Polyphenol oxidase (PPO) catalyses the browning reaction during fruit processing and storage. It is considered a threat to clean labels and minimally processed fruit products. Unwanted changes in fruits’ appearance and quality represent a cost to the industry. High pressure and ultrasound, in addition to thermal treatment, are effective in reducing PPO activity and producing high-quality products. PPO from different fruit cultivars behaves differently when submitted to different treatments. A systematic review was conducted, where treatment parameters, PPO inactivation data (≥80% inactivation), and kinetic inactivation parameters (rate constant (k), activation energy (Ea), D-value, and z-value) by different treatments were collected. Additionally, the estimated energy requirements for the inactivation of PPO (≥80%) by different treatments were calculated and compared. Resistance to various treatments varies between fruit cultivars. For the same temperature, the inactivation of PPO by ultrasound combined with heat is more effective than thermal treatment alone, and the high pressure combined thermal process. The majority of the thermal, HPP, and ultrasound inactivation of PPO in fruits followed first-order behaviour. Some fruit cultivars, however, showed biphasic inactivation behaviour. The estimated specific energy requirements calculated based on the mass of processed fruit sample to inactivate ≥80% polyphenol oxidase for the thermal process was 87 to 255 kJ/kg, while for high pressure processing it was 139 to 269 kJ/kg and for ultrasound it was 780 to 10,814 kJ/kg.
Asia has seen the most significant increase in goat milk production (22%) over the last decade between 2007 and 2017, followed by Africa (13%), Oceania (9%), the Americas (5%), and Europe (4%) (Miller & Lu, 2019). Goat milk is a wholesome and nutritious milk drink that has good digestibility, alkalinity, buffering capacity, and certain therapeutic values in medicine and human nutrition, which differs from cow milk (Park, 2007). The digestibility of goat milk is due to the size of casein which is smaller and smoother than that of cow's milk (Yadav et al., 2016). It can be readily consumed by the digestive system compared to cow's milk and is also ideal for babies and lactose intolerants (Haenlein, 2004;Park, 2007;Yadav et al., 2016).Currently, high-quality and safe milk products are demanded by consumers worldwide. These products should have a fresh-like characteristic in terms of flavor, texture, color, nutrient, and aroma with an extended shelf life (Ozcan et al., 2017;Trujillo et al., 2002).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.