Browsing by Author "Tuukkanen, Eija"

An edible coating is defined as a thin layer of material, which can be eaten as part of the whole product. The literature review focused on edible coating materials, the preparation of the coat-ings and coating applications. The aim of the experimental work was to determine the suitability of different coating materials as an edible coating on the surface of the fresh cut carrots and parsnips and how roasting affected the coatings and coated root vegetables. The root vegetables were coated with three types of emulsions which were made from the soy protein isolate, chi-tosan and hydroxypropyl methylcellulose (HPMC K4M) using the dipping method. Further-more, the thyme essential oil was added to the coatings, mainly to provide aroma. The study also contained uncoated root vegetables. The samples were stored in a plastic bag or without a plastic bag. The shelf life of root vegetables was measured as the change in the weight caused by the loss of water vapor. The effect on the roasting was studied by baking loss, firmness and colour measurements. All tested coatings improved the appearance of root vegetables after the roasting and they did not impair the taste of root vegetables. The chitosan coating was the most suitable for the fresh cut and roasted root vegetables though further studies are needed to achieve optimal edible coatings for roasting. The coated carrots in a bag were redder than the uncoated carrots in a bag thus the colour was better preserved in the coated carrots. The coating itself was not enough to keep the root vegetables fresh during the storage. After roasting the root vegetables without the bag were considerably harder than the root vegetables in the bag. It is challenging to develop edible coatings suitable for the fresh cut and roasted vegetables. Coating has to stay on the surface of the vegetable and the properties of the coating must be designed for the vegetable in question. The moisture, respiration and purpose of use of the vege-table must be taken into consideration when developing such a coating.