1.2.2. Influence on nutritional attributes
Apple and pear cultivars are well known for being good sources of antioxidant properties, especially for their content of polyphenolic compounds concentrated in their skin. Apples contain natural sugars, organic acids, dietary fiber, minerals and vitamins, whereas pears are good sources of fiber and micronutrients such as chlorogenic acid, flavonols and arbutin (Sinha 2012). In general, pear juice is characterized by similar soluble solids content than apple juices but in sugar free extract sorbitol has higher contribution which content is estimated at 10-25 g/L (Dietrich et al. 2007).
Thermal processing inactivates spoiling microorganisms efficiently, but may also degrade nutritional quality of foods …show more content…
Due to the general low acidity of pears, the addition of anti-browning agents to pear juice can lower the pH with a suitable sugar-acid ratio. According to Jiang et al. (2016b), ascorbic acid addition of 0.20% might solve the browning problem as well as improve the antioxidant capacity of pear juice.
1.2.3. Influence on organoleptic attributes
Thermal pasteurization of apple and pear juices is effective in preventing microbial spoilage and extends their shelf life. However, these treatments induce a negative impact on their natural flavor and color that is perceived by consumers (Mak et al. 2001).
1.2.3.1. Changes in aroma …show more content…
In general, HTST treatment can promote the inactivation of these enzymes but their action begins from initial processing steps such as the breakage of the fruit during the juice extraction process (Krapfenbauer et al. 2006). In addition to heat treatments, other methods including blanching, pectolytic enzyme treatments or the use of antibrowning agents are some the strategies to control browning and cloud destabilization (Fukutami et al. 1986; Gierschener & Baumann 1988; Castaldo & Loiudice 1997; Quoc et al. 2000; Riahi & Ramaswamy 2003). Krapfenbauer et al. (2006) focused their study on the impact of HTST treatment combinations (60-90 ºC for 20-100 s) on enzymatic browning and cloud stability of different apple juices considering eight apple varieties. They concluded that HTST at 80 ºC inactivated PPO and reduced PE activity at 50%. In addition, they indicated that the best stability of cloud and color in relation to heat treatment was observed at 70 ºC/100 s and 80 ºC/20
Apple and pear cultivars are well known for being good sources of antioxidant properties, especially for their content of polyphenolic compounds concentrated in their skin. Apples contain natural sugars, organic acids, dietary fiber, minerals and vitamins, whereas pears are good sources of fiber and micronutrients such as chlorogenic acid, flavonols and arbutin (Sinha 2012). In general, pear juice is characterized by similar soluble solids content than apple juices but in sugar free extract sorbitol has higher contribution which content is estimated at 10-25 g/L (Dietrich et al. 2007).
Thermal processing inactivates spoiling microorganisms efficiently, but may also degrade nutritional quality of foods …show more content…
Due to the general low acidity of pears, the addition of anti-browning agents to pear juice can lower the pH with a suitable sugar-acid ratio. According to Jiang et al. (2016b), ascorbic acid addition of 0.20% might solve the browning problem as well as improve the antioxidant capacity of pear juice.
1.2.3. Influence on organoleptic attributes
Thermal pasteurization of apple and pear juices is effective in preventing microbial spoilage and extends their shelf life. However, these treatments induce a negative impact on their natural flavor and color that is perceived by consumers (Mak et al. 2001).
1.2.3.1. Changes in aroma …show more content…
In general, HTST treatment can promote the inactivation of these enzymes but their action begins from initial processing steps such as the breakage of the fruit during the juice extraction process (Krapfenbauer et al. 2006). In addition to heat treatments, other methods including blanching, pectolytic enzyme treatments or the use of antibrowning agents are some the strategies to control browning and cloud destabilization (Fukutami et al. 1986; Gierschener & Baumann 1988; Castaldo & Loiudice 1997; Quoc et al. 2000; Riahi & Ramaswamy 2003). Krapfenbauer et al. (2006) focused their study on the impact of HTST treatment combinations (60-90 ºC for 20-100 s) on enzymatic browning and cloud stability of different apple juices considering eight apple varieties. They concluded that HTST at 80 ºC inactivated PPO and reduced PE activity at 50%. In addition, they indicated that the best stability of cloud and color in relation to heat treatment was observed at 70 ºC/100 s and 80 ºC/20