Assessing the Glycaemic Index of Two Different Cultivars of Date Fruit

Overview

Fruit of the date palm (P. dactylifera) may be considered as an emerging and potential candidate for the development of health-promoting foods, owing to its high nutritional values. Furthermore, aqueous extracts of dates have previously been shown to have potent antioxidant activity, because they inhibit in vitro lipid and protein oxidation and possess free radical scavenging capacity. Although the high sugar content of date fruit has always been a concern, date fruit has been regarded as a low-GI to medium-GI food. However, very limited, inconsistent and contradictory information is available on the glycaemic index values of different date varieties, which may be attributed to both the methodology as well as other food factors. Date consumption is high among people of Arabic origin, where it's very common for them to be eaten with coffee or yoghurt. Therefore, in view of these concerns, the objective of this trial is to evaluate the glycaemic response of two different varieties of dates, named Birhi \& Khassab, in an early maturation stage (Rutab stage), when mixed with 0% fat yogurt, on ten healthy participants aged between 18 and 45.

Introduction Although, the fruit of the date palm (P. dactylifera) may be considered an emerging and potential candidate for the development of health-promoting foods owing to its high nutritive values,the high sugar content of date fruit has always been a concern. Sun-dried dates, which is the well-known ripening stage of date fruit, can be regarded as low-GI to medium-GI food. However, very limited, inconsistent and contradictory information is available on the glycaemic Index values of different date varieties. This variation could be attributed to either the methodology or the food factors. Rational and objective Nowadays, low-GI foods have often been found to induce beneficial effects on risk factors for certain non-communicable chronic diseases . As the chemical composition of dates can vary depending on cultivar, soil conditions, agronomic practices as well as the ripening stage. It is important to know the GI of the local/regional date varieties, and in different date products such as dates with yoghurt. Date consumption is high among people of Arabic origin, where it is very commonly eaten with coffee or yoghurt. During the first trial of this PHD project, treatments containing 150g of 0% fat yoghurt and two different freeze dried date powders, depending on if it was a Birhi treatment or Khassab treatment, were formulated. These were used to assess acute effects of date fruit and yoghurt on mood and cognitive performance in healthy volunteers, as per the ethical approval from Newcastle University. These exact treatments will be used again, and the trial will aim to evaluate their glycaemic index on 10 healthy participants. Participants Ten healthy participants aged between 18 and 45 will be recruited. Participants will be required to undergo a screening visit, followed by three study visits, which will last 2:15 minutes for each visit. Glycaemic indexes will be calculated using standard methods. Results will be calculated using means and standard deviations. Design A standard experimental study involving the measurement of the glycaemic responses of the ingestion of two different varieties of dates, when mixed with 0% fat yoghurt, and a placebo treatment.