Are commercial seaweed products able to affect
carbohydrate digestion?
Umamaheshweri Aruchunan (150681788), Dr. Iain Brownlee
BSc Food and Human Nutrition (NUIS), Singapore
1. Introduction
4. Results
2. Aims
• Conduct carbohydrate digestion assays on α-amylase activity; upon α-amylase reaction
with seaweed extracts.
• Evaluate the association between seaweed product processing techniques and
carbohydrate digestibility
3. Materials and Methods
• Analysis for each seaweed extract (labelled : 1 - 14) and control was replicated 8 times.
• Results are presented as mean ± standard deviation of α-amylase activity.
• Mean α-amylase activity was statistically significant (p < 0.05) unless indicated by (*).
131.87
140.00
% α-amylase activity
• Novel treatment aimed at decreasing carbohydrate digestion and subsequently blood
sugar levels, is in demand for diabetic patients [1].
• Seaweeds are large marine algae; commonly consumed in most Asian countries.
• Certain species of seaweed have the potential to hinder the enzyme (α-amylase);
responsible for the digestion of carbohydrate [1].
• It is hypothesized that seaweed products that undergo food processing, loses the ability
to decrease carbohydrate digestion.
117.84
112.59
114.12
112.59
120.00
105.02
100.00
98.43*
93.25
100.00
108.94
98.98*
91.91
91.84
80.00
107.26
94.52
60.00
40.00
Extraction of 14 seaweed products (10 mg/ml)
• Extraction was conducted to release bioactive molecules into the buffer solution (i.e;
seaweed extract)
20.00
0.00
control
Conduct reaction between α-amylase + seaweed extract
• Reaction between α-amylase and seaweed extract was conducted to allow possible
bioactive molecules in seaweed to bind and affect α-amylase activity
Conduct reaction between potato starch and α-amylase + seaweed extract
• Potato starch was added to α-amylase and seaweed extract to allow the digestion
between unbound α-amylase and potato starch.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Seaweed extracts
Based on the bioactivity of 10 mg/ml seaweed product :
• 8 out of 14 seaweed products showed more than 100 % α-amylase activity
• 6 out of 14 products showed less than 100 % α-amylase activity
• More commercial seaweed products boost carbohydrate digestion rather than reduce
carbohydrate digestion.
5. Discussion
Analysis of α-amylase activity
• A visualizing reagent was added to the reaction mix to quantify the extend of starch
digestion. The analysis of starch digestion was optimized to produce more constant
results for each seaweed sample.
• Seaweed products used in this experiment were subjected to heat treatment during
processing (i.e. roasted, grilled or dried).
• Heat treatment could effect structural changes in seaweed products[2].
• This may alter the bioactivity of processed seaweed products which could have resulted
in an increased digestion of carbohydrates.
6. Conclusion
The results suggest that most commercial seaweed products boost carbohydrate digestion. Commercial seaweed products may undergo structural changes during food processing
which could in turn result in an altered biological activity compared to raw seaweed products.
Reference
[1] Balasubramaniam, V., Mustar, S., Mustafa Khalid, N., Abd Rashed, A., Mohd Noh, M., Wilcox, M., Chater, P., Brownlee, I. and Pearson, J. (2013). Inhibitory activities of three Malaysian edible seaweeds on lipase and α-amylase. Journal of Applied Phycology, 25(5), pp.1405-1412.
[2]. Rhein-Knudsen, N., Ale, M. T., & Meyer, A. S. (2015). Seaweed Hydrocolloid Production: An Update on Enzyme Assisted Extraction and Modification Technologies. Marine Drugs, 13(6), 3340–3359. http://doi.org/10.3390/md13063340