Ready-to-use therapeutic food (RUTF) and its shelf life analysis.

What is RUTF?

Ready-to-use therapeutic food (Plumpy’nut) was invented in the late 1990s by research scientist André Briend and Nutriset, a private company making nutritional products for humanitarian relief. RUTF is high in energy and protein, with added electrolytes, mineral and vitamins, specifically designed to treat SAM in the rehabilitation phase. It is equivalent to F100 in terms of nutrients/100kcal. It does not have to be mixed with water and so is microbiologically safe and enables treatment in the community.

What is the advantage of using RUTF?

RUTF has significant advantages over liquid based diets. The paste is oil-based with low water activity and, as such, can be stored at home with little risk of microbial contamination. It is easily used at home by mothers and caregivers, and is digestible and popular among sick and malnourished children and adults. RUTF is effective in promoting rapid weight gain in malnourished children.

What is the composition of RUTF?

The most widely used at present is Plumpy’nut. The ingredients are peanut paste, milk powder, vegetable oil, sugar, potassium, magnesium, vitamins, and minerals. Each 92g pack provides 500kcal.

Can RUTF be produced locally?

The high cost of the imported RUTF is a significant barrier to the wide-scale implementation of CTC. To overcome this barrier, the CTC program currently promotes local production of RUTF.

Local production of RUTF has been successful in Malawi. The cost of the local version is about half that of the imported version. The locally produced RUTF follows the same recipe as original Plumpynut and is packed in 250g plastic jars with a shelf life of up to six months. Comparison efficacy studies demonstrate that the locally produced RUTF is nutritionally equivalent to the imported version.

What makes RUTF different from family foods and other feeds fed to severely malnourished children?

·         RUTFs do not need cooking and do not need to be mixed with water.

·         The high fat content and low moisture prevents bacterial growth, which means that they are microbiologically safer than feeds prepared with water. RUTF will keep for several months in simple packaging.

·         Electrolytes and micronutrients are added during production, whereas these need to be provided as supplements when using family foods.

·         RUTFs are usually more expensive than high-energy mixtures of family foods.

There are four basic ingredients in RUTF: Sugar, Dried Skimmed Milk, Oil, Vitamin and Mineral Supplement (CMV) In addition, up to 25% of a product’s weight can come from oil-seeds, groundnuts or cereals like oats.As well as containing the necessary proteins, energy and micronutrients, RUTF should also have the following attributes:                                                 1)Taste and texture suitable for young children; and 2)No need for cooking before consumption
 Resistant to contamination by micro-organisms and long shelf-life without sophisticated packaging. Product should be oil-based

Ready-to-Use Therapeutic Food High energy, fortified ready to eat food suitable for treatment of severely malnourished children. This food should be soft or crushable, palatable and easy for children to eat without any preparation. At least half of the proteins contained in the product should come from milk products. Nutritional composition
Moisture content	2.5% maximum
Energy	520-550 Kcal/100g
Proteins	10 to 12 % total energy
Lipids	45 to 60 % total energy
Sodium	290 mg/100g maximum
Potassium	1100 to 1400 mg/100g
Calcium	300 to 600 mg/100g
Phosphorus (excluding phytate)	300 to 600 mg/100g
Magnesium	80 to 140 mg/100g
Iron	10 to 14 mg/100g
Zinc	11 to 14 mg/100g
Copper	1.4 to 1.8 mg/100g
Selenium	20 to 40 µg
Iodine	70 to 140 µg/100g
Vitamin A	0.8 to 1.1 mg/100g
Vitamin D	15 to 20 µg/100g
Vitamin E	20 mg/100g minimum
Vitamin K	15 to 30 µg/100g
Vitamin B1	0.5 mg/100g minimum
Vitamin B2	1.6 mg/100g minimum
Vitamin C	50 mg/100g minimum
Vitamin B6	0.6 mg/100g minimum
Vitamin B12	1.6 µg/100g minimum
Folic acid	200 µg/100g minimum
Niacin	5 mg/100g minimum
Pantothenic acid	3 mg/100g minimum
Biotin	60 µg/100g minimum
n-6 fatty acids	3% to 10% of total energy
n-3 fatty acids	0.3 to 2.5% of total energy

Commercial Pre-packed Plumpy'Nut

Plumpy’Nut is a ready-to-use therapeutic spread produced by Nutriset and presented in individual sachets. It is a paste of groundnut composed of vegetable fat, peanut butter, skimmed milk powder, lactoserum, maltodextrin, sugar, mineral and vitamin complex.

Plumpy’Nut is specifically designed to treat acute malnutrition without complications and has the following characteristics:

·         It is nutritionally equivalent to F-100 (therapeutic milk used for in-patient care in Phase 2)
 

·         One sachet has an energy value of 500Kcal
 

·         One sachet has a weight of 92 g
 

·         Each carton of Plumpy'Nut contains 150 sachets (around 15.1 kg)

 Benefits and composition of Plumpy'Nut

·         The quantity distributed to each child is easy to calculate based on the weight
 

·         One simply needs to open the sachet by cutting one corner and eat the paste
 

·         No preparation or cooking is necessary
 

·         Does not need to be diluted with water. This eliminates risk of contamination
 

·         Can be used at home with supervision from the health centre
 

·         Reduces length of stay in hospital or Therapeutic Feeding Centre
 

·         Reduces number of staff necessary for preparation and distribution of therapeutic food
 

·         Has a faster recovery rate and higher acceptability than F100
 

·         Can be stored at room temperature for long periods of time
 

·         Has a long shelf life, even without refrigeration (24 months)

Quality Control

Choice if ingredients: Whichever the scale of production is used, quality control is achieved by safe storage of the ingredients, adequate training and supervision of the production personal, and product testing for composition and contaminants. Throughout the world, authorities set standards for food production companies; those organizations involved in RUTF production should adhere to these standards. Key issues in quality control are listed as follows.

Aflatoxin contamination: This toxin is produced by an aspergillus species of fungus, which contaminates the peanuts after they have been harvested, but before they have been ground into peanut butter. The fungus is ubiquitous, fungal growth can be curtailed by storing the peanuts in a cool, dry environment, and can also be controlled using chemical fungicides. Methods to prevent aflatoxin contamination have been described in detail elsewhere. Peanuts should be purchased from a supplier that can ensure that steps to prevent contamination have been implemented during harvest and storage. Aflatoxin contamination is more likely to be seen in peanuts with black discoloration, and among nuts that have a shriveled, irregular appearance. Consumption of aflatoxin can result in hepatic oxidative stress, and predispose the individual to hepatic cancers. RUTF should conform to international standards for maximum aflatoxin content, 10-20 ppb. Very high doses of aflatoxin can produce acute intoxications. Moderate doses may depress child growth.

Bacterial contamination: The inherent microbiological safety of RUTF allows it to be packaged under clean and dry, but not sterile, conditions. Care must be taken to prevent the introduction of water into RUTF during production. Increasing the water content of RUTF allows bacteria and mold to grow within the food, promoting product degradation and exposing the malnourished child to potential pathogens. Water is most likely to be introduced from residue left on the mixing bowls and containers after they have been washed. Therefore, it is better to limit the number of times the implements of production are cleaned with soap and water, and to simply dry wipe them clean instead. Typically implements need to be cleaned with soap and water only once a week. If the containers in which the RUTF is to be dispensed are first washed, care should be taken to see that they are completely dry. Enteric bacterial contamination is most likely to occur from fecal contamination of stored ingredients or during the mixing process. Care should be taken to store in ingredients in areas which are free of rodents. Workers should wash and thoroughly dry their hands before manipulating the RUTF, wear clean plastic gloves, hair coverings and protective coats during RUTF production. Milk and RUTF should be periodically checked for salmonella contamination by standard microbiological methods in reliable laboratories.

Prevention of oxidation: Oxidation of the fatty acids contained in the RUTF and of some vitamins, mainly vitamin A and C, is the main factor limiting the storage life of RUTF. During the production, some preventive measures should be taken to avoid initiating the oxidation process. While it is helpful to heat the oils during the mixing process to achieve a homogenous mixture, heating to temperatures over 45ºC accelerates the oxidation of the lipids, which reduces the period of time that the product is stable after production (shelf life). To prevent oxidation, it is also better to use airtight containers and containers filled as much as possible so that the quantity of oxygen within the container is minimized. The shelf life of locally produced RUTF without airtight packaging is 3-4 months. When RUTF is packaged in airtight foil envelopes under a nitrogen atmosphere (devoid of oxygen), the shelf life can be extended to 24 months.

Composition of RUTF: Errors may be made during the mixing process, which result in RUTF that has a substantially different nutrient content. These are best avoided by careful training of workers mixing the food, use of convenient measures of ingredients for batches of RUTF and periodic compositional testing of RUTF. Measuring a single mineral, such as potassium, by atomic absorption is an inexpensive, reliable way to monitor the vitamin/ mineral content, since the minerals are added as a premix product. If an atomic absorption spectrophotometer is not available, a colorimetric assay for Vitamin C can be substituted. Measuring fat and protein content assure that the other ingredients are being added in appropriate amounts.

Quality control is achieved by adopting operating procedures that are internationally accepted as

standards for food production, the Codex Alimentarius and the Hazard Analysis and Critical Control Point Program (HACCP). These procedures prescribe raw material procurement, storage of ingredients, mixing of ingredients and storage of finished product. In addition to international standards, every nation of the world has a Bureau of Standards which regulates the production of food. These Bureaus also prescribe operating standards, conduct inspections of factories and issue licenses to produce food. Product testing is used to verify the quality of the production process, and should be done with every large batch of finished product, certainly every week. In Malawi, finished product is tested weekly for contaminating microbes (salmonella, staphylococcus, total flora of aerobic mesophilic bacteria, coliforms, E. Coli, yeast, mold), aflatoxin and product composition (fat, protein and potassium). Testing is best done locally so that it can be used to identify lapses in production quality in a timely manner.

Batches of RUTF should not be sent to consumers without verification of product quality. Almost every nation of the world has a laboratory associated with their Bureau of Standards that can conduct the independent testing.

Real Time vs. Accelerated Shelf Life Studies There are two basic methods for performing shelf life studies: Real Time and Accelerated. Real time studies store the product under the normal conditions of the product for a period of time greater than the expected shelf life. The product is checked at regular intervals to determine the point of product deterioration. Accelerated shelf life studies attempt to predict the shelf life of a product without running a full length storage trial. This type of study is usually used for product with a longer shelf life. Acceleration factors such as temperature are applied to the product to attempt to increase the rate of deterioration. The data can be used in predictive mathematical models to project spoilage rates and bacterial growth. Accelerated studies should be used with caution, you must know a good deal about your specific product formulation and properties to interpret the data optimally.

It is always recommended that when an Accelerated study is selected that a dual, real-time study is also run concurrently to validate the projected data.

7 Steps to Determine Shelf Life

1. Identify what may cause the food to spoil
• Product: raw materials, formulation, water activity, pH, oxygen availability, preservatives
• Process: Processing activities, packaging, storage conditions
2. Decide which tests to use
• Sensory: odor, appearance, flavor texture
• Microbiological: spoilage and pathogenic organisms
• Chemical: pH, free fatty acids, headspace analysis, etc.
• Physical: product abuse storage and handling
3. Plan the shelf-life requirements
• What tests need to be done
• How long will the studies be run
• How many samples for each test
• How many samples for the entire study
• What are the storage conditions
• When will the study be run
4. Run the Shelf Life study
• At time intervals established in step 3.
• Run the appropriate tests in step 2
5. Determine the shelf life
• Eventually a point is reached when the product no longer meets requirements for quality or safety, which is the shelf life
• Usually a pre determined point is established to end the study if quality and safety are not affected
6. Establish working shelf life
• Working shelf life will be less than actual shelf life due to real world factors such as storage conditions and potential product abuse
7. Once product is released to the market -> Monitor Shelf Life
• Investigate any customer complaints or failures
• Evaluate samples from production and distribution to validate study results.