ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of oxygen scavenger screw-caps on quality of pineapple juices

Ján Durec, Blanka Tobolková, Elena Belajová, Martin Polovka, and Ľubomír Daško

McCarter Ltd., Bratislava, Slovakia

E-mail: blanka.tobolkova@nppc.sk

Received: 4 March 2020  Accepted: 26 May 2020

Abstract:

Effect of screw-caps with oxygen scavenger bound inside the bore seal of the closure (screw-cap-O₂S) was studied on dynamics of ascorbic acid (AA), 5-hydroxymethylfurfural (HMF), antioxidant activity expressed as Trolox equivalent (TEAC) and ascorbic acid equivalent (AAE), total polyphenols content (TPC) and colour changes in pineapple juices stored for 90 days. Results were compared to juices closed with conventionally used screw-caps. Screw-caps with bound oxygen scavenger revealed a stabilization effect on ascorbic acid concentration and colour of pineapple juices. Concentration of ascorbic acid (AA) was significantly lower (p < 0.05) in juices with conventional screw-caps, whereas a* values (redness/greenness) and browning indexes (BI) of these juices were higher (p < 0.05) than those in juices with screw-cap-O₂S. Changes in AA and b* values (yellowness) significantly affected BI and total colour difference (ΔE). Gradual increase in HMF (maximum concentration at a level of 2.76 mg l⁻¹) was related to AA degradation (r = − 0.815 to − 0.819). Although lower increase in HMF concentration was observed in juices with screw-cap-O₂S (increase by 99%) compared to juices with conventional closure (increase by 178%), difference among both juices was nonsignificant (p > 0.05). Effect of different screw-caps and storage conditions on TPC and AAE values was negligible (p > 0.05). Formation of low molecular weight phenolic fractions and the existence of dynamic processes leading to the formation/elimination of compounds with anti- or pro-oxidant properties are supposed.

Keywords: Pineapple juice; Screw-cap; Oxygen scavenger; Juice quality

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01226-x

Chemical Papers 74 (12) 4181–4191 (2020)