Raziskovalni projekti

Fruit and vegetables are essential components of the human diet, as they provide most of the vitamins and minerals we need. The recommended daily intake of fruit and vegetables is 400 g per person. In Slovenia, due to the low level of self-sufficiency in fruit and vegetables (less than 30%), domestic production cannot meet demand, and the shortfall is covered by imports. This often raises the question of local versus imported produce, particularly in terms of freshness, shelf life and quality.

Due to longer transport distances, imported fruit and vegetables may have lower freshness and quality. Long transport times can lead to losses of nutrients and flavour due to earlier harvesting and inadequate storage conditions, particularly affecting vitamins, which are especially sensitive and have limited stability. Vitamins are a group of organic compounds essential for the normal functioning of the human body. Most cannot be synthesised by the body and must therefore be obtained through food. Vitamins act as catalysts in biochemical reactions, support the immune system, contribute to the normal functioning of the nervous system, participate in nutrient metabolism, and help maintain healthy skin, eyes and bones. They are divided into two main groups: i) water-soluble vitamins (vitamin C and B-complex vitamins) and ii) fat-soluble vitamins (vitamins A, D, E and K). Each vitamin has specific functions, and a deficiency of any vitamin can lead to various health problems.

Over the past 50 years, the average vitamin A content has decreased by 18%, riboflavin by 38% and vitamin C by 15% across 43 different types of fruit and vegetables, mainly due to soil degradation, climate change, higher water content in produce, longer storage and transport. Imported fruit and vegetables may contain up to 100% fewer vitamins than locally produced fruit and vegetables. In addition to having a higher carbon footprint, which contributes significantly to climate change, and a lower vitamin content, imported fruit and vegetables may contain plant protection products (PPPs) that are not authorised in Slovenia or the EU, potentially posing risks to consumer health and the environment.

Fruit and vegetables are affected by numerous diseases and pests. To produce sufficient quantities of food, fruit and vegetable growers need to use plant protection products (PPPs). After application to plants, the active substances contained in PPPs evaporate from plant surfaces, degrade and are transformed through metabolic processes in and on the plant. Fruit and vegetables may therefore contain PPP residues after treatment. Fruit has been particularly affected; between 2001 and 2009, it was the food group in Slovenia with the highest burden of PPP residues (Baša Česnik and Velikonja Bolta, 2015).

Today’s consumers demand not only healthy food rich in vitamins but also safe food containing as few PPP residues as possible. Trading limits are established at EU level by Regulation (EC) No 396/2005 as maximum residue levels (MRLs). National monitoring alone is not sufficient to establish the actual situation on the market, as the EU requires Slovenia to analyse only 12 samples per year and the monitoring includes very few organic foods. Additional research is therefore needed. The European Food Safety Authority (EFSA) report for 2022 shows that only 1.8% of samples originating from EU countries, Norway and Liechtenstein contained PPP residues above the MRL. The situation was different for samples from third countries, where the proportion exceeding the MRL was 7.4% (EFSA, 2024). It is therefore relevant to investigate and compare PPP residues in locally produced and imported fruit and vegetables.

Project objectives

The objectives of the project are:

• to obtain relevant data on changes in the content of vitamins A, B, C and K in locally produced fruit and vegetables of greatest interest to consumers, from harvesting to retail shelves or markets;
• to compare vitamin content between the same species and varieties of locally produced and imported fruit and vegetables available on retail shelves;
• to obtain relevant data on the potential presence of pesticide active substances in locally produced fruit and vegetables and to compare their presence between the same varieties of locally produced and imported apples at full maturity.

The project will provide data on the safety (plant protection product residues – PPPs) and quality (content of vitamins A, B, C and K) of Slovenian fruit and vegetables, with the aim of protecting consumer health and raising awareness of the benefits of locally produced food.

If the research confirms that Slovenian produce contains fewer PPP residues and higher levels of vitamins than imported produce, this could further increase consumer confidence in Slovenian producers. Such findings could encourage greater demand for locally produced fruit and vegetables, thereby helping to reduce imports, strengthen self-sufficiency and accelerate the sustainable development of Slovenian agriculture.

Partnership

• Agricultural Institute of Slovenia
• University of Ljubljana, Biotechnical Faculty