Valorisation of side streams




Eva Margrét Jónudóttir, Matís; Ólafur Reykdal, Matís; Helga Gunnlaugsdóttir, Orkídea; Sophie Jensen, Matís; Léhna Labat, Matís; Þóra Valsdóttir, Matís; Guðrún Birna Brynjarsdóttir, Farmers Association of Iceland; Valur Klemensson, Farmers Association of Iceland and Rósa Jónsdóttir, Matís

Supported by:

Food Foundation / Icelandic Food Innovation Fund


Eva Margrét Jónudóttir

Project Manager

The main goal of the project "Value addition of side products from horticulture" was to find ways to use side products from horticulture production for increased value creation and also to reduce waste in vegetable production. Different by-products were examined, including what falls from the defoliation of tomato and cucumber plants, leaves from outdoor vegetables such as cauliflower and broccoli, as well as leaves and stems from rose cultivation. The basis for improved utilization of secondary products and excess quantities of potatoes and carrots through biomass processing and product development was also examined. It was examined whether the consumption of by-products was safe with appropriate risk analysis and chemical measurements, and the main information on possible negative health effects was compiled.

Information on the chemical content of different by-products is now available. A significant number of samples reached the limit for several additives, viz. 15% of the nutritional reference value (NV), and thus there is a possibility of labeling the relevant supplement on the packaging of by-products if they are sold directly as food. Biomass processing of second class potatoes and beets was tested and the total amount of polyphenols as well as antioxidant activity was investigated. The total amount of polyphenols and antioxidant activity were studied in leaves and branches of cauliflower, broccoli, tomato, cucumber and roses. The total amount of polyphenols was high in extracts of rose petals and branches as well as antioxidant activity and "anti-aging" activity. Subsequently, it was decided to test its use as an ingredient in skin care products. The processing characteristics of yellow beets were examined in terms of shelf life and sensory aspects. Two different recipes of spice mixes were developed that included both side products from cauliflower and broccoli cultivation. Products from biomass processing such as starch and fiber were tested in the recipes of the spice mixture with reasonable results. There can be various shortcomings in the use of horticultural by-products in food, and several things must be considered. The main hazards associated with the consumption of vegetables and their by-products can be classified into microbial contamination, unwanted substances and foreign bodies.

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