Effect of Edible Coatings from Aloe vera gel on Citrus sinensis during Ambient storage


Extension of the shelf life of orange fruits continues to be a challenge in Nigeria. The search forsafe, healthy and environmental friendly treatments has led to increased interest in research into edible and biodegradable films and coatings. In this work, the use of Aloe vera gel as a coating to extend the shelf-life of orange fruits was investigated. The oranges were stored at ambient temperature (27+2oC) and at 50-60% relative humidity for five weeks. During ambient storage, uncoated fruits showed 43.11% and 60.63 % increases in total soluble solids and reducing sugar contents respectively. Rapid weight loss and loss of firmness were also observed. The above parameters which are related to post- harvest quality loss were however significantly controlled in the oranges coated with A. vera gel. Percent increase in total soluble solids 56.89% and reducing sugar contents 39.36% were observed. The storability of orange fruits was extended by five weeks. It was concluded that A. vera gel used as a coating for orange could serve as an alternative to post-harvest chemical treatments.
J. Agric. Res. & Dev. 11(1). Copy@2012. Faculty of Agriculture, University of Ilorin
Effect of Edible Coatings from Aloe vera gel on Citrus sinensis during
Ambient storage.
1Nigerian Stored Product Research Institute, Km 3 Asa Dam Road, P.M.B. 1489, Ilorin,
2University of Ilorin, Department of Agronomy, P.M.B.1515, Ilorin, Kwara State.
3University of Ilorin, Department of Biochemistry, P.M.B.1515, Ilorin, Kwara State
4Ladoke Akintola University of Technology, Department of Pure and Applied Biology P.M.B
4000, Ogbomoso, Oyo State.
Extension of the shelf life of orange fruits continues to be a challenge in Nigeria. The search for
safe, healthy and environmental friendly treatments has led to increased interest in research into
edible and biodegradable films and coatings. In this work, the use of Aloe vera gel as a coating to
extend the shelf-life of orange fruits was investigated. The oranges were stored at ambient
temperature (27+2oC) and at 50-60% relative humidity for five weeks. During ambient storage,
uncoated fruits showed 43.11% and 60.63 % increases in total soluble solids and reducing sugar
contents respectively. Rapid weight loss and loss of firmness were also observed. The above
parameters which are related to post- harvest quality loss were however significantly controlled in
the oranges coated with A. vera gel. Percent increase in total soluble solids 56.89% and reducing
sugar contents 39.36% were observed. The storability of orange fruits was extended by five weeks.
It was concluded that A. vera gel used as a coating for orange could serve as an alternative to
post-harvest chemical treatments.
Keywords: Shelf life, Orange Fruits, Aloe vera
The sweet orange (Citrus sinensis (L.) Osbeck), is the most commonly grown
tree fruit in the world (Morton, 1987). Citrus fruits are produced all around the
world and world citrus production in selected major producing countries in
2005/2006 is 72.8 million metric tons. Citrus fruits are said to be the first crops
in the international trade in terms of values (CIAC, 2002).
Edible coatings are thin layers of edible material applied to the product surface
in addition to or as a replacement for natural protective waxy coatings and
provide a barrier to moisture, oxygen and solute movement for the food (Smith
et al., 1987; Nisperos-Carriedo et al., 1992; Guilbert et al., 1996; Lerdthanangkul
and Krochta, 1996; Avena-Bustillos et al., 1997; McHugh and Senesi, 2000). They
are applied directly on the food surface by dipping, spraying or brushing to
create a modified atmosphere (Guilbert et al., 1996; Krochta and Mulder-
Johnston, 1997; McHugh and Senesi, 2000).
Recently there has been increased interest in using Aloe vera gel as an edible
coating material for fruits and vegetables driven by its antifungal activities,
biodegradability and eco-friendliness. (Saks et al., 1995; Martinez-Romero et al.,
2003 ; Rodriguez de Jasso et al., 2005). Aloe vera based edible coatings have
been shown to prevent loss of moisture and firmness control, respiration rate
and maturation development, delay oxidative browning, and reduce
microorganism proliferation in fruits such as sweet cherry, table grapes and
nectarines (Valverde et al.,2005; Martinez-Romero et al.,2006; Ahmed et
al.,2009) .
Preparation of Aloe vera gel (edible coatings):
Matured leaves of Aloe vera plant were harvested and washed with a mild
(25%) chlorine solution.. Aloe vera gel matrix was then separated from the
outer cortex of leave and this colorless hydroparenchyma was grounded in a
blender .The resulting mixture was filtered to remove the fibers. The liquid
obtained constituted fresh Aloe vera gel. The gel matrix was pasteurized at 70oC
for 45min. For stabilization, the gel was cooled immediately to an ambient
temperature and ascorbic acid (1.9 - 2.0g L-1) was then added. Citric acid (4.5 -
4.6gL-1) was added to maintain the pH at 4. The viscosity of the stabilized Aloe
vera gel and its coating efficiency was improved by adding 1% commercial
gelling agent before use as coating agent. It was later stored in brown Amber
bottle to prevent oxidation of the gel (He et al.,2005).
Source of oranges: Freshly harvested oranges were procured from a local
market in Ilorin, Kwara State, Nigeria. They were selected on the basis of size,
color and absence of external injuries. Fresh leaves of Aloe vera were obtained
from the garden of the Nigeria Stored products Research Institute, Ilorin.
Surface preparation of the oranges: Surface preparation was primarily to
remove all contaminants that would hinder proper coating adhesion and to
render a sound clean substrate, suitable for firm bonding. Surface sterilization
of the oranges was carried out by soaking them in 25% hypochlorite solution for
two minutes.
Effect of Aloe vera gel on Citrus sinensis during storage
To (control):- Untreated oranges.
T1:- Oranges coated with Aloe vera gel.
The treated and untreated oranges were packed in small plastic baskets and
each basket contained 20 orange fruits. The baskets were stored at ambient
temperature (27+2oC) and at 50-60% relative humidity .Physiochemical analysis
were carried out from 1-5weeks after coating.
Total soluble solids (TSS):- Total soluble solids (TSS) were measured by the
method described by Dong et al. (2001) .Individual orange fruit from each of the
treatment were ground in an electric juice extractor for fresh prepare juice.
Soluble solids content were measured using T/C hand refractometer in Brix%
(Model 10430 porx-reading 0.30 ranges Bausch and Lomb CO. Calif., USA.
Firmness: - Firmness was measured as the maximum penetration force (N)
reached during tissue breakage, and determined with a 5 mm diameter flat
probe. The penetration depth was 5 mm and the cross-head speed was 5 mm
s_1 using a TA-XT2 Texture Analyzer (Stable Micro Systems, Godalming, UK), MA.
Oranges were sliced into halves and each half was measured in the central zone.
Water content: - The water content of the orange fruit was determined using
the following equation.
Water content (%) 100 x M1-M2
Where: M1 = Mass of sample before drying in g.
M2 = Mass of sample after drying, in g.
Reducing sugar
The reducing sugar of oranges was determined using Fehling’s method
(Mendham et al., 2000 ) while the ascorbic acid content was measured using 2,
5-6 dicholorophenol indophenols’ method (A.O.A.C 1994).
The results of this investigation are means of six measurements. To verify the
statistical significance of all parameters the values of means ± S.E. were
% water loss
Duration (in weeks)
Fig 1: Effect of Aloe vera gel on water content of orange fruit
Total soluble
Duration( in weeks)
Fig 2: Effect of Aloe vera gel on T S S of orange fruits during storage at
Reducing sugar
Duration ( in Weeks)
Fig 3:Effect of Aloe vera gel on Reducing sugar of orange fruits during
storage at ambient temperature
Duration (in weeks)
Fig 4:Effect of Aloe vera gel on Firmness of orange fruits during
storage at ambient temperature
Vc (mg/ml -1)
Duration in weeks
Fig5:Effect of Aloe vera gel on Vitamin C of orange fruit during
ambient storage
Effect of Aloe vera gel on Citrus sinensis during storage
Water content
The mean±SE value for the weight loss of coated oranges was 64.09±7.13 while
the mean±SE value for the weight loss of uncoated oranges was 89.65±5.82.
These results are in agreement with those of Mahmoud and Savello (1992) and
Avena-Bustillos et al. (1997) who concluded that coatings and/or films
significantly conserved water content.
Post harvest weight changes in fruits and vegetables are usually due to the loss
of water through transpiration. This loss of water can lead to wilting and
shriveling which both reduce a commodity’s marketability. Edible films and
coatings can also offer a possibility to extend the shelf life of fresh-cut produce
by providing a semi-permeable barrier to gases and water
vapor and therefore, they can reduce respiration, enzymatic browning and
water loss (Guilbert, 1986; Baldwin & Nisperos-CarriedoBaker, 1995).
Total soluble solids (TSS)
The mean ± SE value for the TSS of coated orange was 8.025±0.9 while the the
mean ± SE value for the TSS of uncoated oranges was 6.08±1.63. These results
are in agreement with those of Smith and Stow (1984) who concluded that
coatings and/or films significantly affected TSS.
Soluble solids content of coated and uncoated oranges stored under cold
condition was decreased at the end of the storage period. The loss of soluble
solids during storage period is as natural as sugars which are the primary
constituent of the soluble solids content of a product consumed by respiration
and used for the metabolic activities of the fruits (Özden & Bayindirli, 2002).
The mean±SE value for the reducing sugar of coated oranges was 7.61±0.45
while the mean±SE value for the reducing sugar of uncoated oranges was
4.94±0.92.These results are in agreement with those of Ahmad and Khan (1987),
El Ghaouth et al. (1991) and Li and Yu (2000) and McHugh and Senesi (2000)
who concluded that coatings and/or films significantly affected reducing sugar
content of produce.
The mean±SE value for the firmness of the coated was 3554.33±368.22 while
the mean±SE value for the uncoated was 2708.67±626.19. Lerdthanangkul and
Krochta (1996) also made similar observations and concluded that coatings
and/or films significantly affected firmness of fruits in storage. The softening
process in orange has been reported to be dependent on the increase in
polygalacturonase, ßgalactosidase and pectinmethylesterase activities
(Batisse et al., 1996; Gerardi et al., 2001; Rem´on et al., 2003), being responsible
for fruit quality loss. A. vera treatment significantly reduced the firmness losses
(more than 50%) during ambient storage compared with the control fruits. In
addition, A. vera gel probably had some effects on the reduction of cell wall
degrading-enzymes responsible for orange softening. These results show
beneficial effects of the Aloe vera coating on increasing the orange shelf life,
since it has been postulated that fruit softening and texture changes during the
orange storage determine fruit storability and shelf life as well as reduced
incidence of decay and less susceptibility to mechanical damage (Batisse et al.,
1996; Vidrih et al., 1998).
The mean±SE value for the coated orange for Vitamin C was 6.48±0.50 while the
mean±SE value for the uncoated was 5.41±0.51. Ascorbic acid is lost due to the
activities of phenoloxidase and ascorbic acid oxidase enzymes during storage
past workers (Salunkhe et al., 1991 Weichmann et al. 1985), while studying
green bean, spinach and broccoli, postulated that the lower the oxygen content
of the storage atmosphere, the smaller is the loss of ascorbic acid. The claim
was that the oxidation of Vitamin C was mainly regulated by ascorbic acid
oxidase and other oxidases, most of which had a low affinity for oxygen.
Ascorbic acid content decreased for cherries stored at both ambient
temperature and cold temperatures. Aloe vera gel coatings were effective in
reducing the ascorbic acid loss for both storage conditions (Fig. 5). At the
ambient temperature, the ascorbic acid contents of Aloe vera gel coated orange
were significantly different from the control orange. The reduction of ascorbic
acid loss in coated orange was due to the low oxygen permeability of Aloe vera
gel coating which lowered the activity of the enzymes and prevented oxidation
of ascorbic acid.
The effect of low temperature significantly reduced the ascorbic acid loss. This
shows the effect of temperature on the activities of the related enzymes.
Aloe vera gel, applied as edible coating in orange fruit, has beneficial effects in
retarding the ripening process. This treatment was effective as a physical barrier
and thus reduced the weight loss during postharvest storage. In addition, A.
vera gel delayed softening, ascorbic acid and TSS losses and maintained the
quality of the orange fruits.
Effect of Aloe vera gel on Citrus sinensis during storage
AOAC, (1994). Official Methods of Analysis. Association of Official Analytical Chemists. 1111 North
19th Street, Suite 20, 16th Edi. Arlington, Virginia, USA. 22209.
Ahmad M. and Khan I. (1987). Effects of waxing and cellophane lining on chemical quality indices
of citrus fruits. Plant foods for Human Nutrition. 37: 47-57.
Ahmed, J.; Varshney, S.K.; Zhang, J.X.; Ramaswamy, H.S( 2009). Effect of high pressure treatment
on thermal properties of polylactides. Journal of Food Engineering, 93, 308312.
Avena-Bustillos R.J. Krochta J.M. and Saltveit M.E. (1997). Water vapor resistance of red delicious
apples and celery sticks coated with edible caseinate-acetylated monoglyceride films.
Journal of Food Science. 62: 351-354.
Baldwin, E. A., Nisperos-Carriedo, M. O. & Baker, R. A. (1995). Use of edible coatings to
preserve quality of lightly (and slightly) processed products. Critical Review Food
Science Nutrition 35, 509524.
Batisse, C., Buret, M., Coulomb, P.J.,( 1996). Biochemical differences in cell wall of cherry fruit
between soft and crisp fruit. J. Agric. Food Chem. 44, 453457.
CIAC, (2002). Strategic Investment Plan (Horticultural Australia). An https documents available at .
El Ghaouth A. Arul J. Ponnampalam R. and Boulet M.( 1991). Chitosan coating effect on storability
and quality of fresh strawberries. Journal of Food Science. 56: 1618-1620.
Guilbert, S. (1986). Technology and application of edible protective films. In Mathlouthi, M. (Ed.),
Food packaging and preservation, p. 371394. London, UK: Elsevier Applied Science.
Guilbert S. Gonterd N, Thibault R, Cuq B (1996). Influence of relative humidity and film
composition on oxygen and CO2 permealbility of edible films. J Agric Food Chem.
Gerardi, C., Blando, F., Santino, A., Zacheo, G.,( 2001). Purification and characterisation of a β-
glucosidase abundantly expressed in ripe sweet cherry (Prunus avium L.) fruit. Plant Sci.
160, 795805.
He, Q.; Changhong, L.; Kojo, E.; Tian, Z(2005). Quality and safety assurance in the processing of
Aloe Vera gel juice. Food Control, 16, 95-104.
Krochta, J. M. and Mulder-Johnston, C. D. 1997. Edible and biodegradable polymer films:
challenges and opportunities. Food Technology 51(2): 61-74.
Li H. and Yu T. (2000). Effect of chitosan on incidence of brown rot, quality and physiological
attributes of postharvest peach fruit. Journal of the Science of Food and Agriculture. 81:
Lerdthanangkul S. and Krochta J.M. (1996). Edible coating effects on post harvest quality of green
bell peppers. Journal of Food Science. 61: 176-179.
Martinez-Romero H, GO Martinez-Andrade, J Contreras-Perez, G Saucedo-Arteaga, L Huerta-
Perez, RI Ramos, J Ramirez-Centeno, LM Meneses-Diaz, and A Chavez-Villasana. (1993).
[Experiences in community participation to promote nutritional education]. [Spanish]
35(6):673-81, Nov-Dec.
Martinez-Romero D. Alhurquerque N. Valverde JM, Guillen F, Castillo S, Valero D. Serrano M.
2006. Postharvest sweet cherry quality and safety maintenance by Aloe vera treatment:
A new edible coating. Postharvest Biology and Technology 39:93-100.
McHugh T.H. and Senesi E. (2000). Apple wraps: A novel method to improve the quality and
extend the shelf life of fresh-cut apples. Journal of Food Science, 65: 480-485.
Mahmoud R. and Savello P.A. (1992). Mechanical properties of and water vapor transferability
through whey protein films. Journal of Dairy Science. 75: 942-946.
Mendham J. Denney R.C. Barnes J.D. and Thomas M. (2000). Vogel’s Textbook of Quantitative
Chemical Analysis, Pearson Education Ltd, England.
Nisperos-Carriedo MO, Shaw PE and Baldwin EA. (1990). Changes in volatile flavor components of
pine apple orange juice as influnced by the application of lipid and composite film. J Agric
Food Chem. 38:1382-1387.
Özden, C. & Bayindirli, L. ( 2002). Effects of combinational use of controlled atmosphere, cold
storage and edible coating applications on shelf life and quality attributes of apples,
European Food Research Technology, 214, 320326.
Rem´on, S., Venturini, M.E., L´opez-Buesa, P., Oria, R.( 2003). Burlat cherry quality after long range
transport, I optimisation of packaging conditions. Inno. Food Sci. Emerg. Technol. 4, 425
Rodrı´guez de Jasso, D.; Herna´ndez-Castillo, D.; Rodrı´guez- Garcı´a, R.; Angulo-Sa´nchez, J. L.
(2005) Antifungal activity in vitro of Aloe vera pulp and liquid fraction against plant
pathogenic fungi. Ind. Crop Prod., 21, 81-87.
Saks, Y.; Barkai-Golan, R(1995). Aloe vera gel against plant pathogenic fungi. PostharVest Biol.
Technol., 6, 159-165.
Salunkhe, D. K., Boun, H. R., Rddy, N. R.(1991). Storage Processing and Nutritional Quality of Fruits
and Vegetables, vol. 1. Fresh Fruits and Vegetables. Boston: CRC Press Inc.
Smith, J.H., A.K. Mallett, R.A.J. Priston, P.G. Brantom, N.R. Worrell, C. Sexsmith and B.J.
Simpson, (1987). Ninety day feeding study in Fischer-344 rats of highly refined petroleum-
derived food-grade white oils and waxes. Toxicol. Pathol., 24: 214-230.
Smith S.M. and Stow J.R. 1984. The potential of a sucrose ester coating material for improving the
storage and shelf-life qualities of Cox’s Orange Pippin apples. Annals of Applied Biology.
104: 383-391.
Valverde JM, Valero D, Martinez-Romero D, Guillen FN, Castillo S, Serrano M. 2005. Novel edible
coating based on aloe Vera gel to maintain table grape quality and safety. Journal of
Agriculture and Food Chemistry 53:7807-7813.
Vidrih, R., Zavrtanik, M., Hribar, J., (1998). Effect of low O2, high CO2 or added acetaldehyde and
ethanol on postharvest physiology of cherries. Acta Hort. 2, 693695.
Weichmann, J. (1985) Postharvest Physiology of Vegetables. New York: Marcel Dekker .
... These unique properties make Aloe vera a candidate for edible coatings to prevent spoilage, reduce microorganism proliferation and maintain the quality of fruit during storage . The Aloe gel coating has been also shown to enhance the post-harvest quality of fruits (Adetunji et al., 2012a;Adetunji et al., 2012b;Adetunji et al., 2013;Benítez et al., 2013;Guillen et al., 2013;Adetunji et al., 2014a). ...
... The faster rate in the TSS increment in the untreated fruits might be due to faster metabolic activities through respiration and transpiration (Rokaya et al., 2016). A researcher reported that the increase in total soluble solids, reducing sugar content, weight loss and loss of firmness was significantly controlled in oranges coated with A. vera gel (Adetunji, 2012). The increase in TSS during the storage may be due to sugar synthesis from organic acid and degradation of cell wall leading to increase in total dissolved solids increase, hydrolytic enzymes or waste water under storage conditions as stated (Nasirifar et al., 2018). ...
... Edible coatings, similar to modified atmosphere packaging, have been shown to protect horticultural products from mechanical damage, transpiration, respiration, and pathogen infection by providing a beneficial semi-permeable film around the fruit (Falguera et al., 2011 ). Edible coatings based on polysaccharides, for example mixtures of starch, chitosan, locust bean gum (Rojas-Argudo et al., 2009), carrageenan and carboxymethyl cellulose (Togrul and Arslan, 2004), aloe vera (Adetunji et al., 2012 ), galactomannans (Cerqueira et al., 2011), and hydroxypropyl methylcellulose (Valencia-Chamorro et al., 2009), have been investigated as a means of improving the storability of citrus fruits. Among them, sodium alginate, a polysaccharide derived from marine brown algae, has played a dominant role due to its unique colloidal properties and its ability to form strong gels in aqueous solutions. ...
Quinoa plant has been recognized as a well-balanced pseudo-cereal which has been identified as an excellent grain due to the presence of excellent constituents like high gluten-free proteins, several minerals, and polyunsaturated fatty acids. This wonderful plant has been recognized to possess several pharmacoactive constituents that could be utilized for the management of several diseases. Furthermore, it is a beneficial pseudo-cereal in celiac patients because it is gluten-free and can easily be digested by celiac patients as well as portends the capability to decrease the threat of heart diseases as well as very strong anti-hypercholesterolemic activity. Therefore, this chapter intends to highlight several pharmacological constituents available in quinoa plant which could be utilized in the treatment of several diseases. Also, more emphasis was laid on the nutritional benefits of quinoa plant as a depository of essential nutrients which could help in the maintenance of the well-being of mankind.
The world population has been stated to increase drastically to nine billion in the year 2020. Therefore, there is a need to search for sustainable solution that could help in mitigating several challenges facing mankind which includes food insecurity and health and environmental hazards. The utilization of quinoa plant as a sustainable biotechnology solution will be a preferred solution to all these highlighted challenges. This chapter provides a general overview on the uses as a next generational plant that could solve food insecurity, health challenges, and maintenance of cleaner environment. Moreover, recent advances in the application of as a depository of pharmacoactive constituents (protein, dietary fiber, vitamins, minerals, essential amino acids, betacyanins, betaxanthins, and flavonoids) and their diverse application in the treatment of several diseases such as diabetes and glycemic index, immune-regulatory activity, hepato-protective, antioxidant activities.
Quinoa (Chenopodium quinoa) has been identified as a unique plant with several benefits that could solve several challenges facing mankind. The application of some recent advances in biotechnological techniques could help toward enhancing the production of important metabolites and nutritional attributes and improve the quality of several products that could be derived from quinoa. It is a source of excellent antioxidant activity along with high values of amino acids, carbohydrates, fatty acids, minerals, phenolic compounds, and saponins. Some of these metabolites possess biotechnological relevance in the production of pharmaceutical, insecticidal, biopesticidal, and nematocidal products. This chapter provides detailed information on the utilization of in vitro tissue culturing for effective production of essential metabolites, while the application of somatic embryogenesis methodology has been identified as significant instrument for effective production of virus-free plants. Furthermore, detailed information on the application of metabolomics together with hyphenated analytical and spectroscopic methodology which included gas chromatography coupled to mass spectrometry, liquid chromatography, and nuclear magnetic resonance spectrometry is provided. Relevance of synthetic biology, informatics, computational biology, and bioinformatics together with nanotechnology on how they could improve some bioactive constituents derived from quinoa plants was also highlighted.
Organic approaches of pest and plant disease control using pesticides need to be seriously evaluated to counter the negative impact of high agrochemical input in conventional agriculture. This approach is possible through utilization of vermiwash and vermicompost extract, products derived from vermiculture and vermicomposting process, respectively. The products contain high variation of compounds rich in beneficial microorganisms, nutrients, vitamins, and growth hormones that serve as biofertilizer and biocontrol agents against diseases and pests. Liquid forms of vermicompost derivatives are more efficient compared to solid forms due to its ability to reach the target area on plant above ground through foliar application and rhizosphere part of plant underground through soil drench. Vermicompost derivatives can be solely used or mixed with solid vermicompost, fertilizer, or any organic material in soil to achieve the best result not only for pest and disease control but more importantly for soil health and plant growth.
A novel edible coating based on carboxymethyl cellulose (1.5%, CMC) containing ethanol extract of Impatiens balsamina L. stems, 0.07% citric acid, 0.5% sucrose ester, 1.0% calcium propionate and 0.5% glycerol was applied to “Xinyu” tangerines to delay their ripening and prolong postharvest life during storage at 5C for 100 days. The addition of IB extract as antifungal components in the CMC coating had an inhibitory effect on mold growth, and the coated treatments significantly decreased decay rate and weight loss, maintained commercial quality and enhanced the activities of antioxidant and defense-related enzymes compared with the uncoated control group. The results suggested that by applying the complex coating, we can delay the ripening and prolong the postharvest life of “Xinyu” tangerines. Edible coatings could be an effective technology for obstructing pathogenic infection and delaying the ripening process of fruits and vegetables during the postharvest storage period. The effectiveness of an edible coating based on 1.5% CMC coating containing IB extract and other film-forming additives, in comparison with CMC coating without IB extract, was applied in “Xinyu” tangerines in order to reduce the rate of decay and maintain the nutritional quality of fruit during postharvest storage. The results showed that complex coating was able to provide a barrier to the pathogen and gas by reducing decay rate and weight loss. Meanwhile, the degradation of the nutritional quality of “Xinyu” tangerines was significantly delayed. The activities of SOD, CAT, POD, PAL and GLU were much higher in the complex coating treatment than in CMC coating alone and the control group. Our results suggest that the complex coating could be explored as a novel and potentially natural edible coating for preserving “Xinyu” tangerines.
Full-text available
Cherries cv. Van were stored in the atmosphere of CO2, N 2, acetaldehyde (AA) vapours and ethanol (ET) vapours at 20°C for 24 hours and afterwards transferred to air at 0°C. Fruits of two different harvest dates (10 - 14 days before commercial harvest date; commercial harvest date) were used. AA and ET accumulated in control (non treated) fruits during ripening. Much more AA and ET accumulated in fruits stored in CO2, N2, AA vapours and ET vapours. CO2 treated fruits accumulated more AA and ET than N2 treated fruits. More AA and ET accumulated in more matured fruits than in less matured fruits. Methanol (ME) accumulated during storing of cherries, its concentration being independent on treatment or storage conditions. Added AA provokes an increase of AA and ET in fruit tissue as well as added ET provokes an increase of AA and ET. Exposure of fruits to AA or ET vapours does not influence fruit ripening. Short exposure of cherries to CO2 or N2 atmosphere inhibits fruit ripening and thus prolong storage life of such perishable fruits as cherries.
Full-text available
The effect of chitosan coating (1.0 and 1.5% w/v) in controlling decay of strawberries at 13°C was investigated as compared to a fungicide, iprodione (Rovral®). Chitosan coating significantly reduced decay of berries (P ≤ 0.05) compared to the control. There was no significant difference between chitosan and fungicide treatments up to 21 days storage. Thereafter, Rovral®-treated berries decayed at a higher rate than chitosan-coated berries. Chitosan-coated berries stored at 4°C were firmer, higher in titratable acidity, and synthesized anthocyanin at a slower rate than Rovral®-treated or nontreated berries. Chitosan coating decreased respiration rate of the berries with a greater effect at higher concentration.
Transglutaminase was used to produce films by polymerization of whey proteins. The reaction mixture consisted of 5% whey protein in pH 7.5 buffered solution under reducing conditions in the presence of Ca2+ ions and glycerol. The water vapor transferability and the percentage of moisture of films were not significantly influenced by the whey protein fraction. Water vapor transferability was inversely related to film thickness. Glycerol concentration of films directly affected film resistance to breakage, moisture content, and resistance to water vapor transferability.
The cell wall differences between crisp and soft cherry fruits are reported. The penetrometric measurements are correlated with the physiological stage of fruits but not with the sensory analysis at maturity. The major difference lies in the degree of polymerization of pectin side chains. A high degree of polymerization produces a rigid cell wall with numerous bonds between the polymers of crisp fruits:  the cells present regular forms. On the contrary, the soft fruits possess fewer interactions between polymers, and consequently, the cells present irregular forms. Keywords: Cherry; pectin; softening; turnover
Five lipid and composite films were tested for their ability to retain volatile flavor components in Pineapple oranges during storage at 21°C. By use of a headspace analysis technique, 15 components were detected and quantified in juice from both coated and uncoated stored fruits. Uncoated fruits showed minor increases in ethanol, methanol, acetaldehyde, hexanol, and cis-3-hexenol during storage for 2 days. The coated fruits showed significant increases in components considered important to fresh orange flavor (acetaldehyde, ethyl acetate, ethyl butyrate, and methyl butyrate). Use of beeswax emulsion and TAL Pro-long alone or in combination was the most effective coating in retaining or increasing volatile components.
A sucrose-ester coating material was tested for its potential as a storage technique and as an extender of the shelf life of apple (cv. Cox's Orange Pippin). Apples treated with 1·25% sucrose ester formulation were stored in air at 3·5°C for up to 5 months. Sucrose ester treatment did not reduce detrimental changes in terms of fruit firmness, yellowing and weight loss but did increase core flush incidence. When applied after storage, the sucrose ester reduced yellowing and loss of firmness and markedly increased internal carbon dioxide levels during a 21 day simulated marketing period. Effects were enhanced with increasing sucrose ester concentrations between 1% and 4%. Sucrose ester did not markedly reduce weight loss in the fruit, did not cause accumulation of alcohol or induce any internal physiological disorders during the simulated marketing period. Treatment of fruit with an external atmosphere containing 8% carbon dioxide, a level similar to that found in fruit treated with 3% sucrose ester, did not have the same effects as 3% sucrose ester on firmness or ground colour changes, suggesting that the effects of the sucrose ester are not solely the result of the raised carbon dioxide level.