Examination of Nopal Cactus Cladodes and its Effect on Postprandial Glycemic Regualtion through a Pilot Meal study on Healthy Volunteers

Abstract

Opuntia ficus-indica is a cactus plant rich in dietary fiber and vitamins. It can be considered as a functional food, and some of its extracted components can be added as functional ingredients to improve postprandial glycemic regulation. The aim of changing our dietary habits by eating such foods is to reduce blood glucose levels after ingesting a starchy
food together with the nopal product, which can decrease the risk of developing type 2
diabetes and cardiovascular disease or help in managing such diseases. The objective of this
study was to examine the effect of Nopal cladodes on postprandial glycemic and insulinemic
response, and also on appetite related variables. Three different batches of Nopal cladode flour
were examined and characterized for their starch and dietary fiber contents. An in-vitro
digestion method (Hydrolysis Index, HI) was performed to mimic the human digestion process
and used to predict the impact of the nopal flour on the glycemic index (GI) with white wheat
bread as a reference. One of the flour batches was then chosen to be included in a pilot meal
study, where the nopal flour was separated into its water soluble and insoluble fractions, which
were used to produce soluble and insoluble fraction-containing breads. Seven healthy
volunteers participated in a randomized pilot study designed to investigate the postprandial
glycemic and insulinemic responses of the test breads. The Nopal flour breads made from the
three different batches had equivalent dietary fiber contents, and Analysis of variance (ANOVA)
results showed that there were no significant differences in HI between the nopal flour breads
and a reference wheat flour bread without nopal flour supplement. Performing a Tukey’s range
test showed a significant difference between two of the batches HI values. Due to the limited
amount available of the flour from the batch with the lowest HI, and thus a low predicted
glycemic response, the human pilot study was performed with the flour with the second lowest
HI. The HI values for the soluble and insoluble fraction breads produced from this batch were
not different and, using ANOVA-repeated measurements, the in vivo glycemic and insulinemic
responses showed no statistical significance either. The appetite variables followed a similar
statistical tendency except for the fullness feeling after eating the nopal bread with added
soluble fraction, as it was higher than the reference bread at 120 min (p=0.0349). Nopal
cladodes flour can partly replace wheat flour to increase the beneficial health effects of bread;
still the mechanisms behind the postprandial glycemic regulation should be further investigated on a larger study population.

Popular Abstract

The risk of developing cardio-metabolic diseases such as type 2 diabetes and cardiovascular diseases is
increasing around the world. These diseases are related to lifestyle habits including diet and physical
activity, meaning it can be avoided and the risks of developing it can be reduced. The inclusion of dietary
fiber in diets is considered to have beneficial effects on the consumer, as it may decrease the blood
sugar levels and potentially reduce the risk of developing type 2 diabetes.
Opuntia ficus-indica or Nopal is a cactus plant rich in dietary fiber and other bioactive compounds such
as ascorbic acid and flavonoids. Nopal originates from Mexico and is commonly grown in deserted
environments around the world. Habitants of Hispanic origins use Nopal cactus as a natural treatment to
control their sugar levels and prevent risks of developing diabetes. The aim of this study was to enrich a
daily food type with dietary fiber-rich nopal flour to determine effects on postprandial blood glucose
levels and insulin responses in healthy volunteers. Examining such a food component can further help in
increasing the nutritional value of our meals and reduce the risks of developing cardio-metabolic
diseases, paving the way for designing foods and diets to achieve health benefits. This study investigated
the effects of the water-soluble and water-insoluble fractions of Nopal cladodes included in bread on
postprandial glycemic responses along with appetite-related variables (hunger, satiety or fullness and
desire to eat) in healthy participants for 2 hours after consumption. Three white wheat flour-based
breads, enriched with nopal flour, were tested in the pilot meal study and the postprandial effects were
compared with white wheat flour bread without nopal flour.
The results from the study showed that there were no detectable differences on the postprandial
glycemic responses when eating the different test breads. The only noticeable difference between the
reference bread and the nopal breads was the time of the peak glucose response. Thus, the three test
breads delayed the postprandial glucose concentration peak. This study also showed that the Nopal
bread containing an extra amount of the water soluble fraction increased the fullness feeling when
compared with the white bread. Thus, this fraction can be included in dietary plans to achieve satiety
and prevent over-eating (e.g.: obesity treatment).Further research on Nopal is required to generate
more results, to be able to categorize nopal as a functional or “healthy food”, and incorporate it in diets
for the prevention of cardio-metabolic diseases.

• author: Sokrat, Omar
• supervisor: Anne Nilsson; Juscelino Tovar
• organization: Food Technology and Nutrition (M.Sc.)
• course: KNLM01 20211
• year: 2021
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Nopal, Cladodes, Dietary fiber, Hydrolysis index, Glycemic response, Appetite variables, Applied nutrition, Food Chemistry
• language: English
• id: 9063164
• date added to LUP: 2021-08-23 13:59:14
• date last changed: 2021-08-23 13:59:14