Glycemic Evaluation of Okra Seed Noodles

Research has confirmed that a food's glycemic effect cannot be accurately predicted from the type and amount of carbohydrates it contains, as the rate at which the carbohydrates is digested and released into the bloodstream is influenced by many factors such as the food's physical form, its fat, protein and fibre content, and the chemical structure of its carbohydrates. For these reasons, it is possible to produce food from the same group with different effects on blood glucose. Consumption of low glycemic index (GI) food has shown to improve glycemic control, lipid profile and reduce systemic inflammation. However, there are few dietary intervention studies attempting to change the GI of food by changing the staple carbohydrates. In this study, the glycemic index of noodle fortified with Okra seed extract will be determined as compared to a control without the fortification. The fortified noodles have been previously tested to produce lower glycaemic response than noodle without fortification. With noodles being one of the staples to many Singaporeans, noodles fortified with functional ingredients derived from food sources offer a lower GI alternative to the conventional noodles without affecting the people dietary preference.

In the investigator's preliminary study, okra exhibits potential as an anti-diabetic food ingredient in the formulation of low GI staple foods. Indian okra was the most effective overall starch hydrolase inhibitor, inhibiting α-amylase with 50 percent inhibitory concentration (IC50) 2.94 + 0.70 μg/mL and α-glucosidase with IC50 of 23.98 + 1.88 μg/mL. Incorporation of okra seeds into tapioca starch, and rice flour noodles successfully lowered digestibility. To verify in vitro results, human clinical trials is proposed to investigate whether okra seed fortification in noodles successfully retards postprandial hyperglycaemia in humans when consumed.

Inclusion criteria

• Ability to give informed consent
• Chinese male/female age between 21-65 years old
• Healthy as determined by medical history, physical examination and laboratory results within normal reference range for the population or investigator site, or results with acceptable deviations that are judged to be not clinically significant by the investigator
• Males and females with stable medical problems that, in the investigator's opinion, will not significantly alter the performance of the biomarker panel, will not place the subject at increased risk by participating in the study, and will not interfere with interpretation of the data.
• Not on any regular medications (western / traditional medicine). Nutritional supplements with established chemical composition that can be ascertained and clearly recorded is acceptable.

However, subjects using traditional medicine (with compositions that cannot be ascertained) will be excluded in this study.

• Have venous access sufficient to allow for blood sampling as per the protocol
• Reliable and willing to make themselves available for the duration of the study and are willing to follow study procedures
• Body mass index of 18 to 25 kg/m2 (male) or 18 to 23 kg/m2 (female).

Exclusion criteria

• History or presence of current cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematological, malignancy or neurological disorders capable of significantly altering the performance of the biomarker panel; or of interfering with the interpretation of data
• Known or ongoing psychiatric disorders within 3 years
• Regularly use known drugs of abuse within 3 years
• Women who are pregnant or lactating
• Have donated blood of more than 500 mL within 4 weeks of study enrolment
• Have an average weekly alcohol intake that exceeds 21 units per week (males) and 14 units per week (females):

• 1 unit = 12 oz or 360 mL of beer;
• 5 oz or 150 mL of wine;
• 1.5 oz or 45 mL of distilled spirits
• Uncontrolled hypertension (blood pressure >160/100mmHg)
• Active infection requiring systemic antiviral or antimicrobial therapy that will not be completed prior to Study Day 1
• Treatment with any investigational drug, or biological agent within one (1) month of screening or plans to enter into an investigational drug/ biological agent study during the duration of this study
• Known allergy to insulin
• History of bleeding diathesis or coagulopathy
• Any of the following laboratory values at screening:

Fasting glucose >=126mg/dL(>=7mmol/L) or 2 hour post-prandial glucose >=200mg/dL (>=11.1mmol/L)

• Clinically significant (as determined by investigator) abnormalities on laboratory examination that will increase risk to the patient or interfere with data integrity
• Have any other conditions, which, in the opinion of the Investigator would make the subject unsuitable for inclusion, or could interfere with the subject participating in or completing the study
• Significant change in weight (+/- 5%) during the past month
• Known allergy to test food or ingredients used in preparation of test food.
• Subjects with electrical implants/devices such as pacemaker.