Acceptability trial of a novel RUTF based on soy, lentils and rice

By Filippo Dibari, Valid International

Filippo Dibari studied Food Science and Technology and more recently Public Health Nutrition at the London School of Hygiene Tropical Medicine. After four years in the Amazon working with poor farmers and doing research with local universities, he then worked for the UN and for international NGOs in Africa, Latin America and Asia. With Valid International since 2005, he develops and clinically trials novel ready-to-use foods.

This study was conducted under the supervision of Anne Walsh (Valid International) in partnership with Renuka Jayatissa (Medical Research Institute, Colombo) and in collaboration with Moazzem Hossain and Diane Stevens (UNICEF Sri Lanka). The author acknowledges the support of the field coordinator Ngetich Weldon (Valid International), local support from Mrs Sunanda (Sujan Ltd, Colombo) and Brother Rajen (Lasallian C.E.S.S., Colombo) and desk officer support from Samantha Owen and Laura Banks (Valid International). The study was funded by Concern Worldwide and Valid International

This article shares the preliminary results of an exploratory trial of a ready-to-use therapeutic food based on soy, lentils and rice, produced in Sri Lanka.

This article¹ details the preliminary findings of an exploratory study by Valid International that compared the acceptability of a new ready-to-use therapeutic food (RUTF), against equivalent products (Plumpy'nut® and BP100) currently produced in Europe. The new RUTF comprises soy/lentil/rice' (from here onwards called SLR-RUTF), and was produced in Sri Lanka using local facilities and ingredients. SLRRUTF matches the UN 2007² nutritional guidelines for the RUTF macronutrients. The study also compared some acceptability elements of BP100 with Plumpy'nut®.

Method

Dehulled rice, lentils and soya beans

Thirty children aged between three and five years old from three different schools in a Colombo slum (total n=90) were recruited to the study. The trial adopted a crossover design and was split into three phases. Each child consumed one of the three products (Plumpy'nut® (control), BP100, SLR-RUTF) once a day, five days a week, for two weeks. This was done under the direct observation of the research staff members and with the aid of the children's caregivers.

Quantitative data (food intake and clinical aspects) and qualitative information (through focus groups and hedonistic sensory scales) were collected to judge three main acceptability criteria that were established:

1. At least 75% of the children eat more than 75% of SLR-RUTF offered, within 1 hour (meal acceptance).
2. Energy consumption not less than 75% of the energy intake (kcal/kg/day) from the control food (energy intake).
3. Frequency of ill-effects associated with the two products requiring withdrawal from the trial <10% (ill-effects).

MRI official visit to the study site

A simple taste-test (n=10 children) took place a few days before the acceptability trial in order to choose between two possible SLR-RUTF formulations: one with and one without lentils. The formulation with lentils was chosen. Before undertaking the analysis of the data, it was checked whether a carry-over effect³ could have occurred and biased the results.

Limitations

The sample size partly reflected budget constraints. No statistical cluster analysis was undertaken at this point, when pulling together the results from the three schools. For ethical reasons the trial enrolled non-malnourished children aged 3 to 5 years - acceptability may be different in malnourished children and in younger children. Rates of weight gain are different in nutritional rehabilitation than in normal child growth. Due to the stage of the project design, SLR-RUTF formulation did not contain a premix of vitamins and minerals. Therefore the acceptability of SLR-RUTF with a premix added could differ from the results of this trial.

The time span of this trial to measure acceptability may have been too short. In this study, all the RUTF products were tested for two weeks per child per phase, whereas in a feeding prog - ramme the minimum duration of the nutritional therapy would generally be eight weeks. The study did not account for the amount and nature of food intake for the rest of each child's day.

BP100 was provided as a dry biscuit during the first two days of the trial and then replaced by the porridge form. This was because of low acceptance of BP100 as a biscuit, and also to adhere with what is recommended for use in Sri Lankan refugees' camps settings. Therefore the data from the first two days could not be included in the data base. The comparison of BP100 porridge with SLR-RUTF and Plumpy'nut® does not respect iso-caloric conditions.

A crossover design with three groups should theoretically include six combinations of the three products among the three groups (ABC, ACB, BAC, BCA, CAB, and CBA). This was not done because of the exploratory nature of the trial and its budget constraints. The sequence of products assigned to each group was randomly chosen.

Results

The gender balance of study differed by school with females representing 72%, 50% and 44% for schools A, B and C respectively, and was significantly different between schools A and C, (p=0.04). The number of adults per child household also varied (3.3, 3.5 and 5.7 adults/ household). This difference was significant (p<0.01) between schools A and C, and schools B and C. No carry-over effect was detected (all p-values >0.05).

Meal acceptance

All three products were offered during one of the school breaks that lasted ~1 hour. All the children were offered 500 kcal/92 g of Plumpy'nut®, or 500 kcal/100g of SLR-RUTF, or 500 kcal/310 g of BP100 (in the form of porridge⁴). Any extra amounts requested by the children were recorded and monitored.

The criterion is satisfied because 81% of children ate more than 75% of the offered amount of SLR-RUTF. The SLR-RUTF intake (median: 5.0 g/kg/child/day; IQR 3.5-6.1) of these children was higher (p<0.001) than the amount consumed by 75% of the control food intake (4.2 g/kg/child; IQR 3.0-5.3). For all children, Plumpy'nut® showed a median intake of 5.6 g/kg/child/day (IQR 4.1-7.0).

It was decided that comparison of BP100 (in the form of porridge) with Plumpy'nut® (in the form of paste) is not valid because of the different forms in which the two products were presented.

Energy intake

The data suggest that the median energy intake (25.0 kcal/kg/day; IQR 17.8-30.6) from SLR-RUTF was significantly higher (p=0.04) than 75% of the energy intake from the control food (22.4 kcal/kg/child; IQR 16.4- 28.2). The energy intake from BP100 (34.5 kcal/kg/child; IQR 26.1-42.5) was higher (p=0.02) than the energy intake from Plumpy'nut® (29.9 kcal/kg/child; IQR 26.1- 42.5). Surprisingly BP100 showed a statistically significant (p<0.001) lower weight gain (0.7 g/kg/child⁵; IQR 0.0-2.0) than SLR-RUTF (1.9 g/kg/child; IQR 0.0-2.8), and when compared with Plumpy'nut® (2.1 g/kg/child; IQR 0.8-4.6).

Ill-effects

Any reason for absence/defaulting was carefully investigated. No child withdrew from the trial because of clinical symptoms associated with the ingestion of any of the products. Any sign of illness, fever, vomit, belly pain, flatulence, or itching was recorded daily by supervised direct observation and by carer weekly recall. The statistical analysis of these records demonstrated that there was no relevant difference between the products.

Sensorial analysis

The general pattern was that the caregiver/child preferred Plumpy'nut® to SLR-RUTF in terms of general acceptability (p=0.001), colour (p<0.001), taste (p=0.01), and texture (p=0.03). BP100 was preferred to Plumpy'nut® for colour (p<0.01), and texture (p=0.04). No difference was reported for the level of sweetness (see Table 2).

Consumption trends

The results of the consumption trends seemed to show that intake of SLR-RUTF remained constant, while the intake of Plumpy'nut® increased slightly. BP100 intake increased remarkably over the course of the trial (see Figure 3)

Discussion

Despite the sample size limitations, there seems to be sufficient evidence to consider the new SLR-RUTF product sufficiently acceptable and safe, even if some of its characteristics are still to be improved. Furthermore SLR-RUTF seems to provide a weight gain close to that attributed to Plumpy'nut® and indicatively superior to that of BP100. However, the metabolic conditions of the healthy study children and their expected weight gain are different from those of acutely malnourished children. Also, the study did not account for the food intake for the rest of each child's day.

A pot of soy/lentil/ rice RUTF

In terms of general sensorial analysis, BP100 seems to perform better than SLRRUTF, when compared with Plumpy'nut®. Sugar levels in SLR-RUTF were found by the children to be satisfactory, but colour/ appearance of SLR-RUTF requires further improvement. Since SLR-RUTF will eventually be packaged in opaque multi-layered sachets rather than in the transparent jars used in the study, colour may prove to be less influential in final acceptability tests.

Scores related to taste and texture were also higher for BP100 than SLR-RUTF. The Plumpy'nut® score was particularly high and there could be many reasons for this. For example, the high content of milk powder in Plumpy'nut® (~30%) makes the final product very creamy and extremely appealing. In the case of BP100, the children and the caregiver might have felt more familiar with its appearance and consistency. However no complaints about the 'beany' flavour from soy, one of the main ingredients of SLR-RUTF, were reported.

Conclusions and follow-up

The findings from this study support future randomised controlled clinical trials in South Asian countries affected by severe acute malnutrition (SAM). These should include a more in-depth multivariate analysis (including possible confounding factors). From this study, it appears that the general acceptability of SLR-RUTF, particularly in terms of taste and texture, could be improved. The impact on taste of introducing the vitamin and mineral premix to SLR-RUTF will require careful assessment before initiating the trials.

For more information, contact: Filippo Dibari, email: filippo@validinternational.org.

¹Dibari F, et al. (in review). Development and acceptability of milk-free ready to use therapeutic food (RUTF) based on industrial extrusion cooking process.

²Source: http://www.who.int/child_adolescent_health/documents/a91065/en/index.html.

³A carry-over effect, likely to happen in crossover designs, occurs when the effect of the first product in the first phase carries over to the second phase when providing the second product; and/or when the second product carries over the effect to the third phase when providing the third product.

⁴According to instructions, clean water was added to BP100 tablets in the proportion of 2 dl: 2 tablets (2x28.4 g; 300 kcal). The water was boiled (evaporation: loss ~30%) and mixed to the tablet without further prolonged boiling.

⁵Expressed as: (weight at the end of the phase - weight at the beginning of the phase) / (weight at beginning of the phase x no. of days in the same phase).