Application of palladium-based oxygen scavenger to extend the mould free shelf life of bakery products

Nadine Rüegg,Bettina Röcker,Selçuk Yildirim

doi:10.1016/j.fpsl.2021.100771

Nadine Rüegg, Bettina Röcker + Show 1 more

Open Access

https://doi.org/10.1016/j.fpsl.2021.100771

Copy DOI

Abstract

An oxygen scavenging film based on a catalytic system with palladium (CSP) was combined with modified atmosphere (MA) packaging to extend the mould free shelf life (MFSL) of bakery products. Par-baked buns, toast bread and gluten-free bread inoculated with Aspergillus niger spores were packed in normal atmosphere (NA) and under MA (with 2 vol.-% of O2) with or without CSP. Mould growth was detected after 2–3 days on all products packed under NA as well as under MA without CO2 and CSP. Use of CO2 in MA extended the MFSL by 8–10 days, 16–18 days and 3–4 days for par-baked buns, toast and gluten-free bread, respectively. Use of CSP with MA reduced the oxygen concentration in headspace from 2 vol.-% to < 0.01 vol.-% within 105–190 min with all bakery products. This led to a further increase in MFSL of bakery products by 3–9 days.

Highlights

Shelf life of bakery products like bread and buns is mainly limited by staling and microbial growth
By the use of CO2 in the modified atmosphere (MA) mould free shelf life was extended to 10–12 days for par-baked buns, to 17 – 19 days for toast bread slices and to 4–5 days for gluten-free bread slices
The use of the catalytic system with palladium (CSP) enabled a fast reduction in headspace oxygen concentration of all tested bakery products to below 0.01 vol.-%

Summary

Introduction

Shelf life of bakery products like bread and buns is mainly limited by staling and microbial growth. It has been shown that the microbial spoilage of bakery products is mostly attributed to moulds like Penicillium spp. and Aspergillus niger (Legan & Voysey, 1991). Commonly known as chalk moulds, are important spoilers of bread (Deak, 2007; Legan & Voysey, 1991; Nielsen & Rios, 2000; Smith, Daifas, El-Khoury, Koukoutsis, & El-Khoury, 2004). To retard microbial spoilage in bakery products, antimicrobial preservatives including organic acids (propionic, benzoic, sorbic, acetic and their salts) and ethanol is used (Smith et al, 2004)

Objectives

Methods

Findings

Conclusion