Effect of cream fermentation on microbiological, physicochemical and rheological properties of L. helveticus-butter Joo-Ann Ewe ⇑ , Su-Yi Loo School of Biosciences, Taylor’s University, No 1, Jalan Taylors, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia article info Article history: Received 23 June 2015 Received in revised form 18 November 2015 Accepted 12 January 2016 Available online 13 January 2016 Keywords: Butter Cream Fermentation L. helveticus Rheology Physicochemical properties Fatty acids composition abstract The primary objective of this study was to evaluate the physicochemical and rheological properties of butter produced by Lactobacillus helveticus fermented cream. The incorporation of putative probiotic – the L. helveticus, to ferment cream prior to butter production was anticipated to alter the nutritional com- position of butter. Changes in crude macronutrients and the resultant modification relating to textural properties of butter induced upon metabolic activities of L. helveticus in cream were focused in this research. Fermented butter (LH-butter) was produced by churning the cream that was fermented by lactobacilli at 37 °C for 24 h. Physicochemical analysis, proximate analysis and rheology properties of LH-butter were compared with butter produced using unfermented cream (control). LH-butter showed a significantly (P < 0.05) higher fat content and acid value; lower moisture and ash; and was softer than the control. Cream fermentation modified nutritional and textural properties of butter in which LH-butter contained higher health beneficial unsaturated fatty acids than the control and thus rendered the product softer. Its enrichment with probiotics could thus further enhance its functional property. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction Fermentation of food is one of the earliest food processing methods known by man. It is a metabolic process by yeast or bac- teria that converts sugar into organic acid, alcohol and carbon dioxide under anaerobic condition. The resulting metabolites pro- duced during fermentation can then enhance a food’s flavour pro- file, nutritional value, as well as serving the preservation purpose (Caplice & Fitzgerald, 1999). In addition to these valuable charac- teristics, fermentation by microorganisms could enrich the prod- ucts further, providing excellent source of health beneficial bioactive compounds (Ewe, Wan-Abdullah, Karim, Bhat, & Liong, 2010). Butter should be a solid product made from milk or cream, according to Food Regulation 1985 (Malaysia). It contains 80% fat, 16% water and 4% solids non-fat (SNF), such as carbohydrate and protein (Frede, 2002). Industrial production of butter involves the usage of cream as the raw material (Nollet & Toldra, 2010) and is converted from oil-in-water emulsions to water-in-oil emulsions by high-speed churning (Samet-Bali, Ayadi, & Attia, 2009). Cultured butter is a condiment that is produced under an uncontrolled fermentation manner/natural fermentation manner, such as Tunisian butter (Samet-Bali et al., 2009). The taste and aroma of cultured butter highly depends on the microorganisms which reside and ferment the cream. However, it is more aromatic and tangy, as well as having longer shelf life and better texture than normal non-fermented butter (Caplice & Fitzgerald, 1999). Lactic acid bacteria (LAB) have long been used as a starter culture for the production of various dairy products, such as yogurt, lassi and cheese, which could also be incorporated into cream for the production of butter with enhanced bioactivity and flavour devel- opment. By possessing lipase and esterase, LAB is able to utilise fat in the cream and convert it to phospholipids, fatty acids, mono- and diglycerides (Fenster, Parkin, & Steele, 2000). Protein can be degraded by peptidase into peptides and amino acids while lactose can be hydrolysed into lactic acid by lactase (Minervini, 2011). Being a putative candidate for probiotics, the incorporation of LAB for fermentation has indeed further enriched the nutritional composition of dairy products with health beneficial effects beyond what it could normally confer (Lye, Kuan, Ewe, Fung, & Liong, 2009). To date, butter produced using fermented cream can scarcely be found in the market. The controlled fermentation of cream with LAB could provide consumers with the beneficial effects of fermented-butter (butter produced from fermented cream) as well as probiotics. Therefore, probiotic-fermented-butter may be an excellent alternative to currently available dairy products on the http://dx.doi.org/10.1016/j.foodchem.2016.01.049 0308-8146/Ó 2016 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: jooann.ewe@taylors.edu.my (J.-A. Ewe). Food Chemistry 201 (2016) 29–36 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem