Analysis of Process Technologies to Preserve Berries

anglais. From all the wild berries that grow in Sweden only 2-5% is utilized (RISE, 2022). The United Nation has 17 goals for sustainable development, and many of those goals are related to sustainable food production (United Nations, 2022). A sustainable food product should have low environmental impact, social equity, and economic viability, while still containing essential nutrients (Woodhouse et al, 2018). There are many parameters to take into consideration when evaluating sustainability, as it is a complex system with many factors, I will only evaluate from the environmental impact perspective. The objective of this thesis is to analyze lyophilization, convective hot air drying, microwave vacuum drying, and osmotic dehydration to see if they are a better alternative to freezing berries, concerning cost of new equipment, environmental impact, preservation of nutrients, shelf life, and sensory properties. The berries considered are blueberries, bilberries, cranberries, and lingonberries because they have a similar composition. The study is conducted through a literature review. To evaluate the environmental impact of the mentioned technologies a sustainability checklist based on a Life Cycle Approach was conducted. The overall conclusion is that from all the assessed technologies in this thesis there is no better technique when it comes to preserve berries, all of them have their advantages and disadvantages, but to increase the utilization of the wild Swedish forest berries the development of a more efficient way to collect them could be an interesting project to develop.

anglais. “Is freezing the best way to preserve berries?” Consumption of berries is important because they are rich in antioxidants and vitamins. Sweden has a big production of berries but only 2-5% of the Swedish forest berries are utilized (RISE, 2022). The most common berries that grow in the Swedish forests are lingonberries and bilberries. Lingonberries and bilberries are very similar to cranberries and blueberries respectively. However, cranberries and blueberries are mostly imported to Sweden. Something that could help to increase the utilization of the wild berries is understand the advantages and disadvantages of the different technologies to preserve them. Freezing is one of the most common technologies to preserve berries, but there are other technologies like lyophilization, microwave-vacuum drying, hot air drying, and osmotic dehydration that could be a better alternative, these technologies are assessed on this thesis comparing cost of the equipment, sensory properties, shelf life, nutritional properties and the environmental impact that could have the different technologies. The information was obtained through a literature review and the sustainability assessment was done through a questionnaire based on a Life Cycle Approach. Since the berries are harvested once a year it is important to choose a good preservation technique to later produce healthy and tasty food berry products. From the berries can be extracted antioxidants and aroma, this refinery process is an established business in some countries and could be a great opportunity for entrepreneurs or people related with the berry business in Sweden. The literature review showed that freeze-drying and microwave-vacuum drying are modern technologies that preserve fruits keeping the majority of them nutrients, freezing and hot air drying are the most common techniques currently used, and osmotic dehydration is an old technique that doesn´t need a big investment and is easy to carry out. The sustainability assessment showed that the main difference between these technologies is in the supply chain and storage stages. In my conclusion, comparing all the technologies I could see that no one is better than the other, rather it depends on the type of product you want to obtain. Also, I could see that one of the biggest challenges to increase the utilization of the wild Swedish berries is find a way to collect them because currently a lot of foreigners are brought to Sweden to collect the berries.