High-Energy, Nutrient-Dense Emergency Relief Food Product (2002) / Chapter Skim
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3 Processing and Packaging of the Emergency Food Product
3 Processing and Packaging of the Emergency Food Product
Pages 97-128
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From page 97... ...
DESIRABLE CHARACTERISTICS OF AN EMERGENCY RELIEF FOOD PRODUCT The use of a few nutrient-dense products in a variety of emergencies by relief organizations such as the United Nations High Commissioner for Refugees, the World Food Programme of the United Nations, and the International Committee of the Red Cross and Red Crescent, has resulted in anecdotal information about the desirable characteristics of such foods. These characteristics should be taken into consideration during prototype development in order to develop a superior EFP.
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From page 98... ...
. Packaging the EFP to Discourage Diversion Information provided by relief organizations indicate that the high energy content of some EFPs, the density of nutrients in them, and the ease with which they may be carried has resulted in these products being collected by military combatants in emergency situations involving armed conflict.
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From page 99... ...
Meal-size portions should be scored to facilitate partitioning them for children. It is also important that the primary and secondary packages be able to serve additional uses in emergency situations.
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From page 100... ...
Role of Water Activity, Water Mobility, and Water Content in Packaged Food Products Three aspects of water are important to consider in describing a food system: water activity (aw) , water mobility, and water content.
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From page 101... ...
Water activity is a better indicator of food product susceptibility to spoilage than is water content. Dried foods normally contain 2 to 20 percent moisture, corresponding to aw in the range 0.20 to 0.60.
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From page 102... ...
. Maillard Browning Reaction The Maillard reaction leads to brown color and to the appearance of new odors and flavors.
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From page 103... ...
In highly concentrated systems, the Maillard reaction is inhibited or retarded until, at some point, caramelization is more likely to occur than Maillard. Generally, the activation energy of the Maillard reaction increases with decreasing moisture content, suggesting that mobility retardation may be the ratelimiting factor (Labuza and Saltmarch, 1981~.
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From page 104... ...
Therefore, the validity of this effect would need to be tested using EFP prototypes and conditions of storage and use simulating those expected during actual use of the EFP. Nevertheless, the key implication of this issue is that although the sensory quality may decrease and the nutritive value, to a lesser extent, may also be reduced because of the Maillard reaction, proper selection of ingredients for the EFP can help minimize sensory deterioration (e.g., appearance of brown color and firmer texture)
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From page 105... ...
Combination of antioxidants such as /~tocopherol (Han et al., 1991) and ascorbic acid or oc-tocopherol and ascorbyl palmitate (Kaitaranta, 1992)
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From page 106... ...
Ascorbic acid had a similar effect in high-phytate foods (Davidsson et al., 2001a, 2001b, Hurrell et al., 2000~. MICROBIOLOGICAL CONSIDERATIONS The addition of small amounts of solutes and dehydration are two main methods of decreasing aw and of increasing osmotic pressure in a food system to inhibit microbial growth.
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From page 107... ...
Under conditions of limited moisture, mold spore germination and mycelial growth strongly correlate with water mobility (Pham et al., 1999~. For the EFP, the type and composition of ingredients used will influence the interaction of solids with water, thereby affecting water mobility and an, and thus the survival and potential growth of pathogenic microorganisms.
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From page 108... ...
At moisture levels below this point, oxidation may rise again. Thus, there is a line of demarcation for lowering aw: in the aw range of 0.2 to 0.3, lipid oxidation is likely to be accelerated, whereas at aw between 0.3 and 0.6, lipid oxidation and other deteriorative reactions are minimized.
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From page 109... ...
On the other hand, lowering the water content of the product to a dry state (< 5 percent moisture) may promote lipid oxidation.
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From page 110... ...
, a significant decrease in vitamin retention was observed with an increasing aw over the same range. Ascorbic acid degradation studies in a dry model food system indicated that the rate of degradation of this nutrient increased with increasing relative humidity of storage or increasing initial moisture content (Purwadaria et al., 1979~.
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From page 111... ...
Since the development of the technique, the ninepoint hedonic scale has been used extensively and validated by numerous studies of food products. Although there are still issues regarding its use, it
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From page 112... ...
Criteria for determining shelf life must be determined prior to starting the process. However, moisture content, an, lipid oxidation, and vitamin losses can be correlated with sensory changes and serve as indices of stability (Giese, 2000~.
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From page 113... ...
, and includes polyunsaturated fatty acids, which are prone to oxidation. Moisture should be restricted
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From page 114... ...
Acceptably low oxygen levels can be maintained only with packaging materials having sufficient barrier properties. The initial oxygen level and the upper limit of oxygen to be permitted in the package must be set in specifying actual barrier requirements.
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From page 115... ...
calculated that a 1-mil polypropylene coating applied to a foil substrate with an effective surface area for permeation of 0.00004 in2/100 in2 of film would exhibit reduced transmission values of 0.0076 cc/100 in2/day/atm for oxygen and 0.00002 cc/100 in2/day/atm for water vapor. These transmission rates are expected to be sufficient to maintain an oxygen level below 2 percent and to provide acceptable protection against moisture influx for 3 years at 23° C
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From page 116... ...
Because lamination costs are related to quantity, primarily because short-run set-up charges can render lamination costs prohibitive, the trilaminate currently used by the military is recommended (from inside to outside: 0.003- to 0.004-in thick polyolefin/0.00035- to 0.00078in thick aluminum foil/0.0005-in thick polyester tNatick Research, Development, and Engineering Center, 19933~. Other laminations with the recommended properties are also applicable, including the enhanced laminate currently recommended by the military that uses both polyester and nylon for additional protection against distribution (mechanical)
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From page 117... ...
A daily supply of nine bars should be packaged together under a nitrogen f ush or vacuum into a harrier package to provide the barrier against oxygen and moisture needed for extended shelf life. The secondary packaging could be a pouch having a similar construction to that of the trilaminate pouch utilized by the military for long shelf-life rations, which consists, from the inside out, of polyolefin, aluminum foil, and polyester or nylon (defined above)
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From page 118... ...
Flutter Packs The World Food Programme developed a plastic film tube package with unequal amounts of food product sealed into each end. The length of tube between the product catches air during free fall and slows the descent.
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From page 119... ...
Cushioning materials take up substantial warehouse space, are laborintensive to use (primarily for equipment loads that require assembly, but would be less of a concern with uniform loads for items such as the EFP) , and may degrade in high humidity (especially the paperboard honeycomb)
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From page 120... ...
1973. Water activity in intermediate moisture foods.
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From page 121... ...
1978. Relationships of water activity to fungal growth.
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From page 122... ...
1972. The influence of water content and water activity on the sugar-amino browning reaction in model systems under various conditions.
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From page 123... ...
1981. Influence of water activity on stability of vitamins in dehydrated foods.
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1997. Growth of Staphylococcus aureus as related to }70 NMR water mobility and water activity.
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From page 125... ...
1992a. Relationship between water and lipid oxidation rates Water activity and glass transition theory.
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From page 126... ...
1999. Water activity and food preservation.
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From page 127... ...
1987. Adaptation and growth of microorganisms in environments with reduced water activity.
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From page 128... ...
1982. An examination of minimal water activity for Staphylococcus aureus ATCC 6538 P growth in laboratory media adjusted with less conventional solutes.
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