Contents lists available at ScienceDirect Small Ruminant Research journal homepage: www.elsevier.com/locate/smallrumres Short communication Effects of feeding system, heat treatment and season on phenolic compounds and antioxidant capacity in goat milk, whey and cheese Jorge L. Chávez-Servín, Héctor M. Andrade-Montemayor, Cecilia Velázquez Vázquez, Araceli Aguilera Barreyro, Teresa García-Gasca, Roberto A. Ferríz Martínez, Andrea M. Olvera Ramírez, Karina de la Torre-Carbot ⁎ Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Querétaro, Qro. CP 76320, Mexico ARTICLE INFO Keywords: Phenolic compounds Antioxidant capacity Goat dairy products Feeding systems ABSTRACT Phenolic compounds are present in goat milk and cheese. The composition of goat milk and its products may vary depending on factors such as season, feeding system and heat treatment. The aim of this work is to quantify total phenolic compounds (TPC) and antioxidant capacity in pasteurized and unpasteurized samples of milk, milk whey, and cheese from goats fed in two different systems (free-range grazing and permanent confinement), during dry and rainy seasons. TPC concentrations were highest in unpasteurized samples from dry season compared to pasteurized and rainy season: 132.4 ± 27.3, 76.5 ± 5.77 mg of gallic acid equivalent (GAE)/L for unpasteurized milk and milk whey, respectively, and 363.21 ± 52.97 mg GAE/Kg for cheese. Antioxidant ca- pacity for dry season produce was significantly higher (P< 0.05) than rainy season produce. Free-range grazing was found to be a good option for producing a higher concentration of phenolic compounds and a higher antioxidant capacity. 1. Introduction Goat milk and its derivatives are regaining prominence in the human diet due to their composition and recognized benefits for human health (Raynal-Ljutovac et al., 2008). Goat milk and its products are superior to cow's milk in a number of aspects: lower allergenicity of their proteins, greater digestibility and more bioactive components, among others. Because of these, goat milk has gained the image of being a healthy, functional product (Albenzio et al., 2012; Raynal- Ljutovac et al., 2008). There have been a number of recent studies on phenolic compounds in foods, showing their benefits by reducing pathogenesis or severity of chronic disease, including cardiovascular disease (Lewandowska et al., 2016; Rangel-Huerta et al., 2015; Redan et al., 2016). But phenolic compound content in goat milk and dairy products like cheese and whey has so far been little studied (Hilario et al., 2010). The feeding system used–free-range grazing or permanent con- finement–has been found to affect the composition of goat milk, and may influence antioxidant activity, not only in the milk, but in milk products as well (Jordan et al., 2010; Keles et al., 2017). Other factors that can affect composition is the season of the year (rainy or dry) and the thermal treatment (pasteurization) process (Di et al., 2015; Hilario et al., 2010). Data on goat milk phenolic content and antioxidant capacity can be used to improve goat milk quality and therefore it is important to assess the impact of each of these factors on the composition of goat milk and goat milk products. Accordingly, the aim of this study was to measure and compare the total phenolic compound (TPC) concentration and antioxidant capacity in pasteurized and unpasteurized samples of milk, cheese and whey from goats fed in permanent confinement and free- range grazing, during dry and rainy seasons. 2. Materials and methods 2.1. Study design Healthy, multiparous goats, on their 2nd or 3rd lactation, from the Alpine breed were used, with an average weight of 50 ± 5 kg and an average milk production of 2.5 ± 0.4 kg/day. The milk samples were drawn after 60 days of lactation. The goats were raised in the state of Querétaro, in the municipality of El Marques, on the Amazcala Campus of the Autonomous University of Querétaro (UAQ). Animal welfare principles of the good practices manual for caprine milk production were followed (Kilkenny et al., 2017; SAGARPA, 2014). The project was https://doi.org/10.1016/j.smallrumres.2018.01.011 Received 16 September 2017; Received in revised form 19 January 2018; Accepted 21 January 2018 ⁎ Corresponding author. E-mail address: karina.delatorre@uaq.mx (K. de la Torre-Carbot). Small Ruminant Research 160 (2018) 54–58 Available online 31 January 2018 0921-4488/ © 2018 Published by Elsevier B.V. T