Pilot-scale production of cloudy juice from low-quality pear fruit under low-oxygen conditions

• Published in: Food chemistry 2015-04, Vol.173, p.827-837
• Main Authors: De Paepe, Domien, Coudijzer, Katleen, Noten, Bart, Valkenborg, Dirk, Servaes, Kelly, De Loose, Marc, Diels, Ludo, Voorspoels, Stefan, Van Droogenbroeck, Bart
• Format: Article
• Language: English
• Subjects: Beverages; Food Industry - methods; Fruit - chemistry; Oxygen; Pear juice; Phenolic compounds; Phenols - analysis; Pilot-scale; Pyrus - chemistry; Spiral-filter press
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.10.018

•Cloudy pear juice production from low-quality pear fruit under low-oxygen conditions.•A maximum juice yield of 78% could be obtained.•Enzymatic browning during juice extraction could be suppressed. In this study, a process for the production of premium quality yellowish, cloudy pear juice from low-quality fruit under low-oxygen conditions was developed. The production process consisted of (1) shredding, (2) pressing with spiral-filter technology including a vacuumised extraction cell, (3) holding in an inert gas buffer tank, (4) pasteurisation, (5) and refrigerated storage. First, the system parameters of a spiral-filter press were optimised with the aim of producing a yellowish, cloudy pear juice with the highest possible juice yield. A maximum juice yield of 78% could be obtained. Enzymatic browning during juice extraction could be suppressed as a result of the fast processing and the low air (oxygen) levels in the extraction chamber of the spiral-filter press. Furthermore, we observed that instantaneous pasteurisation at 107°C for 6s, subsequent aluminium laminate packaging and cold storage had only a minimum effect on the phenolic composition.