Effects of blanching, drying and fermentation on nutrient content and physio-chemical properties of Norwegian Saccharina latissima and Alaria esculenta for application in meat-based products

Abstract

Brown seaweeds are marine macro algae, which are quite unexplored for their potential uses in food products in Europe. Saccharina latissima and Alaria esculenta are fast growing brown seaweeds species in European countries, mainly found in Norway and cold waters of the North Atlantic. These species are known to be rich sources of iodine, protein, polyphenols, carbohydrates and micronutrients like vitamins and minerals. This study aimed to evaluate different treatments of blanching, drying and fermentation on the nutrient profile and physiochemical characteristics of Saccharina latissima and Alaria esculenta. The study also aimed at presenting a preliminary formulation of ‘hamburger patty’ with the best treatment-outcome in terms of iodine reduction. The brown seaweeds contain high concentrations of iodine and can cause adverse effects to thyroid glands, if taken in excessive amounts, thus limiting its use in commercial products.

Different blanching conditions were used (40°C and 95°C at 5m and 10m) as well as drying treatments (oven drying-70°C and freeze-drying) on both seaweed species, afterwards the nutrient profile (iodine, protein and total polyphenol content), along with physiochemical profile (swelling capacity, water holding capacity and oil holding capacity) were evaluated. As part of second study, lactic fermentation was conducted using blanched Saccharina latissima as substrate and Lactobacillus plantarum 299v® as starter culture and changes in iodine and total polyphenol content upon fermentation of Saccharina latissima were evaluated. Lastly, a preliminary formulation of ‘hamburger patty’ was developed based on meat, oat flour and seaweed (best outcome in terms of iodine reduction). The prototype hamburger patties compared with a reference sample based on meat and evaluated for its acceptance by a hedonic test.

The results of blanching and drying treatments on nutrient composition revealed that there was significant difference (p<0.05) with the blanching processes between Saccharina latissima and Alaria esculenta. Oven dried Saccharina latissima (blanched at 95°C-5 mins) was found to attain more reduction of iodine than Alaria esculenta and showed positive influence on physiological properties which are beneficial for product development. Significant differences in iodine content (p<0.05) were found between the untreated seaweed sample when compared with blanched oven dried and blanched freeze dried seaweed samples. Blanching seaweeds at high temperature (95°C) provided best results for iodine reduction (by 60%). The total polyphenol content was found to decrease (by 66%) with blanching and drying treatments in all samples, while protein content somehow increased by 40% with increasing blanching temperatures and time.

Lactic fermentation was conducted in blanched (95°C-5 minutes) Saccharina latissima and raw-untreated seaweed, the results showed gradual decrease in pH for fermented blanched seaweed and raw-untreated samples 5.2 and 4.6 respectively. Consequently, the acidity expressed as lactic acid (%) also increased in both samples. The total phenolic content was found to increase after fermentation by 50% (raw-untreated seaweed) and by 60% (blanched seaweed), while iodine content was found to decrease 12.9% and 38.3% respectively in both fermentations when compared to untreated initial Saccharina latissima. Fermentation of blanched Saccharina latissima can be opted as a method to reduce iodine, increase total polyphenol content, and can be considered for future product development.

In this project the sample, blanched at 95°C-5 minutes and dried at 70°C-100 minutes, was selected for the formulation of burger patty which was compared to a reference burger patty in a sensory evaluation. The results from sensory evaluation showed that samples with seaweed were found to be acceptable, although there is still room for improvements in color, aroma and texture. Moreover, the seaweed samples were found to be more juicy and soft during texture analysis. After the conducted experiments during the study, Saccharina latissima blanched at 95°C-5 minutes was found as a healthier, economical and sustainable alternative to develop a hamburger patty.

Popular Abstract

The demand for vegan products is growing as a reaction to the increased appreciation to health and environmental sustainability. In accordance, this project aimed to explore potential uses of two brown seaweed species widely found in Europe, Saccharina latissima and Alaria esculenta which are known for being rich sources of iodine, protein, polysaccharides and micronutrients like vitamins and antioxidants. The high iodine content limits the use of brown seaweed. Therefore, this thesis also focused to reduce iodine to formulate a safe consumable product.
The project was designed in three different stages to compare the effect of blanching and drying treatments between two seaweed species and use the best possible outcome in terms of iodine reduction for further analysis processes and product formulation. The project firstly focused on studying the changes caused by blanching (40°C and 95°C at 5m and 10m) and drying treatments (oven-drying-70°C and freeze-drying) on nutrient profile (iodine, protein and total polyphenol content), along with physiochemical profile (swelling capacity, water holding capacity and oil holding capacity). Secondly, nutritional changes during fermentation were investigated in one of the seaweed species. Lastly, a preliminary formulation of ‘hamburger patty’ containing pre-treated seaweed, was prepared and assessed for its acceptability in a sensory analysis.
Saccharina latissima (blanched at 95°C at 5m, oven-dried-70°C) was found to be very effective to reduce iodine concentrations. Blanching treatment on seaweeds was found to enhance good physiological properties which are beneficial for product formulation. Fermentation on Saccharina latissima assisted with lactobacillus bacteria was found to reduce iodine and increased total polyphenol content. Preliminary formulation of hamburger patty samples were made with two variations in seaweed content (>15% and <15%), meat, oat flour, salt and pepper. According to the results of sensory analysis, the seaweed flavor in the hamburger patty was acceptable and, overall participants reported to accept the flavour of seaweed and there were some suggestions to improve the aroma.
Using blanched and oven-dried Saccharina latissima can be a novel, convenient and healthy alternative to reduce meat in the diet and can help to generate nutritive, value added food product. The blanching treatment can help to retain nutrient profile, while oven-drying can be beneficial sustainable alternative to store and use seaweed in a commercialized product. The results of fermentation on seaweeds, opens a complete new space and possibility of further research. The amount of protein calculated from the preliminary formulation was about 30% (in dry basis) (contributed from seaweed, oat flour and meat-mix), therefore, it can serve as a more sustainable hamburger patty, with additional nutritional benefits of seaweeds.

• author: Vasavada, Shubha Kirankumar
• supervisor: Claudia Lazarte
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLGM01 20191
• year: 2019
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Food technology, Livsmedelsteknologi
• language: English
• id: 8993294
• date added to LUP: 2019-09-12 14:27:34
• date last changed: 2019-09-12 14:27:34