Open Access Asian-Australas J Anim Sci Vol. 32, No. 10:1591-1602 October 2019 https://doi.org/10.5713/ajas.18.0750 pISSN 1011-2367 eISSN 1976-5517 Antioxidant potential of a soft cheese (paneer) supplemented with the extracts of date (Phoenix dactylifera L.) cultivars and its whey Tahir Mahmood Qureshi1, Aniqa Amjad2, Muhammad Nadeem2,*, Mian Anjum Murtaza2, and Masooma Munir3 * Corresponding Author: Muhammad Nadeem Objective: The present study was conducted to evaluate the antioxidant potential of paneer, Tel: +92-3344416131, Fax: +92-48-9230671, E-mail: [email protected] a soft cheese supplemented with various water soluble date extracts during storage. Further, the whey obtained from all the paneer samples was also investigated for its antioxidant 1 Department of Food Sciences, Cholistan University of potential. Veterinary & Animal Sciences, Bahawalpur, 63100, Pakistan Methods: The date cultivars were evaluated for their physico-chemical characteristics and 2 Institute of Food Science and Nutrition, University of date extracts were assessed for their antioxidant potential. Physico-chemical evaluation, Sargodha, Sargodha, 40100, Pakistan microbiological quality and further antioxidant potential of the prepared paneer were carried 3 Food Science Research Institute, National Agricultural Research Centre, Islamabad, 44000, Pakistan out during storage period (0 to 8 days, 5°C). Results: All the date extracts were found to have considerable antioxidant activity due to ORCID presence of total phenolics and flavonoids. Owing to the presence of phenolics and flavoinds Tahir Mahmood Qureshi https://orcid.org/0000-0002-1580-4533 in date extracts, supplemented paneer showed higher trolox equivalent antioxidant capacity, Aniqa Amjad reducing power and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than https://orcid.org/0000-0002-9854-0122 control paneer. Paneer supplemented with Rabi extracts had the highest total phenolics Muhammad Nadeem https://orcid.org/0000-0002-7066-4334 (190.7 μg gallic acid equivalent/g paneer), DPPH radical scavenging activity (928.1 μmol Mian Anjum Murtaza equivalent of Trolx/g paneer) and trolox equivalent antioxidant capacity (9.2 μmol equivalent https://orcid.org/0000-0002-0893-7397 of Trolx/g paneer). The whey obtained from control paneer showed lower values of total Masooma Munir phenolics, total flavonoids, DPPH, trolox equivalent antioxidant capacity and reducing power https://orcid.org/0000-0003-1895-7663 as compared to the values of whey obtained from paneer supplemented with date extracts. Submitted Oct 5, 2018; Revised Dec 24, 2018; Conclusion: Paneer supplemented with date extracts and its whey may offer potent anti- Accepted Feb 4, 2019 oxidant activity. Keywords: Date Cultivars Extracts; Paneer; Physico-chemical Characteristics; Microbiological Quality; Antioxidant Potential INTRODUCTION Paneer is a primitive soft cheese variety which is produced by heat treatment of milk fol- lowed by acid coagulation using some suitable acid viz. lactic acid, citric acid, tartaric acid, sour whey, alum. It is used in culinary dishes/snacks and sweets like rasgolla, rasmalai, sandesh etc. It is considered as an important nutritious and wholesome indigenous dairy product, which occupies a prominent place among other traditional milk products and carries market potential [1]. It is considered a rich source of high quality proteins, fat, minerals and vita- mins. Different studies concerning antioxidant activity of different cheeses such as cottage cheese [2], Parmigiano-Reggiano cheese [3], traditional Sheep cheese (Bieno Sirenje) [4] and Indian paneer supplemented with peel extracts from pomegranate, lemon and orange [5] have been conducted by many researchers. The date palm (Phoenix dactylifera L., family Arecaceae) fruit is commonly consumed in Middle East and around the world due to its nutritional, economic and medicinal prop- Copyright © 2019 by Asian-Australasian Journal of Animal Sciences This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and repro- www.ajas.info duction in any medium, provided the original work is properly cited. 1591 Qureshi et al (2019) Asian-Australas J Anim Sci 32:1591-1602 erties [6]. Antioxidant activity and phenolic contents of some and total protein were determined by the standard methods date fruit cultivars grown in Saudi Arabia, USA and Oman of the Association of Official Analytical Chemists (AOAC) have already been investigated [7-9]. [13]. The carbohydrate content was determined by subtract- To most of the people in our culture, paneer is considered ing the moisture, crude fiber, fat, total protein and ash content a tasteless dairy product. So the addition of date extract into from the total mass (i.e. 100). The estimated energy values the milk intended for paneer making would be a better option were calculated by summing the multiplied values for fat, to- to enhance the bioactivity and palatability. Different date cul- tal protein and carbohydrate by their respective factors (9, 4, tivars are available in the local market of Pakistan but the and 4). Before evaluating pH and acidity, the fruit flesh of each most commonly consumed cultivars99 selectedfruit flesh in the of presenteach date cultivardate (10 cultivar fruits) (10 was fruits) mashed was with mashed the help with of the a pestle help ofmortar a pestle to form a paste. The study were Aseel, Rabi, Irani, and Muzafati. To date, no com- mortar to form a paste. The pH of each date paste was deter- 100 pH of each date paste was determined by digital pH meter [13] and the total titratable acidity was determined prehensive study was conducted regarding physico-chemical mined by digital pH meter [13] and the total titratable acidity characteristics of selected indigenous101 dateb ycultivars titrating and 10 mLanti aliquot- ofwas sample determined (1:10 dilution) by titrating with 10 standardized mL aliquot 0.1 of Nsample NaOH (1:10 to an endpoint of pH oxidant activity of their water soluble date extracts (30°Brix). dilution) with standardized 0.1 N NaOH to an endpoint of pH It was decided to use water soluble102 date extracts8.1. Phenolphthalein as water sol- was used8.1. as Phenolphthalein an indicator and was the resultsused as were an indicator expressed and as thegrams results of citric acid/100 mL uble (hydrophilic) phenolics (mainly cinnamic acids) and were expressed as grams of citric acid/100 mL of sample [13]. flavonoids (flavones, flavonols,103 and flavanones)of sample [13 with]. Following appre- formulaFollowing was formula used to wascalculate used toacidity calculate of samples: acidity of samples: ciable free radical scavenging activity104 and antioxidant activity have been previously reported [10]. Acidity % Moreover, no literature was found concerning antioxi- 64 (MW) × 0.1N (NaOH) × Titer value (mL) 105 Acidity % = × 100 dant potential of paneer supplemented with date extracts. 1000 × 10 (aliquot taken) Therefore, in view of the above aspects, the present study was designed to study the physico-chemical106 characteristics Preparation of date extracts of date cultivars indigenous to Pakistan in a comprehensive All the date cultivars (Aseel, Rabi, Irani, and Muzafti) were manner and further, to evaluate 107the antioxidantPreparation potential of date of extractswashed thoroughly with tap water and then pitted and cut paneer supplemented with water 108soluble Alldate the extracts date cultivarsduring (Aseel,into Rabi, small Irani pieces., and TheyMuzafti) were were steamed wash ed(90°C thoroughly to 95°C with for tap10 water and then storage as well as whey collected from those paneer. Being min) to prevent growth of bacteria, mould and for inactiva- rich source of major and minor bioactive109 componentspitted and cut [11,12], into small pieces.tion They of any were enzyme steamed and (90to make°C to 95the° Cflesh for 10 soft. min) Mincingto prevent of growththe of bacteria, buffalo milk was used for paneer production. cut pieces was done by mincing machine, which converted 110 mould and for inactivation themof any into enzyme paste. and Then to make the pastethe flesh was soft.heated Mincing after ofaddition the cut of pieces was done water (1:1) at 60°C to 70ºC for 2 to 3 hours. The heated paste MATERIALS AND METHODS111 by mincing machine, which converted them into paste. Then the paste was heated after addition of water was then cooled and blended by using a blender. The slurry Chemicals 112 (1:1) at 60°C to 70ºC for 2 wasto 3 filtered hours. Thethrough heated a pastemuslin wascloth then to separate cooled andthe blendeddate extract by using a blender. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH), Catechin, Folin- from the fruit flesh. The brix of all extracts was maintained Ciocalteu reagent and Trolox were113 purchased The slurry from was Sigma- filtered throughat around a muslin 30°Brix cloth byto separatethe removal the datof emore extract moisture from the at fruit60°C flesh . The brix of Aldrich Chemical Co. (St. Louis, MO, USA). Sodium phosphate, to 70°C through water bath. The obtained extracts were saved 114 all extracts was maintained at around 30°Brix by the removal of more moisture at 60°C to 70°C through aluminium trichloride (AlCl3) and sodium carbonate were in bottles at refrigeration (4°C) and used the next day in mak- purchased from Daejung Co. Ltd., Korea. Calcium carbonate ing paneer. The date extracts were also centrifuged at 14,000 115 water bath. The obtained extracts were saved in bottles at refrigeration (4°C) and used the next day in was purchased from BDH Laboratory Supplies, England. g for 10 min in eppendorf centrifuge (Hermle Labortechnik All other chemicals were of analytical116 grade.making paneer. The date extractsGmbH wereSiemensstr-25 also centrifuged D-78564 at Wehingen, 14,000 g for Germany) 10 min atin 4°C.eppendorf centrifuge The clear supernatant was taken for carrying out antioxidant Milk and date fruit samples 117 (Hermle Labortechnik GmbHpotential. Siemensstr -25 D-78564 Wehingen, Germany) at 4°C.