Evaluarea biscuiților și a turtei de orez ca înlocuitori în testarea toleranței orale la glucoză: un studiu de fezabilite pentru studii clinice

Introduction

Worldwide, the prevalence of type 2 diabetes is rising at an alarming rate, with the number of affected individuals projected to increase from 171 million in 2000 to over 366 million by 2030, reflecting a significant global public health challenge⁽¹⁾. This rapid increase is closely linked to the rise in obesity rates, a condition that significantly increases the risk of cardiovascular disease and other health complications, thereby contributing to heightened morbidity and mortality worldwide^(2-4). Type 2 diabetes now affects a diverse demographic, with growing incidence noted not only in high-income regions but across low and middle-income countries, exacerbating healthcare burdens globally.

The standard method for evaluating glucose homeostasis involves an overnight fast followed by the administration of a 75-g oral glucose tolerance test (OGTT) using a liquid glucose beverage, with blood glucose measured two hours post-ingestion. Despite its diagnostic utility, the OGTT presents practical challenges, as the liquid glucose solution is often difficult for patients to ingest on an empty stomach due to its unpleasant taste and high sweetness. These barriers can reduce patient compliance and may compromise test accuracy⁽⁵⁾.

Recognizing these limitations, our study hypothesizes that substituting the traditional OGTT liquid glucose load with a standardized food-based alternative such as biscuits or rice cakes, which deliver an equivalent carbohydrate dose, could provide clinically comparable insights into glucose metabolism while improving patient acceptability and tolerance. Such alternatives could potentially enhance compliance, especially in culturally specific contexts where liquid glucose beverages may not be well accepted, thereby facilitating better diabetes screening and management outcomes. This approach aligns with ongoing global efforts to develop more patient-friendly diagnostic tools without compromising test precision or reliability.

Materials and method

Preparation of test confectionary items

Biscuits were prepared using a standardized formulation of rice flour, sucrose, margarine, egg, baking powder and vanilla essence to deliver a consistent carbohydrate load equivalent to 75 g of anhydrous glucose, as verified by nutritional analysis of two separate batches (250 g total, yielding approximately 45 small biscuits) conducted at the Industrial Technology Institute. Rice cakes were similarly formulated with rice flour, glucose, Astra margarine and eggs, with each average cake weighing 75 g to match the standard OGTT glucose dose. These preparations aimed to replicate the 75-g anhydrous glucose load of the conventional OGTT liquid beverage, which involves fasting patients ingesting a flavored glucose solution followed by 2-hour plasma glucose measurement.

In vitro digestibility assessment

Digestibility was evaluated using a modified enzymatic starch hydrolysis method. Flour samples (0.5 g) were suspended in 15-mL distilled water, treated with 200 µL of α-amylase (2 Mlh, India), and incubated in a boiling water bath (OLS 200, England) at 100°C for 25 minutes. Post-incubation, samples were cooled, transferred to a 50 mL volumetric flask, and diluted to volume with distilled water. Aliquots (1 mL) were then buffered with 2 mL sodium acetate (pH 4.75) and 100 µL amyloglucosidase, incubated at 60°C for 30 minutes with intermittent shaking, cooled and further diluted (1:10) in a 10 mL volumetric flask. Glucose release was quantified colorimetrically: 10 µL sample was mixed with 1 mL of glucose oxidase reagent, incubated at 37°C for 10 minutes in a shaking water bath (Eyela Unithermo Shaker NTS-1300, Japan), and absorbance measured at 500 nm using a double-beam spectrophotometer against a reagent blank. Starch content (%) was calculated as:

We used 100 mg/dL glucose standard, enabling direct comparison to the 100% hydrolyzable glucose in standard OGTT solutions.​

Sensory and storage quality evaluation

Overall quality, color, appearance and taste were assessed hedonically (1 = poor to 9 = excellent) by a panel of six trained confectionary evaluators on sets of five biscuits and rice cakes packaged in aluminum foil and stored for four days. Marketability was rated on a 1-9 scale (1-2 = not marketable, 3 = limited marketability, 4-5 = fair, 6-7 = good with minor defects, 8-9 = excellent), providing comparative palatability data relative to the unpalatable standard OGTT glucose drink.

Statistical analysis

Data were analyzed using one-way ANOVA, with mean separations performed by Duncan’s Multiple Range Test (DMRT) at p=0.05 to determine significant differences in digestibility, sensory attributes, and carbohydrate equivalence between test items and the standard 75-g OGTT glucose benchmark.

Results

The alternative products of rice cake and biscuits for the OGTT test were evaluated for their suitability and digestibility compared to the standard glucose beverage. The digestibility test revealed that the starch content in the fresh food was approximately 50%, translating to about 37.5 g of glucose available from 75 g of rice cake, meaning only two rice cakes are needed to match the 75 g glucose dose in the standard OGTT (Figure 1). In contrast, biscuits required a higher quantity to reach the same glucose dose, which negatively impacted palatability and patient acceptance.

Visually and sensorially, the rice cake exhibited significantly superior color and overall quality compared to biscuits. Both products demonstrated low disease incidence during storage, attributed to effective aluminum foil packaging, which allowed storage without preservatives and extended shelf life. These factors contribute to the rice cake’s practicality as a test item in a clinical setting, likely improving compliance compared to the standard glucose drink which is often poorly tolerated.

Overall, the rice cake emerges as a promising alternative, combining adequate carbohydrate content, favorable digestibility, better sensory qualities and practical storage benefits. This suggests it may offer a more acceptable and stable substitute to the conventional liquid glucose OGTT especially in settings similar to Sri Lanka, where cultural food preferences and logistical limitations exist. Further clinical validation will clarify its diagnostic equivalence and potential for broader implementation.

Discussion

The purpose of this study was to explore the feasibility of a standardized dose of biscuits or rice cake as an effective and well-tolerated alternative to the 75-g glucose beverage for screening women for gestational diabetes. Our findings support the use of the rice cake model, which provides a comparable dose of simple carbohydrates to the traditional glucose beverage. This alternative may offer improved tolerance and acceptability among patients, potentially addressing cultural and palatability challenges in Sri Lanka^(2,3).

Boyd et al. (1995) previously demonstrated that jelly beans could serve as a substitute for gestational diabetes screening, although this approach had not been tested in the Sri Lankan community⁽⁶⁾. Our results extend this concept, showing that a rice cake standardized to deliver an equivalent carbohydrate dose could similarly function as a screening tool for gestational diabetes. Given the local dietary habits and preferences, rice cakes may represent a culturally relevant gold standard for this country’s screening practices.

Conclusions

While this study indicates promise, ongoing research is necessary to optimize the rice cake preparation and ensure it replicates the glycemic response elicited by the 75-g glucose beverage. Future studies will focus on refining dosage and testing in target populations to confirm effectiveness and reliability before widespread adoption in clinical practice. If validated, this approach could facilitate gestational diabetes screening with a more acceptable, practical and potentially cost-effective alternative sugar source, improving patient compliance and outcomes.

Autor corespondent: Faiz M.M.T. Marikar E-mail: faiz@kdu.ac.lk

CONFLICT OF INTEREST: none declared.

FINANCIAL SUPPORT: none declared.

This work is permanently accessible online free of charge and published under the CC-BY.