Highlights
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- Pullulan film gained antimicrobial and antioxidant properties after incorporating sweet basil extract (SBE).
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- We observed great antifungal efficacy of pullulan coating containing SBE on apples.
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- The application of coatings to apples also reduced changes of quality parameters.
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- Coated apples presented better overall preference than uncoated apples.
Abstract
The
antimicrobial and antioxidant activities of pullulan films containing
sweet basil extract (SBE) at varying concentrations were examined in the
paper. Additionally, the content of bioactives in SBE was determined. A
strong correlation was noted between SBE concentrations in the film and
the obtained film thickness. Pullulan film containing SBE was
characterized by a smooth surface as well as a uniform and compact
internal structure. The study involved an examination of the
effectiveness of pullulan coatings containing 24 mg SBE/cm2
on the prolongation of the shelf life of “Jonagored” apples. Pullulan
coating with SBE was found to offer low antibacterial activity against
mesophilic bacteria and good antifungal protection against Rhizopus arrhizus
on apple surfaces. This coating also contributed to a reduction in
weight losses and lower changes in the color and soluble solids of
fruits during storage. Apples with pullulan enriched SBE coating
presented better overall preference parameters.
Industrial relevance
The
consumers express an increasing aversion and objections towards an
application of chemical means in order to prolong the durability of food
products. This prompts food producers to search for new methods of
preventing raw materials against harmful microbial activity. Plant
extracts, due to their chemical variability, ensure unlimited
possibilities of microorganism growth control. An application of natural
plant extracts combined with edible coatings for fruit and vegetable
durability prolongation may find an acceptance among the consumers.
Incorporation of plant extract to edible coating ensures slow release of
bioactives on food surface, i.e. at the site of the highest
microbiological food changes. Pullulan is a natural polysaccharide, a
carrier of small energy amounts, forming glossy, colorless and
flavorless films, resistant to oils and impermeable for oxygen. The
authors decided to elaborate the procedure concerning an application of
edible pullulan coating combined with sweet basil extract for an
elongation of apple durability, which will improve the quality of fresh
fruits during their storage and in the trade.
Keywords
- Edible coating;
- Pullulan;
- Basil extract;
- Apple;
- SEM
- Corresponding author. Tel.:
+ 48 22 5937650; fax: + 48 22 5937681.
Copyright © 2014 Elsevier Ltd. All rights reserved.
