Italy 
Luxembourg 
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European Commission 
EUR 18514 EN 
Malta 
Netherlands 
Norway 
Austria 
Poland 
Portugal 
Romania 
Switzerland 
Slovenia 
Slovak Republic 
Finland 
Sweden 
Turkey 
United Kingdom 
RESPONSE OF CACTUS PEAR FRmT TO mGH TEMPERATURE 
CONDmONING AND FILM WRAPPING 
D'Aquino S.·, Piga A., Agabbio M •• , Molinu M G., and Mwa D. 
• Istituto per Ia Fisiologia della Maturazione e della Conservazione del Frutto delle 
Specie Arboree Meditenanee - CNR ... Via dei Mille 48, 07100 Sassari, Italy . 
•• Dipartimento di Scienze Ambientali Agrarie c di Biotecnologie Agro .. aIimentari -
UniversitA degli Studi ... Viale ItaIia 39- 07100 Sassari, Italy 
Summary 
First crop cactus pear cv "GiaI1a" fruits harvested the 15th of September were wrapped with 
a 19 mm thick film or left unwrapped and then divided into two lots, of whom one was 
immediately stored at 17°C and 60% relative humidity (RH) for 2 or 4 weeks, while the 
other one before being stored at the same conditions, was conditioned at 36°C and 90% RH 
for 36 hours. At e8ch inspection time fruit were checked for. incidence of decay, overall 
appearance and presen~ of dermatosis. Hi8h .temperature conditioning, although not 
detrimental, had a negative effect on overall appearance and dermatosis. Dermatosis 
appeared in the form of brown spots on the pee~ similar to the symptoms of chilling injury 
previously described by other authors. The incidence of decay was higher in conditioned 
fruits than in nonconditioned ones. Plastic film bad a positive effect in reducing ageing and 
dermatosis, while promoted microorganism develOpment. Neither the plastic film nor the 
cwing treatment had important influence on chemical parameters, while significant was the 
effect of the storage period on pH, which cbariged from 5.95 of harvest to 6.3 after 4 
week's storage, and titratab1e acidity (% citric ·acid), which decreased from 0.077% of 
harvest to 0.045 % at the end of the storage periOd. In conclusion, the results show a very 
positive contribution of the plastic film in maintaining the initial quality of the fruits, in 
fact at the end of the trial the wrapped fruit· appeared as fresh as at harvest, while no 
positive influence was exerted by the cwing treatment. 
Key word: Chemical parameters, decay, dermatosis, Opuntis fiCUS-indica MilL,. overall 
appearance. 
Introduction 
Cactus pear is a very high perishable tropical fruit, whose postharvest life, if stored at 
the optimal temperature, is of about 2-4 weeks [17;18]. In filet, at temperatures of 
refrigeration close to ooe, which should be suitable to slow down ageing and to delay 
micro-organjsms development, fruits manifest evident symptoms of chilling injury in the 
form of dermatosis, alteration of the normal physiological activity, and progressive 
weakening and lesions of the tissue. Consequently, after the removal from the chilling 
temperatures to shelf-life conditions the fruit show an increased susceptibility to decay and 
a reduction of postharvest life. Although the use of high temperature conditioning has been 
mainly developed to disinfest fruit from insects (i. g. Caribbean fruit fly) and to control 
fungal disease [13], studies on physiological aspect of heat treatments have shown some 
positive effects on postharvest physiology of fruit. 
Superficial scald, a physiological disorder of apples that occurs dwing storage, was 
inhibited in heated apples [14]. Softening of the flesh, increase in sugar/acid ratio, 
263 
enhanced colour development, and augmentation in respiratory activity and- ethylene 
production, which are the most striking aspects of the ripening process in climacteric fruits, 
are often attenuated by exposure to high temperatW'es [3;7;8"!);II] thus allowing the fruits 
to maintain their quality longer during the shelf-life at 200e [10]. In citrus fruit combining 
high temperature conditioning with film plastic has helped to reduce the incidence of decay 
and to slow down ageing and physiological deterioration even for several weeks at sbelf-
life conditions, without refrigeration [1;6]. 
Objective of our experiment was to evaluate if the combination of the treatments of high 
temperature conditioning with film wrapping was suitable to maintain the overall quality of 
cactus pear fruits over a period of time sufficient to let the fruit be commercialised. 
Materials and Methods 
Fruit of cactus pear (Opuntiaficus-indica MilL) of the cuhivar "Gialla" were harvested 
the ISth of September in the experimental station of the CNR in Oristano. 
From July to until 20 days before harvesting the plantation was treated three times with 
Dimethoate (100 gllOO 1) and cupric oxychloride (300 g 1100 1) to prevent Mediterranean 
fruit fly infestation and protect the plants from bacterial and fungi infections. 
After harvesting, half of the fruit were sealed with a 19 J.Un thick heat shrinkable film 
(Cryovac), while the remaining halfwas-left unwrapped. Soon after half of the unwrapped 
fruit and half of the unwrapped ones were put in storage at 17°e and 6()O/O relative humidity 
(RH) for 2 or 4 weeks, while the remaining half of each group before storage were exposed 
at 36°C and 9()OA RH for 36 hours. 
At each inspection time the fruits were checked for overall appearance, alteration of the 
peel (dermatosis), and the presence of decay, expressed as percentage of rotten fruits. In 
particular, overall appearance was evaluated on the basis of a scale ranging from 5 to 1, 
were S = fiuit very fresh as at harvest; 3 = fruit still sufficiently fresh to be commercialised, 
and 1 = fruit very aged. In relation to the intensity of dermatosis, which appeared in the 
form of brown staining of the rind as previously described by ehessa and Barbera [4], fiuit 
were classified into 4 categories, with 1 = fruit free of any defect; 2 = presence of few 
brown spots less than 1 mm in diameter; 3 = presence of several brQwn spots spread out all 
over the sur1Bce of the 1h1it and often coalescing to form larger depressed areas. In addition 
the chemical analysis (pH, titratable acidity and TSS, as OSrix), in the juice extracted from 
the flesh, were carried out either at harvest or after 2 or 4 weeks of storage. 
Data were analysed by analysis ofvarlance, and the means were separated by the LSD test. 
Results 
The amount of rotten fruit increased during the time in storage, changing from 2.7S 
after 2 weeks of storage to S.S % after-4 weeks (data not shown). The symptoms showed 
by most of the rotten fruits appeared as a watersoaked area, starting from the stem end and 
spreading downwards, with the affected zones asswning a slight brown colour. No 
characteristic structure of fungi microorganism appeared on the surface of the affected 
areas, and only sporadically some mould was detected, probably due to secondary 
infections. In previous experiments other researchers have ~rted a rich miscellaneous of 
species of microorganism affecting cactus pear fruit after harvest [2;4;5]; maybe the 
treatment with cupric oxychloride gave a positive contribution in reducing the incidence of 
decay. The conditioned fruit reported a higher incidence of decay than the control one, 
either after 2 weeks of storage or 4 weeks (Fig. I). Our results are in contrast with those 
reported by Schirra et al. [IS], who relieved a significant reduction of decay development 
in fruit conditioned at 38°e for 24 hoW'S. The plastic film also had a promoting effect on 
264 
decay developme~ and the highest losses were recorded in the group, which received the 
combination of the wrapping-heating treatments. The overall appearance of heated fruit 
worsened at a faster rate than the control (Fig.2). On the other hand the results related to 
the influence of the plastic :film were very positive, confirming those previously found by 
Piga et al.[14], but the wrapped fruit which were conditioned after 4 weeks of storage 
appeared less fresh than those which received only the wrapping treatment. 
Dermatosis, in the form of brown depressed areas varying in size from little pits to larger 
spots, similar to those indicated by other investigators [4;5;14;15;16] as chilling injury 
symptoms, appeared since the 2815 week of storage, and interested an increasing number of 
fruits after 4 weeks. The conditioned fruit reported always a higher incidence of these 
symptoms than the control (Fig. 3), even if these differences were not significant. In 
wrapped fruit, on the other hand, this alteration of the rind appeared in a slighter form than 
in nonwrapped ones. Moreover, while in nonwrapped :fruit the affected areas proceeding 
with the remgeration increased in size and assumed a dark-brown colo~ioD, the wrapped 
fruit manifested little pits, which never became depressed and remained slight in colom. 
The treatments had no substantial effect on the evolution of the chemical parameters (Tab. 
1). Regarding the influence of the storage period, TSS and vitamin C underwent few 
changes during the 4 weeks of the 1rial, while the most important variations interested the 
pH and the titratable acidity, which, respectively, increased from 5.95 to about 6.4 and 
decreased from 0.077% to ·0.040010 respectively at harvest and after 4 week of storage. 
Discussion and ConclusioDs 
The objective of our experiment was to verify if the combination of film wrapping and 
high temperature conditioning was able to reduce both microbiological and physiological 
deterioration of "agostani" cactus pear fruits, thus allowing to store the fruit at shelf-life 
conditions for a period of 2 or 4 weeks without refrigeration. The resu1ts obtained are 
positive only for the treatment with the plastic film. The curing at high temperature 
conditioning gave no positive contribution in reducing decay and ageing of the fruit. On 
the contrary, although not detrimental and not always significant, the effect of high 
temperature conditioning was negative either in nonwrapped fruit or in wrapped one. Since 
the fruit ripen continually ftom the first week of August to until December, dwing 
different climatic conditions, it is possible that the exposure to heat gives different 
responses in relation to the harvesting period. Heating, on the other hand, might have 
different physiological influences on fiuit tissue, and the stress of beating might result 
beneficial, in the case of cactus pear only when fruit are stored at low temperatures. We 
believe that the influence of high temperature conditioning on cactus pear need further 
investigations. Before concluding, we want to emphasize the unexpected development of 
dermatosis, which resembles the chilling injury symptoms previously described by other 
authors [4;5;14;15;16]. We did not expect something like that in fruit stored at 17°C. What 
can be speculated from these results is that the little, invisible wounds caused by the tiny, 
almost invisible spines, underwent a high transpiration rate and, consequently, desiccating, 
evolved towards a symptom similar to chilling injury. The question arises ifwhat so &r bas 
been classified as a chilling injury symptom is a really consequence of low temperatures or 
a physiological alteration caused by other &ctors differing from chilling temperatures, 
whose appearance, in some way is helped by exposure at low temperatures. 
265 
DECAY 
12 
~10 QDCNT P<O.05 .HT 
::» 
• FILM b b 
.:t:a 
.IL 
.FlLM-HT 
Z6 W b 54 
.:t:2 
';I. 
0 
2WEB<S 4V'e<S 
STORAGE PERIOD 
Figure 1 - Effect of treatments on incidence of decay after 2 or 4 weeb of storage at 17°C 
and 600,,6 relative humidity. Vertical bors indicale SE (n = 100). 
OVERALL APPEARANCE 
.CNT P<O.05 b b d .C 5 
aHr 8 a 0= 14 • FILM 
i3 • FILM 
~2 
li 
1 
0 
HARVEST 2WB:1<S 4VVEB<S 
STORAGE PERIOD 
Figure 2 - Overall appearance as affected by the treatments after 2 or 4 weeb of storage 
at 17°C and 6()o,A, relative humidity. Vertical bara indicate SE (90< n<lOO). 
266 
DERMATOSIS 
4 
P<O.05 c c 3.5 
II: 3 w 
ID 2.5 :E 
:J 2 Z 
t1 1.5 Q 1 ~ 
0.5 
0 
2 WEEKS 4 WEEKS 
STORAGE PERIOD 
Fig. 3 - Effect of the treatments on alteration of the peel (dermiltosis) after 2 or ", weeh of 
storage at 170C and 6(JOA, relative humidity. Vertical bars represent SE (90< n <100) 
Tab. 1 - Effect of treatments on chemical panmeten after 2 or .. weeki of 
storage at 17°C and 60 % relative humidity. 
STORAGE pH TITRATABLE 
PERIOD ACIDI1Y 
2 Weeks Storage 
Cootrol 
Hf 
Film 
Film-Hf 
4 Weeks Stcnge 
5.95 
6.03&-
6.12& 
S.99a 
620b 
(% citric acid) 
0.077 
0.063a 
0.062a 
0.063a 
0.0608 
TSS 
(0Jkix) 
14.2 
13.6a 
13.4a 
I3.3a 
13.3a 
VITAMIN 
C. 
(mg/l00al 
31.75 
31.43. 
30.06& 
29.9Oa 
29.13., 
Cantrol 6.24& 0.043. 13.1. 30.43& 
Hf 6.31ab 0.041a 12.9&· 30.07. 
Film 6.39b 0.040a 12.9& 29.44&, 
Film-Hf 6.41b 0.039& 13.2a: 29.23. 
• Means separation in colfIIirM for eoch storage period by 1M LSD lUI « 1M "" level. 
Acknowledgements 
Research supported by the National Research Council of Italy CNRIProg. Spec. 
"Agroindustria" -1st. Naz. Coontin..- The authors contributed equally to this study. 
References 
(1) BEN-YEHOSHUA S., 1990. New developments in applying individual seal packaging 
for improved handling of 1iuits and vegetables. Proc. Int. Citro Symp. GlIsngzboU, 
China, Nov. 5-8, 1990,757-771. 
267 
(2) BERGER H. S., ORlUZAR X. R., AUDA C. M., LIZANA L. A Mo, Y 
RESZCZY'NSKY A. P., 1978. Conservation de tunaS (Opuntia ficus-indica) en 
almacenaje refiigerado. Inv. Agricola (Chile) 4:21-24. 
(3) BIGOS M. S., WOODSON A R., and HANDA A K., 1988. Biochemical basis of high 
temperature inhibition of ethylene biosynthesis in ripening tomatoes fruits. PhisioL 
Plant. 72:572-578. 
(4) CHESSA I., and BARBERA G., 1984. Indagine sulla ftigoconservazione dei frutti 
delIa cv Gialla di ficodindia. Frutticohura XLVI (8):57-61. 
(5) D'AQUINO S~, AGABBIO M, PIGA A, PILO G., and SASSU M. M, 1996. 
Influenza di alcuni fungicidi sullo sviluppo dei marciumi in frutti di fico d'India 
frigoconservati. Italus Hortus 3(4):32-37. 
(6) D'AQUINO S. PIGA A, AGABBIO M., and TRIBULATO E., 1996. Improvement of 
the postharvest keeping quality of"Miho" satsuma fruits by heat, semperftesb and film 
wrapping. Adv. Hort. set, 10:15-19. . . 
(7) EAKS I., 1978. Ripening, respiration, and ethylene Foduction of "Hass" avocado fruits 
at 20°C to 40°C. J. Amer. Soc. Hort. Sci. 103:576-578. 
(8) KERBEL E. L., MITCHELL F. G., and MAYER G., 1987. Effect of postharvest beat 
treatments for insect co~l on the quality and market life of avocado. HortScience 
22:92-94.' . 
(9) KLEIN J. D., 1989. Ethylene biosynthesis in heated treated apples, p.184-190. In H. 
CLUSTERS, M. DE PROFT, R. MARCELLE, and M. VAN POUCHE (eds). 
Biochemical and physiological aspects of ethylene production in lower and higher 
plants. Kluwer, Dordrecht, The Netherlands. 
(10) KLEIN J. D., and LURIE S., 1992. Heat treatments for improved postharvest 
quality ofhorticuhural crops. HortThechnology 2(3)316-320. 
(11) KLEIN J. D., LURIE S., and BEN-ARIE R., 1990. Quality and cell wall 
components of "Anna" and "Granny Smith" apples treated with heat, calcium, and 
ethylene. J. Amer. Soc. Hort. Sci. 115:954-958. 
(12) LURIE S., KLEIN J. D., and BEN-ARm R., 1991. Prestorage heat treatment delays 
development of superficial scald on "Granny Smith" apples. HortScience 26:166-167. 
(13) PAULL R. E., 1990. Postharvest heat treatments and fruit ripening. Postharvest 
News and Information 1(5):355-363. . 
(14) PIGA A., D'AQUINO S., AGABBIO M., and SCHIRRA M, 1996. Storage life and 
quality attributes of cactus pears cv "Gia1la" as affected by packaging. Agr. Med. 
126:423-427. . 
(IS) SCHIRRA M., BARBERA G., LA MANTIA T., and McDONALD RE., 1996. Hot 
dips and high-temperature conditioning to improve shelf quality of late-crop cactus 
pear fruit. Trop. Sci. 36:159-165. 
(16) SCHIRRA M., AGABBIO M.; D'AQUINO S., and McCOLLUM T., 1997. 
Postharvest heat conditioning effects on early ripening "Gialla" cactus pear :fruit. 
. 32(4)702-704. 
(17) SNOWDON A L.,.l990. A colour atlas of post-harvest disease and disorders of 
fruit and vegetables. VoL1: General introduction and fruits. Published by Wolfe 
Scientific Ltd. London, England. 
(18) TESTONI A.; and ZERBINI P. E., 1990. Conservazione del fico d'india in 
atmo$~ nornWe e controllata. Annali I.V.T .P.A VoLXXI:131-139. 
268 


Response of cactus pear fruit to high temperature conditioning and film wrapping

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