Assessment of physico-chemical and phyto-chemical properties of six apple varities cultivated in district Nagar and Hunza Gilgit Baltistan, Pakistan

This research work was carried out to evaluate the physico-chemical properties of six apple varieties commonly found in the local market of district Nagar and Hunza Gilgit, Pakistan. Different chemical and phytochemicals parameters such as moisture content, ash content, total soluble solids, pH value, acidity, total sugar, reducing sugar, non-reducing sugar, antioxidant activity and total phenolic contents were studied. Results revealed that highest moisture content was observed in Golden Delicious Hard (84.96%) while lowest moisture content was observed in Red Delicious (78.19%). Maximum ash content was found in Golden Delicious (2.92%) while minimum ash content was observed in Spartan (0.35%). Similarly, maximum mean value for total soluble solids were noted in Golden delicious (13.00) while minimum mean value was noted in Kala Kulu (10.56). Highest acidity was found in Golden Delicious (0.26%) whereas lowest acidity value was noticed in FS (0.16%). Maximum mean values for pH were recorded in Spartan (3.89) whereas minimum value was observed in Noor Shah (3.50). Total sugars content in apple varieties ranged from 66.78 to 73.66%. Maximum mean value for reducing sugars was noted in Noor Shah (14.54) while minimum value was recorded in Spartan (10.64). Non reducing sugar in apple varieties ranged from 51.54 to 54.00%. Highest antioxidant activity was recorded in Noor Shah (15.12%) while lowest value was observed in Spartan (18.61%). Total phenolic contents were ranged from 151.27 to 203.03 GAE/100mg. On the bases of physico-chemical properties it was concluded that red delicious variety is the best cultivar as compared to other varieties grown in this region.

products which include jam, juices, puree, vinegar, jelly, frozen slices, canned slices and nectars [2]. Apple has good qualities it has to correspond to meet requirements of consumers and give satisfaction, needs, preferences, taste and habits [3]. Apple is one of the most important fruit species grown almost all over the world. According to the USDA, world total production of apples was 83.1 million tons. China is the topmost producer of apple producing 44 million tons annually which is 50% of world total production (USDA, 2018). According to the Pakistan Bureau of Statistics (2012/13); apples were produced over an area of 110,000 hectares with a total production of 556,000 metric tons, placing Pakistan on 11 th position among the top 25 producers in the world. Apple has great nutritional value and contains many nutrients including vitamin C, potassium and fiber. It also contains essential food constituents such as sugar (11%), proteins (0.3%), nearly 14% of apple is made up of carbohydrates, 4% minerals and remaining part contains 80% of water [4]. Different research revealed that apple fruit contained sufficient minerals that include Ca, K, Mg, Na, P and Zn. The Ca levels of apple fruits ranged between 7215.2 mg/kg to 10116.2 mg/kg [5]. Apple fruit has many health benefits which help in the maintenance of healthy life. The health benefits are associated with prevention from cancer, cardiovascular diseases, asthma, diabetes, Alzheimer's and diabetes. Red delicious apple has strong antioxidant activity, it contain quercetin which help in strengthen immune system of human body [6]. It was reported that apple have strong nutraceutical properties, so it was considered as defined functional food [7]. Apples are generally considered as the "sweet gold" of Pakistan and are among the most popular fruits. In Pakistan, it is grown as a commercial crop in Punjab, Khyber Pakhtunkhwa, Quetta and Gilgit Baltistan (GB) [8]. In Nagar and Hunza are famous for producing good quality apples.
According to the Statistics Department of GB; apple cultivation area is about 3 thousand hectares where annually production is about 10 thousand metric tons. Apple is one of the commonly grown cash crops in Gilgit-Baltistan [9] and has a significantly impact on income generation of poor people of mountain communities [10]. It is fourth important cash crop in the world after grapes, citrus fruits and banana [11]. Nagar and Hunza are blessed with many natural resources including fruits among which apple is the most famous. In Nagar and Hunza districts; different apple varieties are grown which include Red delicious (RD), Golden delicious (GD), Golden delicious hard, Kala kulu, Spartan and Noor shah. Different apple varieties are found in this area but due to lack of interest and awareness some varieties of apple are near to extinction and their chemical composition are still not explored [12]. The main purpose of this research work was to evaluated physico-chemical characterization of six apple varieties usually grown in Hunza Nagar to identify the best apple cultivar among six apple varieties on the basis of physical and chemical properties. Present study helped to explore the nutritional and phytochemical composition of different apple varieties grown in Hunza Nagar district.

Length (L)
Lengths of fruits were determined by digital caliper (0-150 mm, China) with an accuracy of 0.001 mm.

Width (W)
Widths of all apple verities were measured by digital caliper (0-150 mm, China) with an accuracy of 0.001 mm.

Thickness (T)
Thicknesses of fruits were measured by digital caliper (0-150 mm, China) with an accuracy of 0.001 mm. Volume (V) Volume of apple samples was measured by the liquid displacement method. Take a measuring jar and filled with water, note the level of water. Put an apple in measuring jar and record the level of water after putting apple in jar. The final volume of apple was calculated by using formula [16]. Volume =Final reading-Initial reading Diameter The Geometric mean diameter (Dg) was calculate by using given equation Dg = (L+W+T) 0.333 Where L is length, W is width and T is thickness of the fruit [17]. Surface area (S) Surface area of different apple varieties were determined according to method of Mosheim [17] by using following formula: S = πDg 2 Where Dg is the Geometric mean diameter of the fruit.

Statistical analysis
The data was analyzed and interpreted by using analysis of variance technique, comparison of means and other relevant statistical tools [18]. Results and discussion Different laboratory test were carried out determined the physico-chemical composition of all six apple varieties taken from study area. Chemical parameters involved; moisture contents, ash contents, total soluble solids, ph, titratable acidity total sugars, reducing sugars and nonreducing sugars. phytochemical experiments involved antioxidant activity and total phenolics contents. physical parameters; weight, length, width, thickness, volume, diameter and surface area. The data is recorded in (Table 1 to 5) and statistically interpreted by 1 way ANOVA using statistical software (Minitab and SPSS). The results were discussed as follow.

Chemical parameters Moisture content (%)
The moisture content of fruits and vegetable is an important indicator for determining the keeping quality and also an important sign of freshness of any food commodity. The moisture content of different apple varieties ranged from 78% to 88%, (Table 1). Highest moisture content was observed in Noor Shah that contained 87.55% while the lowest moisture content was recorded in Red Delicious apple variety that was 78.19% as shown in (Table 1) [26] suggested that total soluble solids contents in different apple verities grown in world ranging from 8.5° to 17° respectively. Our research outcomes showed conformance with previous studied.

Total Sugars (%)
Apples are rich source of sugars (reducing and non-reducing). The sugar profile is a significant constituent of chemical composition and provides important information concerning the authenticity of fruit juices. The analysis of variance for total sugars of apple varieties is given in Appendix VI. The statistical result revealed that the total sugars were differ significantly (P<0.05) among all verities. The mean value of total sugar level of six apple cultivars was in between 64.73% and 73.66% which were presented in (    (Table 4). It was suggaested that width of different apple varities ranged from 50mm to 110mm Kheiralipour et al. [21]. Current findings were interacted with early studied.

Thickness (mm)
The result showed that reading was recorded in different varities were ranging from 53 mm to 72 mm. The maximum thickness was recorded as 71.33mm in Red Delicious variety while the minimum thickness reported as 52.70mm in Spartan variety as mentioned in (Table 4). This studied was linked with the work of Kheiralipour et al. [21] who investigated that thickness of apple fruit ranged from 55mm to 95mm. Results are statistically significant (p<0.05).

Volume (mm)
Volumes and projected area of fruits must be known for accurate modeling of heat and mass transfer during cooling, drying, transporting, packing and storing. The mean values for fruit volume has been presented in (

Diameter (mm)
The mean values for fruit diameter have been presented in (  (Table 5). This study was also correlated with the previous work of Kheiralipour et al. [21] who early worked of some physical properties two different verities. The values are means of three replications with standard deviation (SD)

Conclusion
The results of current research work revealed that apple varieties cultivated in Nagar and Hunza valleys have rich nutritional and phytochemical components such as total sugar, ash contents, antioxidant activity, and total phenolics. On the basis of physico-chemical properties it was concluded that Red Delicious variety is the best cultivar as compared to other varieties grown in this region. The current study provides first hand physico-chemical information of six apple cultivars that will be supportive for the researchers and growers in developing