Research Article

Effect of Different Chemical Preservatives on the Quality Attributes of Guava Aloe vera Blended Pulp at Ambient Conditions

Rehman Ullah Khan* and Muhammad Ayub

Department of Food Science and Technology, Faculty of Nutrition Sciences, The University of Agriculture, Peshawar, Khyber Pakhtunkhwa, Pakistan

Received | March 18, 2020; Accepted | April 07, 2020; Published | April 20, 2020

*Correspondence | Rehman Ullah Khan, Department of Food Science and Technology, Faculty of Nutrition Sciences, The University of Agriculture, Peshawar, Khyber Pakhtunkhwa, Pakistan; Email: Rehmanullahfst@yahoo.com

Citation | Khan, R.U. and M. Ayub. 2020. Effect of different chemical preservatives on the quality attributes of guava aloe vera blended pulp at ambient conditions. Sarhad Journal of Agriculture, 36(2): 411-418.

DOI | http://dx.doi.org/10.17582/journal.sja/2020/36.2.411.418

Keywords | (GABP) Guava aloe vera blended pulp, Physico-chemical, S.B (sodium benzoate), K.M.S (Potassium metabisulphite) and P.S (potassium sorbate)

Introduction

Guava (Psidium guajava) is one of the most glorious and nutritionally valuable fruit. Guava fruit made of 20% peel, 50% flesh and 30% seed core, Wilson (1980). It is famous owing to its low price, nutritional significance and pleasant aroma along with taste. It is grown on an area of sixty two thousand hectare giving total annual production of five hundred and twelve thousand tons and eight thousand two hundred and twenty three kilogram per hectare yield Hassan et al. (2012). Guava is a rich source of ascorbic acid, carbohydrates, proteins, minerals, pectin, calcium and phosphorus (Garget and Ruggoo, 2007). Guava is mainly utilized in fresh as a dessert fruit due to wonderful aroma, good nutritive profile and cheap availability in excess quantity during its peak season reflects high potential for processing into products, having both nutritional and health benefits. It’s a best way for further utilization to prepare number of products from it like guava beverages, dehydrated products, jam and blended products with other fruits. The best way to reduce the post harvest losses is processing of surplus guava fruits into different products Bons et al. (2013).

Aloe vera plant has superb therapeutic uses. It is reported to be used in curing of diarrhoea, immune system regulation, tumors inhibition, liver protection, prevention of stomach from injury and repairing inner damage tissues etc. Aloe vera has diverse market potential Zhi et al. (2008). Leaves of aloe vera are rich source of vitamins, minerals, carbohydrates and amino acids. Human health is maintained by these aforementioned aloe vera leave constituents, Surjushe et al. (2008). Utilization of aloe vera pulp in food products has globally emerged a huge industry of functional food. Comparatively the functional products are rich source of biologically active compounds, Ramachandra et al. (2008). The blended beverage product may be a substitute refreshing nutritive drink and good source of bioactive compounds, vitamins and minerals, Sarkar and Jimmy (2017). The guava fruit and aloe vera contains important bioactive compounds and minerals. The preservation of guava aloe vera blended pulp will be helpful in minimizing the surplus yield and will fulfill requirements of functional food industry.

Materials and Methods

Procurement of raw materials and samples preparation

Optimum matured guava fruits (Kohat variety) were procured locally. After sorting, the guava fruits were thoroughly washed, the Pulp was obtained by using pulper machine. Fully expanded, mature, healthy and fresh leaves of aloe vera were picked from aloe vera orchard in PCSIR Peshawar. After washing, the outer skin of leaves was removed using sharp stainless steel knife and the obtained inner gel was blended in blender machine to obtain its pulp. The guava and aloe vera pulp was mixed in different proportions (90:10, 80:20, 70:30, 60:40 and 50:50) and sensory evaluation was conducted for selection of best suitable blend. The maximum score of judges was secured by (70:30) blend of guava and aloe vera pulp.

Plan of study

The treatments were prepared as GABP0 (control), GABP1 (0.1% Potassium Sorbate), GABP2 (0.1% potassium metabisulphite), GABP3 (0.1% sodium benzoate), GABP4 (0.05% each potassium sorbate and potassium metabisulphite), GABP5 (0.05% each potassium sorbate and sodium benzoate), GABP6 (0.05% each sodium benzoate and potassium meta bisulphite), GABP7 (0.033% each potassium sorbate, sodium benzoate and potassium metabisulphite).

Packaging and storage

The treatments of guava aloe vera blended pulp samples of all treatments were packed in 300ml pet bottles and stored at ambient conditions for six months.

Physico-chemical and sensory evaluation

The samples of guava and aloe vera blended pulp were evaluated for physico-chemical analysis including pH, percent acidity, total solids, complete sugar profile and ascorbic acid by the methods of AOAC (2012). Phenolic contents were determined by the spectrophotometric method of Sadasivam and Manicam (2008). The total antioxidant capacity was calculated by radical scavenging influence on the DPPH free radical by Goupy et al. (1999) and sensory evaluation including color, flavor and overall acceptability by nine points hedonic scale (Larmond, 1977). Analysis of the blended pulp samples were conducted after each month during six months study.

Statistical analysis

The data was analyzed statistically by using two fatorial Complete Randomized Design (CRD), and LSD test was employed for means separation at 0.05% significant level by (Steel and Torrie, 1997).

Results and Discussion

pH and titeratable acidity

The data of pH revealed decrease in all guava aloe vera blended pulp samples at ambient conditions. Mean value of pH at ambient temperature decreased from 4.51 to 3.47 during six months. The decrease in pH of treatments were as sample GABP0 from (4.50 to 1.28), GABP1 (4.51 to 3.72), GABP2 (4.52 to 3.84), GABP3 (4.50 to 3.80), GABP4 4.52 to 3.73, GABP5 ­4.51 to 3.83, GABP6 (4.50 to 3.78) and GABP7 (4.51 to 3.75) respectively. The highest mean value for treatment was noted for sample GABP2 4.26 chased by GABP6 4.21 while the sample GABP0 gives minimum mean value 2.79 followed by GABP1 4.12 (Figure 1). All values for pH of guava aloe vera blended pulp were significantly different at (p< 0.05). The increment in acidity of preserved guava pulp during storage period was due to organic acids generation. Break down of pectin and development of free radical might be associated for this decline in pH, Bal et al. (2014). Present study was in line with Ahmad et al. (2000), who observed that decrease in pH of guava pulp during storage.

The titratable acidity of guava aloe vara blended pulp samples was enhanced. The acidity of sample GABP0 was increased from 0.62 to 2.14, GABP1 0.61 to 0.98, GABP2 0.62 to 0.99, GABP3 0.62 to 0.95, GABP4 0.62 to 0.93, GABP5 0.62 to 0.95, GABP6 0.63 to 0.97 and GABP7 increased from 0.61 to 0.94. The highest increase in mean value was leaded by sample GABP0 1.31 chased by GABP1 0.81. The least mean was recorded by sample GABP4 0.76 succeeded by GABP2 0.77 (Figure 2). All values for titratable acidity of guava aloe vera blended pulp were significantly different at (p< 0.05). These finding is supported by Kinh et al. (2001), who noted increase in acidity of apple pulp. The outcomes of also confirm our results who claimed enhancement in acidity and decline in pH of apricot pulp during storage.

Total soluble solids of guava aloe vera blended pulp samples were raised at ambient temperature from 5.05 to 6.21. The total soluble solids of control sample was reduced from GABP0 (5.05 to 1.07) while increase was observed in GABP1 (5.04 to 6.45), GABP2 (5.05 to 6.94), GABP3 (5.05 to 7.08), GABP4 (5.06 to 7.06), GABP5 (5.05 to 6.98), GABP6 (5.02 to 6.95) and GABP7 (5.04 to 7.14) during 180 days study (Figure 3). Lead in treatments means was attained by GABP6 (6.16) runner up by GABP6 (6.08) whereas the lowest mean value was acquired by treatment GABP0 (3.33) followed by GABP1 (5.74). All values for total soluble solids of guava aloe vera blended pulp were significantly different (p< 0.05). The finding of Suman et al. (2017) support our data, who stated that total soluble solids of stored guava pulp was increased with the advancement in storage. The increment in TSS content of preserved guava pulp during storage was probably due to conversion of free polysaccharides (starch) into monosaccharide Jain et al. (2007). Another study of Kumar et al. (2015), also confirmed our results as they stated increase trend in total soluble solids during storage.

At room temperature the reducing sugars of guava aloe vera blended pulp samples were enhanced from 3.54 to 3.73 during six months of storage period. Reducing sugar of sample GABP1 was increases from (3.52 to 4.02), GABP2 (3.55 to 4.03), GABP3 (3.53 to 4.08), GABP4 (3.54 to 4.16), GABP5 (3.55 to 4.18), GABP6 (3.53 to 4.12) and GABP7 (3.54 to 4.19) during shelf life of 180 days studies respectively (Figure 4). The lead in mean value was attained by the sample GABP7 (3.91) followed by GABP5 (3.87) whereas the lowest mean value was retained by GABP0 (2.06) succeeded by GABP2 (3.76). All values for reducing sugars of guava aloe vera blended pulp were significantly different at (p< 0.05). Desai et al. (2012) stated the similar results, who claimed increase in reducing sugar mango pulp. Suman et al. (2017) also lay down similar increase in sugar profile. Complex carbohydrates like hemicelluloses and other saccharides into simple soluble sugars might be responsible for this change.

The guava aloe vera blended pulp samples showed decrease in non-reducing sugars at room temperature GABP0 from (1.47 to 1.0), GABP1 (1.48 to 0.98), GABP2 (0.81 to 0.97), GABP3 (1.47 to 0.92), GABP4 (1.46 to 0.84), GABP5 (1.45 to 0.82), GABP6 (1.47 to 0.88) and GABP7 (1.46 to 0.81) respectively during 180 days of its shelf life studies (Figure 5). The highest mean was acquired by GABP2 (1.24) followed by GABP1 (1.19) whereas the least value was retained by sample GABP0 (0.85) succeeded by GABP7 (1.10). All values for non-reducing sugars of guava aloe vera blended pulp were significantly different at (p< 0.05). Findings of Durrani et al. (2016) are in line with our data, who find decrease in non reducing sugar of mango pulp which is associated with degradation of complex sugars and formation of simple carbohydrates. Reddy et al. (2006) and Tefera et al. (2008) also revealed changes in sugar profile.

The guava aloe vera pulp samples showed decline in ascorbic acid content during six months storage stability studies at ambient temperature. The ascorbic acid was reduced from 120.42 to 51.48mg/ 100gm. During stability studies of guava aloe vera pulp samples for six months, the ascorbic acid was reduced as GABP0 from (121.80 to 2.17), GABP1 (120.41 to 60.84), GABP2 (120.20 to 58.95), GABP3 (120.20 to 65.48), GABP4 (120.20 to 56.85), GABP5 (120.15 to 55.79), GABP6 (120.08 to 53.89) and GABP7 (120.04 to 57.78) (Figure 6). The treatment GABP3achieved highest mean value (93.66) followed by GABP1 (88.22) while sample GABP0 retained the lowest value (46.38) succeeded by GABP6 (85.51). All values for ascorbic acid of guava aloe vera blended pulp were significantly different at (p< 0.05). Yadve et al. (2017) claimed decrease in ascorbic acid of guava pulp. Decline was occurred by degradation of ascorbic acid by enzymes. The findings of Bons et al. (2011) also assured our data of ascorbic acid.

Guava aloe vera blended pulp samples responded decrease in total phenolic compounds (mg gallic acid equivalents/100g) at ambient temperature during storage of six months. The total phenolic compounds were reduced from 32.43 to 11.47 mg gallic acid equivalents/100g. The treatments showed the decrease as GABP0 from (32.20 to 2.31), GABP1 (32.15 to 13.36), GABP2 (32.68 to 12.47), GABP3 (32.82 to 14.42), GABP4 (32.36 to 11.59), GABP5 (32.57 to 12.14), GABP6 (32.43 to 13.05) and GABP7 (32.19 to 12.38) (Figure 7). Maximum mean value for treatment was revealed by GABP7 (24.51) followed by GABP6 (23.21) while GABP0 retained minimum mean value (16.89) followed by GABP1 (20.07). All values for total phenolic compound of guava aloe vera blended pulp were significantly different at (p< 0.05). The present reduction of phenolic compounds are in accordance with Cansino et al. (2013) and Kapoor and Ranote (2016) who reported significant decline in

phenolic content during storage period. phenolic compounds are volatile in nature, which were reduced in storage, (Ranganna, 1986).

Antioxidant capacity

All samples of guava aloe vera blended pulp showed decrease in antioxidant at storage of ambient conditions. Mean value was decreased from 32.08 to 19.14 during period of six months. The decrease in treatments was GABP0 from (75.50 to 6.52), GABP1 (76.23 to 31.52), GABP2 (75.76 to 35.11), GABP3 (75.41 to 37.74), GABP4 (76.14 to 33.05), GABP5 (76.06 to 42.21), GABP6 (75.89 to 39.41) and GABP7 (76.09 to 41.56) respectively (Figure 8). The sample GABP7 achieved highest mean value (60.44) followed by GABP6 (58.65) while sample GABP0 attained lowest mean value (33.05) chased by GABP1 (50.15). All values for antioxidant capacity of guava aloe vera blended pulp were significantly different at (p< 0.05). These finding are confirmed by Prabal et al. (2018) who documented significant reduction in antioxidant capacity during 60 days. These results are also in line with Hoffmann et al. (2017) who recorded fifty percent decline in antioxidant capacity in buti fruit pulp and nectar during storage.

Color: Sensory evaluation is an important aspect for the analyzing the quality of food products. The mean score for color of guava aloe vera blended nectar was decreased from 9.00 to 5.73. The reduction in treatments mean value for color was GABP0 from (9.00 to 1.00), GABP1 (9.00 to 4.46), GABP2 (9.00 to 7.37), GABP3 (9.00 to 5.52), GABP4 (9.00 to 5.85), GABP5 (9.00 to 6.21), GABP6 (9.00 to 6.63) and GABP7 (9.00 to 6.74) respectively. The sample GABP7 and GABP2 attained the maximum mean value (8.08) followed by GABP5 (8.02) while lowest mean was noted for GABP0 (3.94) chased by GABP1 (7.25) (Figure 9). All values for color of guava aloe vera blended pulp were significantly different at (p< 0.05). This decline in data was supported by Kumari (2016), who reported decline in color. Yadav et al. (2017) also claimed similar reduction in color of guava pulp.

Taste: The mean value for taste of guava aloe vera blended pulp samples at room temperature were decreased from 8.85 to 4.90. The decrease in mean value for treatments was recorded as GABP0 from (8.80 to 1.00), GABP1 (8.90 to 3.58), GABP2 (8.85 to 5.81), GABP3 (8.80 to 4.62), GABP4 (8.88 to 5.26), GABP5 (8.85 to 6.48), GABP6 (8.80 to 6.25) and GABP7 (8.85 to 6.13) respectively (Figure 10). Highest mean value was acquired by treatment GABP5 (7.74) followed by GABP6 (7.64) while the treatment GABP0 (3.36) chased by GABP1 (6.28). All values for taste of guava aloe vera blended pulp were significantly different at (p< 0.05). These findings were accordance with Rafia et al. (2018) who recorded decline trend in taste for guava ready to serve beverage. Another conclusion of Pandey (2004) also supported our results who found similar decreasing trend for taste in product of guava.

Overall acceptability: The overall acceptability of guava aloe vera blended pulp was reduced at ambient temperature from 8.96 to 5.06. The mean score for treatments were reduced GABP0 from (8.95 to 1.00), GABP1 (8.91 to 4.03), GABP2 (9.00 to 6.01), GABP3 (8.90 to 5.64), GABP4 (9.00 to 4.95), GABP5 (8.95 to 6.15), GABP6 (8.94 to 6.27) and GABP7 (9.00 to 6.35) respectively (Figure 11). The GABP7 attained the maximum mean score (7.87) chased by GABP6 (7.81) while minimum score was achieved by GABP0 (4.51) followed by GABP1 (7.18). All values for overall acceptability of guava aloe vera blended pulp were significantly different at (p< 0.05). Shahnawaz et al. (2012) stated similar decline in overall acceptability of mango sea buckthorn blended pulp during storage. Likewise, observations were recorded by Saeed et al. (2010). Khurshid and Zeb (2008) also reported the decrease in overall acceptability of low caloric apple drink during refrigerated storage.

Ahmad, I., R. Khan and A. Muhammad. 2000. Effect of added sugar at various concentrations on the storage stability of guava pulp. Sarhad J. Agric., 16(1): 89- 93.

AOAC, 2012. Official methods of analysis of the association of official analytical chemists, 19th ed., pp. 1058-1059.

Ayub, M., T. Durrani, A. Zeb and J. Ullah. 2007. Effect of sucrose and potassium metabisulphite on the physicochemical and microbial analysis of apricot pulp. Pak. J. Sci. Ind. Res. 50(4): 251-253

Bal, L.M., T. Ahmad, A.K. Senapati and P.S. Pandit. 2014. Evaluation of quality attribute during storage of guava nectar cv. Lalit from different pulp and TSS ratio. J. Food Proc. Technol., 5(5): 329-334.

Bons, P.D., D. Jansen, F., Mundel, C.C., Bauer, T., Binder and O. Eisen. 2011. Response of guava pulp during storage ambient conditions. Nature Commun. 7(1): 11-27

Bons, H.K. and S.S. Dhawan. 2013. Studies on preservation of guava pulp. Indian J. Hortic., 70(3): 452-454.

Cansino, N.C., G.P. Carrera, Q.Z. Rojas, L.D. Olivares, E.A. García and E.R. Moreno. 2013. Ultrasound processing on green cactus pear (Opuntia ficus Indica) juice: physical, microbiological and antioxidant properties. J. Food Process. Technol. 1: 4-9. 

Desai, C.S., A.K. Naik and J.M. Patil. 2012. Study on physiochemical properties of some early mango (Mangiferaindica L) varieties for pulp processing. Beverages Food World, 39(2): 55-57.

Durrani, Y., A. Zeb, S.A. Ali, N.U. Khan, J. Hussain, T.A. Naqvi and T. Ahmed. 2016. Effects of chemical preservatives on mango squash stored under different temperature regimes. Minerva Biotecnol., 28(3): 153-158.

Garget, D.G. and A. Ruggoo. 2007. Effect of processing and storage of guava into jam and juice on the ascorbic acid content. J. Plant Nutri. 58: 1-12.

Goupy, P., M. Hgues, P. Bovin and M.J. Amiot. 1999. Antioxidant composition and activity of barley (Hordeum vugare) and malt extracts of isolated phenolic compounds. J. Sci. Food Agric., 79: 1625-1634. https://doi.org/10.1002/(SICI)1097-0010(199909)79:12<1625::AID-JSFA411>3.0.CO;2-8

Hassan, I., W. Khurshid and K. Iqbal. 2012. Factors responsible for decline in guava (Psidium guajava) yield. J. Agric. Res., 50(1): 129-134.

Hoffmann, J.F., G.P. Zandona, P.S.D. Santos, C.M. Dallmann, F.B. Madruga, C.V. Rombaldi and F.C. Chaves. 2017. Stability of bioactive compounds in Butia (Butia Odorata) fruit pulp and nectar. Food Chem., 237: 638-644. https://doi.org/10.1016/j.foodchem.2017.05.154

Jain, P.K. and P.K. Nema. 2007. Processing of pulp of various cultivars of guava (Psidiumguajava L.) for leather production. Agric. Eng. Int. Int. Counc. Large Electr. Syst., 9: 1-9.

Kapoor, S. and P.S. Ranote. 2016. Antioxidant components and physico-chemical characteristics of jamun powder supplemented pear juice. J. Food Sci. Technol., 53(5): 2307–2316. https://doi.org/10.1007/s13197-016-2196-x

Kinh, S.A.E.H., C.P. Dunne and D.G. Hoover. 2001. Preparation and preservation of apple pulp with chemical preservatives and mild heat. J. Food Prot. 28(6): 111- 114

Khurshid, A. and A. Zeb. 2008. Preparation and quality analysis of low caloric apple drink. Thesis. Dept. Food Sci. Tech. Univ. Agric. Peshawar.

Kumar, M., R.K. Godara, D. Singh, D.V. Pathak and S. Singh. 2015. Effect of different preservatives on the storage of ber pulp. Int. J. Farm Sci., 5(4): 222- 228.

Kumari, Y. 2016. Studies on effect of blending impact of guava (Psidium guajava L) and papaya (Carica papaya L) pulp on recipe standardization of blended nectar and RTS (ready to serve) beverages. M. Sc. (Hort) thesis. Dept. Fruit Sci. Indira Gandhi Krishi Vishwavidyalaya Raipur.

Prabal, P.S., A.D. Tripathi, D.C. Rai, N. Kumar and U.P. Singh. 2018. To study the shelf life of Aloe vera fortified mango RTS with different time and temperature combinations on its organoleptic and functional properties. Pharm. Innov. J. 7(3): 91-97.

Rafia, R., A. Bhat, A. Dayal, M. Sood and S. Sharma. 2018. Studies on storage stability of guava RTS. Pharm. Innov. J. 7(5): 230-233.

Ramachandra, C.T. and P.S. Rao. 2008. Processing of aloe vera leaf gel. Rev. Am. J. Agric. Boil. Sci., 3(2): 502-510. https://doi.org/10.3844/ajabssp.2008.502.510

Ranganna, S., 1986. Handbook of analysis and quality control for fruit and vegetable products, 2nd edn. Tata McGraw Hills Publ Co. Ltd, New Delhi.

Reddy, L.V.A. and O.V.S. Reddy. 2006. Production and characterization of wine from mango fruit (Mangifera indica L). World J. Micro. Biotech. 21(13): 45-50.

Sadasivam, S. and A. Manickam. 2008. Biochemical methods, 3rd Edn, New Age Int. (P) Limited Publ., pp. 203-206.

Saeed A., M. Riaz, A. Ahmad and A. Nisar. 2010. Physico-chemical, microbiological and sensory stability of chemically preserved mango pulp. Pak. J. Bot. 42(2): 853-862

Sarkar, A. and B. Jimi. 2017. Standardization of blending of guava pulp with pineapple juice for preparation of Ready-To-Serve (RTS). Int. J. Curr. Microbiol. App. Sci., 6(11): 395-401. https://doi.org/10.20546/ijcmas.2017.611.045

Shahnawaz, M., A. Wali, Y. Durrani, M. Ayub, A. Muhammad, M.R. Khan and H. Khan. 2012. Refrigerated storage studies of mango seabucthorn blended pulp with selective chemical preservatives and ginger extract. Int. J. Food Nut. Sci., 1(1): 01-07.

Steel, R.G.D. and J.H. Torrie. 1997. Principles and procedures of statistics. McGraw Hill Book Co. New York. Stat. Proc. Agric. Res. (2nd Ed). pp. 8-22.

Surjushe, A., R. Vasani and D.G. Saple. 2008. Aloe vera: a short review., Indian J. Dermatol. 53(4): 163-166. https://doi.org/10.4103/0019-5154.44785

Suman, K.Y., D.K. Sarolia, S. Pilania, H.R. Meena and L.N. Mahawer. 2017. Studies on keeping quality of preserved guava pulp during storage. Int. J. Curr. Microbiol. App. Sci. 6(3): 1235-1242. https://doi.org/10.20546/ijcmas.2017.603.142

Tefera, A., T. Seyoum and K. Woldesadik. 2008. Effects of disinfection packaging and evaporatively cooled storage on sugar content of mango. Afr. J. Biotech. 7: 65-72.

Wilson, C.W., 1980. Tropical and Sub-tropical Fruits: composition, properties and uses. AVI Publ. Inc. West Port Connecticut, 25(2): 279-295.

Yadav, S.K., D.K. Sarolia, S. Pilania, H.R. Meena and L.N. Mahawer. 2017. Studies on keeping quality of preserved guava pulp during storage. 2017. Int. J. Curr. Microbiol. App. Sci. 6(3): 1235-1242. https://doi.org/10.20546/ijcmas.2017.603.142

Zhi, L., Z.J. Ling and Y.Z. Wen. 2008. Study of a compound juice made of aloe and apple. Fruit Proc. 18(6): 312-314.