Preservation of mango pulp of fruit from Rusitu Valley
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
PAK. J. FOOD SCI., 22(4), 2012: 191-196
ISSN: 2226-5899
Preservation of mango pulp of fruit from Rusitu Valley,
Chimanimani in Zimbabwe
Chakare Benhura1 *, Tungamira Rukuni2, Charity Kadema1, Bonface Mubvakure2, Raymond Nazare3 Power Ernest
Gombiro1, Brian Tokwe1, Evidence Matangi4 and Angeline Madzima2
1
Institute of Food, Nutrition and Family Sciences, University of Zimbabwe P. O. Box MP 167, Mount Pleasant, Harare.
2
Development Technology Centre, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare
3
Department of Soil Science and Agricultural Engineering, University of Zimbabwe, P. O. Box MP 167, Mount Pleasant,
Harare
4
Department of Statistics, University of Zimbabwe P. O. Box MP 167, Mount Pleasant, Harare
Corresponding author: cbenhura@science.uz.ac.zw
ABSTRACT
Rusitu Valley in Zimbabwe produces a lot of mango fruit most of which is lost due to its perishable nature. The fruit is processed into pulp
for preparation of juice and jam. The major problem is that the pulp has a short shelf life due to microbial degradation. The objective of the
work was to find an effective preservation method for pulp from the fruit. The pulp was divided into samples which were treated with
chemical preservatives and untreated ones. Treated samples were preserved with sodium metabisulphite, potassium sorbate, and citric acid
followed by pasteurization at 80 to 90oC. One sample, C0 was not treated with chemical preservatives and was not pasteurized. Total
soluble solids, pH, colour and odour were measured within 21 days. The pH of treated pulp samples decreased with time. The pH of C0
and C1 which were not chemically preserved rapidly decreased within 3 to 4 days. The total soluble solids content of samples S2 and S3
was constant, but decreased with time for the rest of the samples. Unpasteurized pulp retained the yellow colour while heat treated samples
turned yellowish brown. Moulds colonies were observed and stale odours were detected in samples C0 and C1. Samples S1, S2 and S4
which were not pasteurized had a pungent odour. Pasteurized samples S3, S5 and S6 had a cooked mango odour which was not astringent.
Sodium metabisulphite, citric acid, potassium sorbate and pasteurization increased the shelf life and stabilized the sensory properties of the
pulp.
Key words: Mango, preservation, pH, Total soluble solids, Hurdle concept.
produces 170840 tonnes of mango annually (Government
INTRODUCTION
of Zimbabwe Agricultural Report, 2012). Most of the
Mango (Mangifera indica, L) is one of the highly priced fruit is produced at subsistence level by rural
fruit in the tropics. In this context, mango is known as an communities who primarily use it for home consumption.
appreciable fruit due to its pleasant aroma and flavour, Some growers sell their produce to local beverage
whose nutritional value presents high calories and industries and fruit and vegetable industries for export.
vitamin contents, among others (Moraes et al., 2010; Other farmers harvest ripe and semi-ripe fruit and deliver
Sharma et al, 2006). it to produce markets in urban centres. The fruit begin to
The fruit is an emerging tropical export crop produced in ripen in November and the peak ripening months are
about 90 countries in the world with a production of over December and January. From the end of January the yield
25.1 million tonnes (Durrani et al, 2012). The mango of the fruit decreases and at the end of February the
world market earns about 700 million dollars per year, mango season ends. Producers incur losses of the fruit at
and world production in 2007 and 2008 was superior to harvesting and distribution due to short shelf life of the
30 x 106 tons whose world export was approximately 11 fruit. To minimize the losses, it is important to find
million tons (FAO, 2009). Asia is the main producer with methods of preserving the fruit or produce pulp which
76.9% of the total world production, followed by can be preserved.
America with 13.38%, Africa with 9% and less than 1% The mango pulp can be preserved by aseptic packaging,
each for Europe and Oceania (Rathore et al., 2007). In quick freezing, canning, chemical means or a
terms of production by country, India accounts for almost combination of two or more of these methods (Moraes et
half of the world production, followed by China (3 al., 2010; Younis et al, 2011). The experiments done here
million tons), Pakistan (2.25 million tons), Mexico (1.5 were aimed at identifying the most suitable techniques for
million tons), and Thailand (1.35 million tons) (Gundurao preservation of mango pulp using available resources.
et al., 2011). Combinations of potassium sorbate, sodium
In Zimbabwe, the production of mango is mainly for metabisulphite, citric acid and heat treatment were used
consumption as fresh fruit. On average, Zimbabwe for preservation of the pulp of mango grown in
Pakistan Journal of Food Sciences (2012), Volume 22, Issue 4, Page(s): 191-196 191PAK. J. FOOD SCI., 22(4), 2012: 191-196
ISSN: 2226-5899
Chamanimani, Zimbabwe. Chemical preservatives district. The cooperative is made up of forty five women
suppress microbial proliferation, reduce enzyme activity who dedicated their time and effort to processing of the
and block browning reactions resulting in increase in local fruit into jam, juice and puree.
shelf life of the pulp and products made.
Collection of fruit and pulp extraction
MATERIALS AND METHODS
Study area Ripe mangoes of different varieties were brought by the
The study was conducted in Rusitu Valley area in community men and women to the factory.The fruits
Chimanimani. Chimanimani is a district located in the were washed with running tap water and then hand-
south eastern part of Zimbabwe in Manicaland Province. peeled. The peeled mangoes were passed through a
The district covers an area of 3 353 km2 and borders stainless steel pulping machine with 5mm mesh where
Chipinge, Mutare and Buhera (Chimanimani Business the juice was extracted from fresh fruit by pressing. The
Trust Report, 2007). Agriculture constitutes the major pulp was stored at room temperature of 25 to 30oC in 100
economic activity within Manicaland, while forestry and litre plastic containers with air-tight plastic lids.
tourism are other economic activities. Rusitu Valley is a Pulp preservation
growing area for a variety of fruits that include mangoes, Five hundred (500) millilitre samples of pulp were each
bananas, pine apples, lemons, oranges and avocardo pears treated with varying amounts of sodium metabisulphite
(Zimbabwe Opportunities Industrial Centre, 2008). The and potassium sorbate followed by heat treatment at 80-
research was carried out at a factory owned by Rusitu 900C for some of the samples as recorded in table
Valley Jam Canners Cooperative. The factory is located 1(FAO, 1997). One sample, C0 was not treated with
at Koppa Business Centre, Rusitu Valley in Chimanimani
Table 1: Treatment of mango pulp of fruit from Chimanimani in Zimbabwe
Sample Treatment
C0 Unpasteurized sample, no heat treatment.
C1 Pasteurized sample at 80-90oC.
S1 1000 ppm sodium metabisulphite, 500 ppm citric acid, no heat treatment
S2 1000 ppm sodium metabisulphite, 500 ppm citric acid, 1000ppm potassium sorbate, no heat treatment
S3 1000 ppm sodium metabisulphite, 500 ppm citric acid, 1000ppm potassium sorbate, pasteurization at 80- 900C
S4 1500 ppm sodium metabisulphite, 500 ppm citric acid, no heat treatment
S5 1000 ppm sodium metabisulphite, 500 ppm citric acid, pasteurization at 80- 900C
S6 1500 ppm sodium metabisulphite, 500 ppm citric acid, pasteurization at 80- 900C
Pakistan Journal of Food Sciences (2012), Volume 22, Issue 4, Page(s): 191-196 192PAK. J. FOOD SCI., 22(4), 2012: 191-196
ISSN: 2226-5899
Chemical preservatives or heat and was used as a control. potassium sorbate and citric acid had different pH values
Sample C1 was pasteurized, but had no chemical with sample S2 which was not pasteurized having a lower
preservatives added to it. Samples S1, S2, S3, S4, S5 and pH than sample S3 which had undergone heat treatment.
S6 were treated with chemical preservatives as outlined in As shown in table 2, the pH of each sample decreased
table1. After the treatments, subsequent measurement and with time.
observations made on the samples were made at room The initial pH values of the samples which ranged from
temperature over a period of 21 days. 4.22 to 4.24 were similar to previously measured values
Determination of total soluble solids ranging from 4.2 to 4.3 (Moraes et al., 2010). However,
Total soluble solids were measured using a hand the final pH of the pulp after 21 days was higher than 3.0
refractometer (Model ATAGO N-1α) and expressed in to 3.2 obtained in earlier studies (Moraes et al., 2010).
0
Brix (Rababah et al., 2011). The instrument was The differences may be attributed to differences in
calibrated using distilled water. reagents used for treating the samples in this experiment
Determination of pH and samples considered in previous studies. The pH of
The pH of the fruit pulp samples were determined using a the unpasteurized sample C0, with no preservatives added
pH meter (model WTW pH 340i 82362 Weilheim) at a changed from 3.92 to 2.66 within three days. The drop in
temperature of 20 to 25°C. The pH meter was calibrated pH may be a result of microbial degradation of nutrients
using pH 4.00 and 7.00 standard buffers. producing acids and alcohols. Similarly, the pH of the
Determination of colour and odour of pulp pasteurized sample C1 dropped from 3.92 to 2.75 after 4
Colour of the pulp was assessed by visual inspection days. The results are consistent with work done by other
while odour was evaluated by smelling. researchers where pH decreased with time (Khan et al.,
2012). Measurements of pH and other parameters for
RESULTS AND DISCUSSION
samples C0 and C1 were terminated after 3 and 4 days
pH respectively because the samples had grown moulds that
Samples S4 and S6 were treated with sodium caused spoilage. The low pH favoured the growth of
metabisulphite and citric acid. Sample S4 was not moulds.
pasteurized and had lower pH values than sample S6 An ANOVA test for time points variation for the mean
which was pasteurized. The unpasteurized sample S4 was pH was done at α = 0.05 and gave a p-value of 0.057,
likely to have a higher microbial load that fermented showing that the different times had mean pH of mango
sugars in the pulp to form alcohols and acids which pulp that were insignificantly different from each other.
lowered the pH. Samples S1 and S5 were treated with
An analysis of variance (ANOVA) was conducted and
sodium metabisulphite and citric acid. Sample S1 which
did not undergo heat treatment had a lower pH than showed a p-value of 0.009, indicating that the mean pH
sample S5 which was pasteurized may be due to higher for the different samples were significantly different from
microbial load fermenting sugars resulting in a medium each other. Least Significant Difference (LSD) was
of higher acidity as in sample S6. Similarly, samples S2 further used for pairwise comparisons of the mean pH for
and S3 which were treated with sodium metabisulphite, the
Table 2: Changes in pH of mango pulp of fruit from Chimanimani in Zimbabwe within three weeks of observation. C0 was an
unpasteurized sample without chemical preservatives. C1 was a pasteurized sample but without chemical preservatives. Samples
S1, S2, S3, S4, S5 and S6 had added chemical preservatives.
Time pH
(Days)
C0 C1 S1 S2 S3 S4 S5 S6
0 3.92 3.92 4.22 4.22 4.23 4.22 4.24 4.22
1 3.97 4.00 4.21 4.16 4.19 4.11 4.15 4.12
2 4.03 4.06 4.05 4.06 4.08 4.04 4.06 4.06
3 2.66 2.98 3.96 4.05 4.06 4.02 3.97 3.99
4 - 2.75 3.81 3.98 4.04 3.98 3.95 3.90
7 - - 3.87 3.95 4.03 3.95 3.93 3.84
14 - - 3.73 3.93 3.98 3.64 3.89 3.80
21 - - 3.60 3.81 3.94 3.52 3.84 3.73
Mean 3.65±0.57 3.54±0.56 3.93±0.21 4.02±0.12 4.07±0.09 3.94±0.22 4.00±0.13 3.96±0.16
Means of pH values are significantly different (p0.05) for means of pH
values for samples S1 to S6.
Pakistan Journal of Food Sciences (2012), Volume 22, Issue 4, Page(s): 191-196 193PAK. J. FOOD SCI., 22(4), 2012: 191-196
ISSN: 2226-5899
Table 3: Changes in total soluble solids content of mango pulp of fruit from Chimanimani in Zimbabwe within three weeks of
observation. C0 was an unpasteurized sample without chemical preservatives. C1 was a pasteurized sample but without chemical
preservatives. Samples S1, S2, S3, S4, S5 and S6 had added chemical preservatives.
Time Total soluble solids (oBrix)
(Days)
C0 C1 S1 S2 S3 S4 S5 S6
0 13.9 17.5 9.0 9.0 9.0 9.0 9.0 9.0
1 14.2 15.0 9.0 9.0 9.0 9.0 9.0 9.0
2 14.0 15.5 9.0 9.0 9.0 9.0 9.0 9.0
3 14.0 15.9 9.0 9.0 9.0 9.0 9.0 9.0
4 - 14.7 9.0 9.0 9.0 9.0 9.0 9.0
7 - - 8.8 9.0 9.0 8.8 8.9 9.0
14 - - 8.6 9.0 9.0 8.2 8.0 8.9
21 - - 7.8 9.0 9.0 8.0 8.0 8.6
Mean 14.0±0.1 15.7±1.0 8.8±0.4 9.0±0 9.0±0 8.8±0.4 8.7±0.4 8.9±0.1
Means of total soluble solids values are significantly different (p0.05) for means of
total soluble solids values for samples S1 to S6.
Hurdle technology advocates the deliberate combination
samples and it was observed that samples C0 and C1 were of existing and novel preservation techniques in order to
similar whilst sample S1 up to sample S6 were establish a series of preservative factors or hurdles that
also insignificantly different from each other. The any micoorganisms present should not be able to
differences may be attributed to the effect of the chemical overcome resulting in increased shelf life of the food
preservatives on the pulp samples. The similarities in the product (Leistner and Gorris, 1995). The total soluble
pH of the samples S1 to S6 may result from possible solids content of C0 and C1 were almost constant during
buffering action of the preservatives. the period of the study, but decreased towards the end in
Total soluble solids a way similar to previous findings (Hussain et al., 2003).
As shown in table 3, there was a marked decrease in total An analysis of variance (ANOVA) was carried out and
soluble solids of the unpasteurized pulp in sample S1. The gave a p-value of 0.371, showing that the different times
drop in soluble solids content may be caused by had mean oBrix values of the mango pulp that were
fermentation of sugars to alcohols and acids by
insignificantly different from each other. Further, an
microorganisms present such as yeasts. Sample S5 which
was treated with the same chemical preservatives as analysis of variance (ANOVA) was done to assess
sample S1 and pasteurized retained a higher content of samples variation of the mean oBrix, a p-value of less
soluble solids than sample S1. The results show the than 0.001 was obtained, indicating that the mean oBrix
additional effect of heat on stabilizing the sugar content values were significantly different for the different
in sample S5. The heat of pasteurization possibly killed samples. Least Significant Difference (LSD) was then
vegetative yeasts cells. There was no change in total used for pair wise comparisons of the mean oBrix values
soluble solids content of samples S2 and S3 during the
of the samples and it was observed that samples C0 and
period under review, possibly due to yeasts and moulds
killed by potassium sorbate and bacteria destroyed by C1 were significantly different from all other samples
sulphur dioxide. Results for sample S2 and S3 show that whilst sample S1 up to S6 were insignificantly different
by the time heat was applied to sample S3, from each other.
microorganisms causing fermentation of sugars had
already died due to action of chemical preservatives. Colour
Sample S4 had a higher drop in total soluble solids when
compared with sample S6. In sample S6, the combined In sample S6 which was heat treated, sulphur dioxide was
action of chemicals and pasteurization might have lost as sodium metabisulphite rapidly degraded leading to
reduced microbial load resulting in minimal loss of non-enzymatic browning reactions. Sulphur dioxide
soluble solids due to fermentation. Hence, sample S4 blocks enzymatic and non-enzymatic browning reactions
which did not undergo heat treatment had a higher loss of (Fenemma, 1996; Ding et al., 2002). In sample S4 which
soluble solids probably due to fermentation than sample was not pasteurized, the pulp remained yellow. The
S6. Sample S6 illustrates the Hurdle concept. Hurdle available sulphur dioxide prevented enzymatic and non-
technology is a term applied when foods are preserved by enzymatic browning reactions resulting in retention of the
a combination of processes (Durrani et al., 2012; Moraes yellow colour by
et al., 2010). Examples of hurdles are temperature, water
activity, atmospheric conditions and preservatives.
Pakistan Journal of Food Sciences (2012), Volume 22, Issue 4, Page(s): 191-196 194PAK. J. FOOD SCI., 22(4), 2012: 191-196
ISSN: 2226-5899
Table 4: Changes in colour of mango pulp of fruit from Chimanimani in Zimbabwe within three weeks of observation. C0 was an
unpasteurized sample without chemical preservatives. C1 was a pasteurized sample but without chemical preservatives. Samples
S1, S2, S3, S4, S5 and S6 had added chemical preservatives
Time Colour
(Days)
C0 C1 S1 S2 S3 S4 S5 S6
0 Bright Bright Dark Dark Brownish Dark Brownish Brownish
yellow yellow yellow yellow yellow yellow yellow yellow
1 yellow Pale Dark Dark Brownish Dark Brownish Brownish
yellow yellow yellow yellow yellow yellow yellow
2 Dark Pale Dark Dark Brownish Dark Brownish Brownish
yellow yellow yellow yellow yellow yellow yellow yellow
3 Yellow Pale Dark Dark Brownish Dark Brownish Brownish
/mould yellow yellow yellow Yellow yellow yellow yellow
growth
4 - Yellow Dark Dark Brownish Dark Brownish Brownish
yellow yellow yellow yellow yellow yellow
/mould
growth
7 - - Dark Pale Brownish Pale Brownish Brownish
yellow yellow yellow yellow yellow yellow
14 - - Pale Pale Brownish Pale Brownish Brownish
yellow yellow yellow yellow yellow yellow
21 - - Pale Pale Brownish Pale Brownish Brownish
yellow yellow yellow yellow yellow yellow
Table 5: Changes in odours of mango pulp of fruit from Chimanimani in Zimbabwe within three weeks of observation. C0 was an
unpasteurized sample without chemical preservatives. C1 was a pasteurized sample but without chemical preservatives. Samples
S1, S2, S3, S4, S5 and S6 had added chemical preservatives.
Time Odor
(Days)
C0 C1 S1 S2 S3 S4 S5 S6
0 Fresh Fresh Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango mango mango
1 Strong Fresh Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango mango mango
2 stale Fresh Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango mango mango
3 stale Fresh Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango mango mango
4 - Stale Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango mango
7 - - Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango
14 - - Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango
21 - - Pungent Pungent Cooked Pungent Cooked Cooked
mango mango mango mango mango mango
the pulp. Observations made on colour of the pulp reactions between sugars and proteins. Sample S1 which
samples are recorded in table 4. was not heat treated was yellow, may be due to sulphur
Sample S5 lost sulphur dioxide due to pasteurization dioxide which blocked browning reactions. Similarly as
resulting in brown colour of pulp, possibly due to for samples S5 and S6, sample S3 which was also heat
caramelization reactions of sugars or Maillard browning treated turned brown, while sample S2 which was not
Pakistan Journal of Food Sciences (2012), Volume 22, Issue 4, Page(s): 191-196 195PAK. J. FOOD SCI., 22(4), 2012: 191-196
ISSN: 2226-5899
pasteurized remained yellow throughout the study period. preservatives which aid in prolonging the shelf life of the
There was no remarkable change in the colour of pulp for pulp by suppressing microbial proliferation.
samples C0 and C1. However, the samples had grown
CONCLUSION
moulds by the end of 4 days due to the absence of
chemical preservatives. In contrast to samples C0 and C1, From the results of the experiments performed, it was
no mould growths were observed in samples S1 to S6 found that the use of sodium metabisulphite, citric acid,
where chemical preservatives were added. potassium sorbate and pasteurization increased the shelf
Odour life and stabilized the sensory properties of the pulp. Heat
Samples S3, S5 and S6 which were pasteurized had a treatment inactivated enzymes that catalyze browning and
cooked mango odour while samples S1, S2 and S4 which fermentation reactions leading to pulp spoilage. The
were not heat treated had a pungent mango smell (Table addition of sodium metabisulphite, citric acid and
5). The pungent odour of unpasteurized pulp may be potassium sorbate was effective in preventing spoilage of
attributed to excess sulphur dioxide liberated in the the pulp. The Hurdle concept, which involves use of two
samples. The heat treated samples produced an odour that or more preservation methods, provides an optimum
was less offensive than unpasteurized samples. The procedure for preventing pulp spoilage and was
possible cause of the difference is loss of irritating illustrated in preservation of mango pulp in this study.
sulphur dioxide and volatile products of fermentation
from pasteurized pulp samples. The odours of samples C0 ACKNOWLEDGEMENTS
and C1 were those of fresh mango at the beginning, but The authors would like to appreciate the assistance
turned stale at the end of 3 and 4 days respectively. provided by Chimanimani Business Trust who provided
Products of putrefaction and fermentation were smelled at the facilities for the project and the University of
the end of the 3 to 4 day period. The spoilage was caused Zimbabwe for funding the study.
by microbial growth resulting from lack of chemical
sensory evaluation of mango pulp storage with chemical
REFERENCES preservatives. J. Res. (Science), 14 (1): 01-09.
1. Ding, C. K., K. Chachin, Y. Ueda and C. Y.Wang. 2002. 10. Khan R.U., S. R. Afridi, M. Ilyas, H. Abid, M. Sohail and
Inhibition of loquat enzymatic browning by sulfhydryl S. A. Khan. 2012. Effect of different chemical
compounds. Food Chem. 76: 213–218. preservatives on the storage stability of mango-sea
2. Chimanimani Business Trust Report. 2007. Business One- buckthorn blended juice. Pak. J. Biochem. Mol. Biol.
Stop Shop Capacity Building, Entrepreneurship Training, 45(1): 6-10.
Business Development and Support, and Access to 11. Leistner, L and L. G.M. Gorris. 1995. Food preservation
Information and Appropriate Technologies to the Informal by hurdle technology. Trends in Food Sci. & Technol. 6:
Sector Operators residing in rural communities, 41-45.
Chimanimani Business Trust.pp1-5. 12. Moraes, I.C.F., R.M. Sampaio, N.M. Queiroz, S.M. De
3. Durrani, Y., A. Zeb, Y.Xingqian, M. Ayub, W.Tahir, A. Salles, C.C. Pashoaleti and V.H. Parez. 2010. Mango Pulp
Muhammad and S.Wahab. 2012. Influence of storage (Mangifera Indica L.) Preserved by Hurdle technology:
temperatures on physicochemical sensory and nutritional Physicochemical, microbiological and rheological
properties of chemically preserved mango pulp. Afric. J. characterization. J. Food Proc. and Preserv. 35: 610-614.
Biotech. 11(13): 3147-3152. 13. Rababah T.M., M. H. Al-u’datt, M. A. Al-Mahasneh, H.
4. FAO. 2010. CCP: BA/TF 09/CRS 2 – Joint meeting of the Feng, A. M. Alothman, A. Almajwal, W. Yang, I. Kilani,
fourth session of the sub-group on bananas and the fifth M. N. Alhamad, K. Ereifej and M. Abu-Darwish. 2011.
session of the sub-group on tropical fruits. Tropical fruits Effect of storage on the physicochemical properties, total
compendium. December 7, 2010. phenolic, anthocyanin, and antioxidant capacity of
5. FAO. 1997. Guidelines for small-scale fruit and vegetable strawberry jam. J. Food, Agric. & Env. 9 (2): 1 0 1 - 1 0 5.
processors, FAO Corporate Repository, 14. Rathore, H.A., T. Masud, S. Sammi and A. H. Soomro.
http://www.fao.org/docrep/W6864E/W6864E00.htm: 2007. Effect of Storage on Physico-Chemical Composition
accessed: 21/08/2012. and Sensory Properties of Mango (Mangifera indica
6. Fennema O.R. 1996. Food Chemistry. 3rd Ed. Marcel L.)Variety Dosehari. Pak. J. Nutr. 6 (2): 143-148.
Dekker, New York, USA, pp783-785. 15. Sharma G.P., M. Dak and R.C Verma. 2006. Flow
7. Government of Zimbabwe. 2012. Second Round Crop and characteristics of juice of ‘‘Totapuri’’ mangoes. J. Food
Livestock Assessment Report, Ministry of Agriculture, Eng.76:557–561.
Mechanization and Irrigation Development.pp4-6. 16. Younis, M.S., M. S. Butt, M. K. Sharif, H. A. R. Sulerai
8. Gundurao, A., H.S. Ramaswamy and J. Ahmed. 2011. and F. Hameed. 2011. Effect of preservatives on
Effect of soluble solids concentration and temperature on physicochemical, microbial and sensory attributes of
the thermo-physical and rheological properties of mango mangoes, Internet J. Food Safety, 13:246-263.
puree. Int. J. Food Prop. 14:1018–1036. 17. Zimbabwe Opportunities Industrialization Centres (ZOIC).
9. Hussain, S. S. Rehman, M. A. Randhawa and M. Iqbal. 2008. Nurturing Sound Business Practices: Lessons from
2003. Studies on physic-chemical, microbiological and Chimanimani Business Trust Model, ZOIC.pp 1-10
Pakistan Journal of Food Sciences (2012), Volume 22, Issue 4, Page(s): 191-196 196You can also read
