Citation: Ruchira Nandasiri, HP Vasantha Rupasinghe. Inhibition of Low Density Lipoprotein Oxidation and Angiotensin Converting Enzyme in vitro by Functional Fruit Vinegar Beverages. J Food Processing & Beverages. 2013;1(1): 4. J Food Processing & Beverages September 2013 Vol.:1, Issue:2 © All rights are reserved by Ruchira Nandasiri et al. Inhibition of Low Density Lipoprotein Oxidation and Angiotensin Converting Enzyme in vitro by Functional Fruit Vinegar Beverages Ke ywords: Antio xid a nts; AC E inhib itio n; LDL o xid a tio n; Ac e tic a c id ; Hyp e rte nsio n; Fruit vine g a r b e ve ra g e s Abstra c t Fruit vine g a r b e ve ra g e s ha ve b e e n b e c o ming p o p ula r a s a p a rt o f the he a lthy d ie t. The c urre nt stud y inve stig a te d the a ntio xid a nt a nd in vitro lo w d e nsity lip o p ro te in (LDL) o xid a tio n inhib itio n a nd a ng io te nsin c o nve rting e nzyme (AC E) p ro p e rtie s o f fo ur d iffe re nt fruit vine g a r b e ve ra g e s: a p p le , b lue b e rry, c ra nb e rry a nd to ma to a t 5, 10, a nd 15 mg a c e tic a c id e q uiva le nts/ g c o nc e ntra tio ns. Blue b e rry vine g a r b e ve ra g e sho we d the hig he st a ntio xid a nt c a p a c ity re g a rd le ss the a c e tic a c id c o nc e ntra tio n. O ve r 50% LDL o xid a tio n inhib itio n in vitro wa s o b se rve d fo r c ra nb e rry (me a n ± SD) (68 ± 1.7%) a nd b lue b e rry (85 ± 1.5%) vine g a r b e ve ra g e s a t the thre e a c e tic a c id c o nc e ntra tio ns. Bo th c ra nb e rry (92 ± 0.2%) a nd b lue b e rry (60 ± 0.7%) vine g a r b e ve ra g e s ha d hig he r le ve ls o f AC E inhib itio n in vitro at 15 mg ac etic a c id e q uiva le nts/ g c o nc e ntra tio n. C o mp a ra tive ly, to ma to vine g a r b e ve ra g e sho we d lo we r a ntio xid a nt a nd AC E inhib itio n p ro p e rtie s in vitro . Thus, fndings of the current study suggest that functional b e ve ra g e s, suc h a s fruit vine g a r b e ve ra g e s, c o uld b e a n a lte rna tive to d rug s in c o ntro lling hyp e rte nsio n a nd hyp e rc ho le ste ro le mia up o n the confrmation of the results, using an animal model in vivo . Introduction Fruits and vegetables are known to be a good source of biologically active plant secondary metabolites such as polyphenol compounds [1]. Te complex mixture of phytochemicals present in fruits and vegetables provides protective health benefts, mainly through additive and/or synergistic efects [2]. Furthermore, these polyphenol compounds have been found to exhibit strong antioxidant properties both in vitro and in vivo [1]. Even though many studies have investigated the in vitro antioxidant properties including the efects of apples [2], berries [1,3] and tomatoes [4] on inhibition of LDL oxidation, there are a very few studies conducted to investigate the in vitro antioxidant properties of functional fruit vinegar beverages to our best understanding. Fruit vinegar beverages are one of the emerging functional beverages in the North American market. A fruit vinegar beverage is defned as a beverage that has been fermented from at least one kind of fruit and each litre of beverage must contain more than 300 g of fruit juice [5]. Fruit vinegar beverages have been categorized into two diferent types based on their acetic acid concentration: fruit vinegar beverage, which is low in acetic acid (< 3% v/v) and concentrated fruit vinegar beverage, which is high in acetic acid (5 - 7% v/v) [5]. Total sugar content, the titratable acidity level, total soluble solids content and density of the fruit vinegar beverage may depend on the method of fermentation and the concentration of acetic acid content [5,6]. Te key organic acid associated with fruit vinegar beverage is acetic acid [5,6]. Furthermore, these fruit vinegars consist of high concentrations of polyphenolic compounds [7]. However, to produce a consumer acceptable fruit vinegar beverage, the choice of raw materials and the method of acetifcation are major important factors to be considered [8]. Apples, berries and tomatoes have distinct polyphenolic compositions and are well known for their health promoting properties [9-11]. Although, there are innumerable studies on the health benefts of fresh as well as processed fruit products, efects of fruit vinegar beverages on vascular function and blood pressure are largely unknown. Terefore, this study was carried out as an initial step to assess the in vitro antioxidant capacities, LDL oxidation inhibition and ACE inhibition ability of a fruit vinegar beverage developed using apples, berries and tomatoes. Te current study evaluated the antioxidant and antihypertensive properties of four different fruit vinegar beverages: apple, blueberry, cranberry and tomato at 0.5%, 1.0%, and 1.5% acetic acid concentrations. Materials and Methods Samples and Chemical Reagents Apples and tomatoes were purchased from a local grocery store (Sobeys, Truro, NS, Canada), Concentrated cranberry juice was purchased from a commercial cranberry juice manufacturer (Cranberry Acres, Berwick, NS, Canada) and blueberry juice (100% juice) was purchased from a commercial blueberry juice manufacturer (Van Dyke, Caledonia, Queens Co., NS, and Canada). Sample Preparation Fruit vinegar beverages were developed using the methods by Su and Chien [8] and Nakamura [12] with modifcations. Te method in brief is as follows (Figure 1). Good quality raw materials (apples and tomato) were selected and washed and then pressed using an X1 hydraulic plate presser (Model JVH 56C17F5323J, Marathon, WI, USA). A total of about 8 kg of apple or tomato fruits were required to obtain 4 L of juice (about 50% yield from the X1 hydraulic plate presser). Te pressed juice sample was fltered using four layers of Ruchira Nandasiri, H. P. Vasantha Rupasinghe* Department of Environmental Science, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, Nova Scotia, Canada B2N 5E3 *Address for Correspondence H. P. Vasantha Rupasinghe, Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Room 219-3 Cox Building, 50 Pictou Road (PO Box 550), Truro, NS B2N 5E3 Canada, Tel: 902-893- 6623; Fax: 902-893-1404; Email: vrupasinghe@dal.ca Submission: 21 August 2013 Accepted: 19 September 2013 Published: 27 September 2013 Research Article Open Access Journal of Food Processing & Beverages Avens Publishing Group Invi ting Innovations Copyright: © 2013 Nandasiri R, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.