International Dairy Journal 97 (2019) 139e148 Contents lists available at ScienceDirect International Dairy Journal journal homepage: www.elsevier.com/locate/idairyj Yoghurt added with Lactobacillus casei and sweetened with natural sweeteners and/or prebiotics: Implications on quality parameters and probiotic survival Guilherme M. Costa a, Marlon M. Paula a, Carlos Eduardo Barao~ a, Suellen J. Klososki a, * Elton G. Bonafe b, Jesuí V. Visentainer b, Adriano G. Cruz c, Tatiana Colombo Pimentel a, d, a Instituto Federal do Parana (IFPR) e Campus Paranavaí, Rua Jose Felipe Tequinha, 1400, Jardim das Naçoes,~ Paranavaí, Parana, 87703-536, Brazil b Universidade Estadual de Maringa (UEM), Departamento de Química, Av. Colombo, 5790, Jardim Universitario, 87020-900, Brazil c Instituto Federal de Educaçao,~ Ci^encia e Tecnologia do Rio de Janeiro (IFRJ), Departamento de Alimentos, 20270-021, Rio de Janeiro, Brazil d Universidade Pitagoras Unopar, Programa de Mestrado em Ci^encia e Tecnologia de Leite e Derivados, Rua Marselha, 591 Parque Res. Joao~ Piza, Londrina, Parana, 86041-120, Brazil article info abstract Article history: The effect of addition of natural sugar substitutes (stevia, erythritol or xylitol) and prebiotics (oligo- Received 25 November 2018 fructose or polydextrose) on physicochemical characteristics, probiotic survival (Lactobacillus casei) and Received in revised form sensory acceptance of yoghurts during storage (7 C, 28 days) was evaluated. Yoghurts with sucrose or 22 May 2019 sucralose were also prepared. Xylitol and sucralose added yoghurts had physicochemical characteristics Accepted 22 May 2019 and sensory acceptance similar to those of the product with sucrose. Xylitol was more efficient in Available online 4 June 2019 maintenance of textural characteristics and probiotic survival in simulated gastrointestinal conditions (SGIC) than sucralose. Addition of erythritol and stevia changed the textural parameters, reduced acceptance and decreased probiotic survival in SGIC. Addition of oligofructose or polydextrose improved texture and increased probiotic survival but decreased flavour acceptance. All formulations could be À considered probiotic products during shelf life (7 C, 28 days) with counts higher than 107 cfu mL 1 in À the product and 104 cfu mL 1 after SGIC. © 2019 Elsevier Ltd. All rights reserved. 1. Introduction (Furlan & Campderros, 2017). However, consumption of artificial sweeteners is associated to increased risk of type 2 diabetes Sucrose is the main ingredient used in the food industry for (Fagherazzi et al., 2017), higher body weight (Bian et al., 2017), promoting sweet taste, it can improve the consistency of products, increased cardiometabolic risk (Azad et al., 2017), and cytotoxic and and does not present bitter or residual tastes (Carocho, Morales, & mutagenic activities (Oliveira et al., 2017), among others. Ferreira, 2017). However, due to an increase in consumption of Thus, there is an increase in demand for natural and healthy foods with low or no sugars, the food industries are trying to products, increasing development of dairy products with natural include sugar substitutes in their formulations (Furlan & sweeteners (Miele et al., 2017) and/or added prebiotic components. Campderros, 2017; Gao, Brennan, Mason, & Brennan, 2017). The In the category of natural sweeteners are erythritol (produced by sucrose substitutes most used are artificial sweeteners, such as the fermentation of glucose using osmophilic yeasts; Carly et al., saccharin, acesulfame K, aspartame and sucralose (Miele et al., 2017), xylitol (obtained by microbial processes involving bacteria, 2017), the latter being considered the best substitute for sugar, fungi or yeasts and having as a substrate xylose or hemicellulose because it has slight residual bitter taste, stability to high temper- hydrolysates; Pappu & Gummadi, 2017), and stevia (extracted from ature and acidity and causes few sensorial alterations in products leaves of Stevia rebaudiana Bertoni; Gao et al., 2017). Among the prebiotic components are oligofructose and polydextrose, which can also be used as sugar substitutes, but it is recommended they be * Corresponding author. Tel.: þ55 44991019000. used with sweeteners, because of their low sweetener power E-mail address: [email protected] (T.C. Pimentel). (Apolinario et al., 2014). Prebiotic components can promote health https://doi.org/10.1016/j.idairyj.2019.05.007 0958-6946/© 2019 Elsevier Ltd. All rights reserved. 140 G.M. Costa et al. / International Dairy Journal 97 (2019) 139e148 benefits to consumers associated with modulation of their micro- (stevia B), ERY (erythritol), ERY-O (erythritol þ oligofructose) and biota (Das, Choudhary, & Thompson-Witrick, 2019; Gibson et al., ERY-P (erythritol þ polydextrose). The concentration of sweeteners 2017). was determined in preliminary tests using pairwise comparison Probiotics are living microorganisms, that confer beneficial ef- tests (Stone, 2012) to evaluate the sweet taste intensity. Thus, all fects on the individual, when administered in adequate amounts formulations had the same sweet taste intensity when compared (Hill et al., 2014). To exert a beneficial impact on consumer health, with the sucrose added product. The stevia sweeteners differed in probiotic cultures must be viable in the product throughout the rebaudioside content and were tested to observe if concentration of À shelf-life (>106 cfu mL 1)(Sangami & Sri, 2017; Savedboworn et al., this component resulted in higher acceptance of products by con- 2017). Survival depends on the conditions of the medium and in- sumers and better-quality products, as it is stated that stevia with gredients used. Only one study evaluated the effect of different higher rebaudioside content has lower bitter taste (Poele et al., sweeteners addition on the viability of probiotic cultures in yo- 2018). As the prebiotic components have low sweetening capacity ghurts (Vinderola, Costa, Regenhardt, & Reinheimer, 2002); how- (Apolinario et al., 2014), oligofructose and polydextrose were used ever, it used only traditional artificial sweeteners (aspartame and in association with erythritol, which was the natural sweetener acesulfame K). In addition, probiotics should be able to survive with the lowest sweetener capacity (70% of the sucrose sweetener under the conditions of the gastrointestinal tract, i.e., be resistant to power) (Carocho et al., 2017), aiming for synergism and cost stomach acidity and bile salts (Champagne, Gomes da Cruz, & Daga, reduction. Sucralose was used as control, because it is considered 2018). However, few studies take this latter aspect into account the artificial sweetener that best substitutes for sucrose (Furlan & when evaluating probiotic survival in dairy products. Campderros, 2017). The objective of the present study was to evaluate the effect of For yoghurt production, sucrose or the sweeteners/prebiotics À addition of natural sugar substitutes (stevia, erythritol or xylitol) and 35 g L 1 of skimmed milk powder (SMP) was added to full-fat and prebiotics (oligofructose or polydextrose) on the physico- milk. The SMP was used to adjust the total solids content and chemical characteristics, probiotic culture survival (Lactobacillus produce products with desirable texture characteristics. The casei) and sensory acceptance of yoghurts during refrigerated mixture was pasteurised at 85 C for 30 min in a water bath storage (7 C for 28 days). Sucrose and sucralose added products (Marconi®, Piracicaba, Brazil) and cooled to 42 C(Akalin, À were used as controls. Fenderya, & Akbulut, 2004). Then, 30 mL L 1 starter culture and À À 0.2 g L 1 probiotic culture (approximately 7.5 log cfu mL 1)were 2. Material and methods added; and the mix was incubated at 42 C for 5 h. After fermen- tation, the yoghurt was beaten, packed in translucent poly- 2.1. Material propylene plastic (52 mm high and 52 mm diameter) containers with 80 mL of capacity and stored at 7 C for 28 days. Oligofructose (P95, Orafti®, Tienen, Belgium), polydextrose (Tate & Lyle®, London, UK), xylitol (La Pianezza®, Santa Barbara do 2.4. Chemical composition and physicochemical analysis Oeste, Brazil), erythritol (La Pianezza®), stevia A (90% of rebau- dioside, Stevita®, Maringa, Brazil), stevia B (20% of rebaudioside, The chemical composition of the yoghurt formulations was Stevita®) and sucralose (Splenda, Tate & Lyle®) were used as determined on the 1st day of storage, according to the methodol- sweeteners or prebiotic components in the experiment. Strepto- ogies proposed by AOAC (2004). coccus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus The fatty acid profile was performed on the 1st day of storage. (YF-L812, Christian Hansen®, Valinhos, Brazil) were used as starter Fatty acid methyl esters (FAME) were prepared by methylation of cultures and L. casei (L. casei-01, Christian Hansen®) as probiotic total lipids, according to Florence et al. (2012). Methyl esters were culture. separated by gas chromatography using a Thermo model Trace Ultra 3300 (Thermo Scientific, Waltham, MA, USA) equipped with a 2.2. Starter culture preparation flame ionisation and cyanopropyl capillary column (100 m  0.25 i.d., 0.25-mm film thickness, CP-7420). Gas flow rates were À1 À1 The starter culture was prepared according to the recommen- 1.2 mL min carrier gas (H2), 30 mL min make-up gas (N2) and À1 dations of the manufacturer. The content of the package (25 g) was 35 and 350 mL min for the flame gases (H2 and synthetic air, poured into 1 L of