Organoleptic Characteristics of Whey Treated by Cation Exchange Resin

A single column cation exchanger resin was used to eliminate cations from renet cheese whey, with particular reference to the improvement of taste and flavor. Ten panelists were convened to assess the contribution of the mineral components to the salty taste of whey, judging on the basis of taste, flavor and color. The organoleptic characteristics of untreated whey were arbitrarily assigned a score of zero and the best treated whey in terms of quality, a score of 20. The use of a strong-acid cation exchange resin resulted in the removal of 28% of the calcium and 45% of the magnesium from treated whey with a concomitant increase in the concentration of sodium. The average score of treated whey increased from zero, for untreated whey, to 19.7 for the first element of whey passed through cation exchange resin. Keyword: Whey, Cation exchange, Resin, Taste, Flavor. _____________________________________________________________________________ 1 Institute of Aboureyhan, University of Tehran. P.O.Box: 4117. Tehran, Islamic Republic of Iran. INTRODUCTION Whey is a serum or the watery part of milk that remains after separation of the curd resulting from the coagulation of milk by proteolytic enzymes. Whey, therefore, contains many of the nutrients present in milk that are useful for human consumption. However, the objectionable taste of whey has resulted in the disposal of this nutrient in the effluent from cheese-making factories. The use of cheese whey in both a pilot project and on an industrial scale was reviewed under the following headings: whey disposal, animal feed, dried whey, fermented whey, deproteinized whey, whey permeate, hydrolysed whey and lactose and lactose derivatives [8]. In 1992, Jelen [4] investigated the manufacture, composition, nutritional value and utilization of cheese whey as a beverage. Vasil’eva [14] and co-workers developed a cheese whey beverage by heating the whey, allowing it to stand, filtration, the addition of extract an of hawthorn or sweet briar in a proportion of 10-13% to the whey, mixing, pasteurization, cooling and decanting. The aforementioned extract was obtained by comminuting plant fruits to a particle size of 1.0 to 1.5mm before extraction, with clarified whey, in a ratio of 1:20-25. The extract was then mixed with 2-3% sugar [14]. In another study, three citric acid whey beverages were prepared using acid whey, deproteinated acid whey plus toned milk (in a ratio of 3:1) or acid whey plus toned milk (in a ratio of 3:1) [6]. In 1998, Barabas and Albrecht [1], also studied the production of three flavors of whey drink-orange, apple and lemon-with a 90% whey content in the final product. In order to lower the level of protein sedimentation, the production technology was modified by placing homogenization after pasteurization. Furthermore, Reddy and co-workers [13] made a whey beverage from deproteinized whey by the addtion of (i) 6% lemon juice and 11 % sugar, (ii) 8% lemon juice and 14% sugar or (iii) 0.3% lemon flavor and 9% sugar as well as the addition of coloring, heat treatment to 80 0C for 15 _______________________________________________________________ Safari and Shahnazari 114 minutes, filtering, bottling and sterilizing at 120 C for 10 minutes. This was followed by cooling and refrigeration (4-6C) ors storages at room temperature, (18-25C), for up to 15 days. In another study, Michell [7] prepared two tomato beverages which were fortified with whey protein concentrates (WPC) that had been manufactured by ultrafiltration. Patil et al. [12], in 1984 reviewed the manufacture of whey-soy beverages. In 1983, Nolan (9) prepared a chocolateflavored shake-type beverage containing 84% whey and 8% groundnuts at the University of Arizona, Tucson. The whey was untreated prior to use but the whole groundnunts along with their skins were soaked in sodium bicarbonate overnight to decrease the groundnut flavor before being incorporated into a whey slurry. Other ingredients used were 7%, sugar 1% cocoa and 0.05% emulsifier. The presence of lactose in whey provides the opportunity to develop fermented cheese whey. In one study, ginseng extract and sucrose were added to whey which had been fermented with lactic acid bacteria for four days and to a non-fermented (control) whey [11]. Sensory evaluation was carried out, and changes in composition were examined. The initial pH of the whey was 6.14, its acidity was 0.11%, the protein content 0.77 g%, Lactose 4.89g%, Lactic acid 8mg%, and ash 0.4 g%. Hoppes and Higgins [3] proposed various different techniques of demineralization including: ion exchange, electrodialysis, reverse osmosis and counter diffusion. Ion exchange, in its traditional form, is a fixedbed technique involving the use of resins that have a discrete capacity for the absorption of ions. When this capacity has been utilized, the absorbed minerals have to be removed from the resin by regeneration before it can be re-used. The objective of this study was to assess the effectiveness of a cation exchange resin for eliminating cations from cheese whey using a single column cation exchanger, with particular importance placed on the improvement of flovor. Experimental Materials Cheese milk was cooled to 4C immediately after milking and held at this temperature prior to pasteurization. The milk was then pasteurized at 72C for 15 seconds and acidified using a culture of selected lactic acid-producing bacteria to achieve a uniform and predictable rate of acid production. Coagulation was achieved using bacterial renin. The curd was then cut for dehydration and the watery part remaining from the milk after separation of the curd was collected for further analyses. The resin, a strong-acid cation exchanger, was produced by Zalion [Zalion Co., Tehran, Iran]. All chemicals used were reagent grade and purchased from Merck Co. [Merck Co., Germany]. Ion Exchange Treatment For the regeneration of the cation exchanger, 1 M NaCI was used. A onecolumn treatment was carried out by passing whey through a 20× 100 cm column. A uniform bed column of resin was prepared by packing a slurry of the cation exchanger in 1 M NaCI. The effluents of each run of ion-exchanged whey were collected for chemical analyses.