NOTE: End date changed to 10/31/2017 per G. Douglas/JSC (Ed., 12/14/15)

NOTE: Changed from NSBRI to NASA-monitored project, per M. Perchonok/NASA JSC (Ed., 2/25/2013)

Vitamin levels in relatively low and high fat content compressed bars and dispersed drink mixes, fortified with twice the Space Flight Requirement for vitamins A, B1, B9, C, and E, were analyzed after three years storage at 70F. Vitamins in relatively low fat products had been encapsulated in a lipophilic coating; vitamins in relatively high fat products had been encapsulated in a starch-based coating. Vitamin contents were measured by Covance Co., with n=6.

Losses for the vitamins after 3 years storage at 70F are as follows.

Vitamin A: low and high fat bars—15 % (both); low and high fat beverage bases—17% and 16%, respectively.

Vitamin B1: low and high fat bars—23% and 8.5%, respectively; low and high fat beverage bases—4.8 and 23%, respectively.

Vitamin B9: low and high fat bars—26% and 21%, respectively; low and high fat beverage bases—30% and 26%, respectively.

Vitamin C: low and high fat bars—11% and 5.7%, respectively; low and high fat beverage bases—4.8% and 7.4%, respectively.

Vitamin E: low and high fat bars—4.9% and 3.7%, respectively; low and high fat beverage bases—4.6% and 8.4%, respectively.

Results show that vitamin loss susceptibility after 3 years storage, on average, followed the sequence, B9 > A > B1 > C > E.

Overall effects of product form (i.e., compressed bars vs. powders) and of relative product fat level were calculated using paired two-sample T-test comparisons of pooled data, with populations of 60 values/replicates in each data set. In general, percent losses were higher (~25%) in the dispersed particulate beverage bases, with moderate statistical significance. Compacted bars may be slightly more stable against oxidation-induced degradation of vitamins due to inhibited contact of packaging-entrained oxygen with the interior of the products. While, on average, lower fat products exhibited slightly less (~12%) vitamin degradation than did high fat products, this effect had low statistical significance.

Testing of pouches and food product at time 0, 3, and 6 months at 100F and time 0 and 6 months at 70F has been completed. Samples have also been pulled for 1 year at 100 and 70F, and testing of food and package is currently underway. Testing of food components included sensory, vitamin, color, and water activity analysis. Package testing included barrier, seal strength, mechanical, and burst testing. Prior to package testing, food product was emptied from pouches and pouches were cleaned with soapy water and dried. Sample identification for package testing is as follows: (1) the control sample is the unfilled and unprocessed pouch, (2) t=0 samples represent pouch data immediately after processing, (3) t=3 months and t=6 months indicates samples that were pulled at the respective time intervals. Pouch integrity testing shows that Pouch B/retort undergoes a 10-14% decrease in seal strength after processing (t=0); however, seal strength begins to slightly increase after storage at 100F. Pouch A (MATS/retort/irradiation) shows a slight increase in seal strength going from control (unprocessed pouch) to t=0 (after processing), then drops back down to a value close to the control value at 3 months (100F) and 6 months (70F), before increasing to maximum value at 6 months (100F).

ED. NOTE (June 2021): Project continues with Principal Investigator (PI) Danielle Froio-Blumsack continuing work initiated with PI Dr. Ann Barrett, whose work covered the first 3 years of this contract with U.S. Army. See "Stabilized Foods for Use in Extended Spaceflight: Preservation of Shelf-Life, Nutrient Content and Acceptability (Froio-Blumsack)" for subsequent reporting.

NOTE: End date changed to 10/31/2017 per G. Douglas/JSC (Ed., 12/14/15)

NOTE: Changed from NSBRI to NASA-monitored project, per M. Perchonok/NASA JSC (Ed., 2/25/2013)

Effort 1 (Matrix Effects)

VITAMIN LOSSES AFTER 2 YEARS AT 70F

Vitamin levels in relatively low and high fat content compressed bars and dispersed drink mixes, fortified with twice the Space Flight Requirement for vitamins A, B1, B9, C, and E, were analyzed after two years storage at 70F. Vitamins in relatively low fat products had been encapsulated in a lipophilic coating; Vitamins in relatively high fat products had been encapsulated in a starch-based coating. Vitamin contents were measured by Covance Co., with n=6.

Losses for the vitamins after 2 years storage at 70F are as follows. Vitamin A: low fat and high fat bars—18%: low fat beverage base—24%; high fat beverage base—22%; Vitamin B1: low fat bar—2%; high fat bar—3%; low fat beverage base—1%; high fat beverage base—25%; Vitamin B9: low fat bar—5%; high fat bar—3%; low fat beverage base—35%; high fat beverage base—49%; Vitamin C: low fat bar—9%; high fat bar—2%; low fat beverage base—8%; high fat beverage base—0%; Vitamin E: low fat bar—0%; high fat bar—3%; low fat beverage base—3%; high fat beverage base—1%. Results show that vitamin loss susceptibility after 2 years storage, on average, followed the sequence, B9 > A > B1 > C > E. Vitamins, on average,were more stable in compressed bars (which were vacuum packed) rather than in dispersed beverage bases, especially for vitamin B9/folic acid.

KINETIC ANALYSIS OF VITAMIN DEGRADATION IN NASA PRODUCTS: Kinetic analysis of vitamin losses in the fortified foods, using all pulls to date and data from both high and low temperature storage (70F: 1 and 2 year pulls, and 100F: 6 month and 1 year pulls), was completed. Vitamin levels at the endpoint storage times were first statistically tested for differences from Time 0 levels by a two sample t-test. Vitamins/systems showing significant degradation at p < 0.05 were then fitted to the first order kinetic equation, [ln(C/Co) = -kt], where C and Co are vitamin content at storage time t (in months) and vitamin content at time zero, respectively, and k is the degradation rate constant (in reciprocal months). Vitamins exhibiting appreciable degradation (i.e., exhibiting rate constants greater than 0.004 month-1) were: A, in all systems; B1, in the high fat beverage and in the low fat bar (high temperature only); B9, in both beverages and in the low fat bar (high temperature only); and C, in the low fat bar and in all products stored at high temperatures. Vitamin E had no discernible loss in any system.

Data for Vitamin A, for which rate constants for both products at both temperatures were above the 0.004 month-1 threshold, were furthermore fitted to the Arrhenius model, [ln(k2/k1) = Ea/R[(1/T1)-(1/T2)], in which the constant R is in (J/mol-Ko), T is temperature (Ko), subscripts 1 and 2 respectively refer to low and high storage temperatures, and Ea is activation energy (J/mol). A relatively higher activation energy indicates relatively greater dependence of degradation rate on temperature. Vitamin A demonstrated an appreciable temperature sensitivity, with Ea >50 KJ/mol in both bars and beverages; reaction rate was increased by a factor of 2-3 by a temperature increase of 30o.

Effort 2 (Processing/Packaging Effects)

The objective of this effort is to investigate innovative multilayer packaging materials for compatibility with novel food sterilization methods and assess food quality as a function of processing method and package type. In this effort food processing methods including Microwave Assisted Thermal Sterilization (MATS), Irradiation, and Retort were studied to determine the effect on a down-selected non-foil pouch utilizing a novel high barrier coating technology and a control aluminum foil (AF) Retort Pouch. The pouches were filled with Creamy Cajun Chicken, and subjected to the various processing methods. Pre- and post-processing pouch integrity was analyzed. During FY16, mechanical, bust, and barrier testing were conducted on the packaging materials, and water activity, color analysis, and sensory acceptance were used to evaluate the food. Previous years’ research led to the down-selection of 3 pouch/processing combinations based on mechanical integrity, barrier performance, seal strength, layer analysis, and sensory data. The down-selected pouch/process combinations include (1) Pouch A/MATS, (2) Pouch A/Irradiated, (3) Pouch A/Retort, and (4) Pouch B/Retort. Pouch A employs an aluminum oxide coated film, and Pouch B is the control aluminum foil based Retort Pouch. The second phase of a contract with Ameriqual was executed during FY16, which included processing of the down-selected pouch/process combinations mentioned above, with Creamy Cajun Chicken. A total of 2000 pouches were produced and processed. All samples passed microbiological testing, indicating that the processing methods were successful in achieving commercial sterilization. Pouches were received by NSRDEC and inspected prior to being placed into short term (12 months @100F) and long term (36 months @70F) storage.

Testing of pouches and food product at time zero and 3 months at 100F has been completed. Pouch integrity testing shows that Pouch B/retort shows a 10-14% decrease in seal strength after processing, whereas Pouch A shows no change in seal strength after processing or 3 month storage at 100F. Burst testing showed no change in burst strength for Pouch A; however, burst data could not be collected for Pouch B, as it exceeded the maximum pressure limits of the equipment. Modulus of the pouches decreases by approximately 30% after processing for all pouches except Pouch A/Irradiated. However, Pouch A/Irradiated does show a drop in modulus of 37% after 3 months storage. Barrier testing is currently ongoing, but initial data shows that water vapor transmission rate (WVTR) is comparable to results obtained in the first down-selection phase of the project, where minimal changes in WVTR were observed before and after processing.

With respect to changes in the food product, water activity, color analysis, and sensory analysis were performed. There is decrease in water activity for food packaged in Pouch A, between time zero and 3 months at 100F. The decrease is small, but a consistent trend is seen for all Pouch A samples. Pouch B shows consistent water activity readings for time zero and 3 months. Color analysis showed minor darkening/yellowing of the Pouch A/Irradiated samples after 3 months at 100F. This sample was the lightest and least yellow initially, and is still considerably lighter than the other samples. Sensory analysis reveals a significant difference in Appearance Quality at time zero, with Pouch A/Irradiated having scores of 6.23 and all other samples having scores in the range of 5.44-5.83, with Pouch A/Retort scoring the lowest. Sensory data at 3 months indicated a significant difference in Flavor Quality, with Pouch A/Irradiated showing the lowest score for flavor of 5.42, and Pouch A/Retort showing the highest score of 6.09. Vitamin analysis of vitamins A (retinol), C (ascorbic), E (a-tocopherol), B1 (thiamin), and B9 (folic acid) is currently underway at Covance.

NOTE: Changed from NSBRI to NASA-monitored project, per M. Perchonok/NASA JSC (Ed., 2/25/2013)

EFFORT 2: Processing and packaging research. The objective of this effort is to investigate innovative multilayer packaging materials for compatibility with novel food sterilization methods and assess food quality as a function of processing method and package type. In this effort various food processing methods, such as Microwave Assisted Thermal Sterilization (MATS), Pressure Assisted Thermal Sterilization (PATS), Irradiation, and Retort were studied to determine the effect on pouches utilizing three different and novel high barrier coating technologies and a control aluminum foil (AF) Retort Pouch. The pouches were filled with Creamy Cajun Chicken, and subjected to the various processing methods. Pre- and post-processing pouch integrity was analyzed. During FY15, barrier testing, layer analysis, sensory acceptance, and vitamin analysis were completed for Effort 2. Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) were tested before and after processing using a MOCON® Ox-Tran 2/21 and a MOCON® PermaTran 3/31 following ASTM D3985 and F1249, respectively. Measurements were taken at 23ºC and 50% RH and 37.8ºC and 90% RH, for OTR and WVTR, respectively. Optical microscopy was employed to conduct layer analysis, and utilized a Nikon Microscope and DXM1200 Digital Camera at 20x magnifications. Film cross-sections were analyzed with and without an iodine staining technique, which allows for easier detection of nylon layers within the film structure. Twelve-member trained technical panels evaluated sensory appearance, odor, flavor, texture and overall quality of the Creamy Cajun Chicken, using a 9-point hedonic scale and Sensory Information Management System (SIMS) acquisition/processing of data. Vitamin analysis of vitamins A (retinol), C (ascorbic), E (a-tocopherol), B1 (thiamin), and B9 (folic acid) was conducted by Covance using Nutritional Labeling and Education Act (NLEA) nutrient sample analysis. Six replicates of each sample were tested.

Barrier testing shows that of the test pouches, Pouch B (Toppan aluminum oxide coating with protective overcoat) has the lowest initial OTR and WVTR, and is able to maintain these low transmission rates after retort, MATS, and irradiation. However, Pouch B, undergoes a substantial increase in OTR and WVTR after PATS, as does Pouch C. Barrier performance of the Retort pouch is virtually unaffected by the retort, PATS, and irradiation processing methods. Cross sectional layer analysis shows no occurrence of delamination between the layers of the film structure after processing, and are representative of all pouches pre- and post- processing. A clear trend of higher overall quality for Creamy Cajun Chicken processed utilizing MATS, PATS, and Irradiation, as opposed to the conventional retort method, was observed. Similar trends were reported for appearance, odor, flavor, and texture. Sensory analysis did not reveal any difference in attributes, with respect to the pouch type. Vitamin loss after 9 months (based on initial calculated concentration) for Pouch B samples, processed using the various methods, is as follows: Folic Acid 9-44%, Vitamin C 30-45%, Vitamin A 30-34%, and Thiamin 91-97%. Vitamin analysis shows no clear trend in vitamin loss with respect to processing method.

A down-selection of 3 pouch/processing combinations was conducted based on the results obtained to date, which includes mechanical integrity, barrier performance, seal strength, layer analysis, and sensory data. The pouch/process combinations include Pouch B/MATS, Pouch B/Irradiation, Pouch B/Retort, and a control foil pouch/retort. The action to exercise options under the current contract with Ameriqual have been made, and should be finalized in the coming months. Processing trials at Ameriqual and their sub-contractors are tentatively planned for November 2015.

Processing/packaging effort: in the last nine months we have (1) conducted all year-2-scheduled processing trials (microwave-assisted, pressure-assisted, irradiation, and standard retort sterilization) with all possible innovative packaging materials (coated clear polymer pouches and standard foil/laminate MRE pouches); (2) analyzed the physical, mechanical, and barrier properties of the pouches before and after processing; and (3) evaluated the quality of a model food system (creamy cajun chicken). Processing affected the tensile strength, burst strength, microscopic appearance (bubbling) and elastic modulus of the individual pouch materials, and produced color changes in the samples. Product color degradation (i.e., browning) resulted from process type according to: retorting > MATS > PATS > irradiation.

For the 3-months remainder of the year, we will begin analyzing the 1 year pulls for bars and beverage bases stored for 1 year at 70F and 100F, and conduct additional barrier/layer analysis of the packaging material and conduct sensory analysis of stored product.

1) Multiple contracts for this project were established or are pending award. These included: a contract to Vision Technologies, Inc. for procurement of vitamins and encapsulation of each vitamin separately in a lipid-based coating or a carbohydrate-base coating; a contract to Covance Co. for multiyear analysis of vitamin contents in stored prototypes; contracts for development and provision of advanced non-foil, high-barrier packaging materials consistent with new sterilization technologies (i.e., to Rollprint Packaging Products, Inc. for pouches that employ an aluminum oxide coating, to Toppan Printing Company for pouches that employ an aluminum oxide coating with an added protective over-coating, and to Kuraray America for pouches that employ a nanocomposite coating); and a contract (vendor identified, with expected award in August 2013) for advanced processing of the selected high aw food prototype by non-conventional methods (i.e., by microwave sterilization, high-pressure sterilization, and irradiation sterilization). Each contract required development of and submission of multiple mandated procurement documents to the Natick Soldier Research Development and Engineering Center Acquisition Directorate, including: thorough market research of each industry; independent government cost estimates; statements of work; selection criteria lists; and contract data requirements lists. Each contract furthermore required mandatory bid solicitation followed by written determination of the compliance of each vendor response with the stated requirements.

2) Vitamin encapsulation completion: The five vitamins were successfully coated, separately, with a carbohydrate-based (gum Arabic/maltodextrin) and with a lipid-based (hydrogenated cottonseed oil) encapsulant.

3) Development of prototype matrices: Two food matrices—one compressed; one dispersed powder—each with high and low lipid contents, were successfully developed. These are: Blueberry Granola Bars, with 25% and 10% lipid contents; and Chocolate-Hazelnut Drink Mixes, with 35% and 5% lipid contents. The compositions were established after preliminary studies in which maximum and minimum lipid levels were determined based on product functionality and organoleptic quality. The products were fortified with 2X the space flight requirement of each vitamin/encapsulant and subjected to 4 weeks at 120oF storage in order to verify maintenance of organoleptic quality at that vitamin loading. Nine-point-hedonic sensory testing (with a score of 1 indicating extremely poor quality and a score of 9 indicating extremely good quality) after storage yielded overall acceptance scores > 6.2 for each product (well within the acceptable range).

4) Vitamin analysis contract establishment: A schedule for anticipated submission of stored samples was forwarded to Covance Co.

5) Production of high storage temperature test samples: eight prototypes (the four versions described in (3), each with lipid-coated and carbohydrate-coated vitamins) for initial vitamin retention assessment were produced at 2X the space flight requirement for each vitamin and placed in 120oF storage for 4 weeks. Samples were pulled on July 16 and sent to Covance Laboratories for vitamin analysis. Results are expected August 2, and will guide formulation of samples to be produced for the 3(/5) year storage study.

6) Establishment of contracts for, and receipt of, non-foil, high-barrier packaging materials (vendors listed in (1)): Pouches from Toppan and Rollprint have been delivered to NSRDEC and visually inspected, and preliminary testing of seal strength has commenced; pouches from Kuraray are expected to be delivered in August 2013.

7) Submission of all contract documents for advanced processing: This contract, for production and sterilization processing of a high water-activity item (Creamy Cajun Chicken), is currently under solicitation, with the likely vendor identified. Award is expected in August, 2013. The contractor will produce the food, fill pouches, and conduct or oversee commercial sterilization trials that will utilize: conventional retorting, Microwave Assisted Thermal Sterilization (MATS), Pressure Assisted Thermal Sterilization (PATS), and irradiation processing. This contract will be awarded for 1 year of processing trials with an option for a second year of refinement-of-parameters processing trials, the exact nature of which will depend on Year 1 results.