Service Case Humidification


The Role of Relative Humidity

The role of relative humidity in the perishable products industry is to maintain quality and to extend shelf life. Temperature, relative humidity, air movement, thermal radiation and structural design all interrelate to create conditions that enhance or detract from product quality. The overall weight, quality and freshness of products are immensely affected by changes in these environmental variables.

Temperature is the key to understanding relative humidity. Warm air has the capacity to hold more moisture than cold air. This is especially true with service cases, which often have lower operating temperatures resulting in less humidity, which can negatively affect the product.

SALES INCREASE

Meat, seafood and poultry have a high percentage of moisture as shown in the table below. The loss of moisture is a major factor in contributing to product weight loss; drop in quality and deterioration of product color.

Meat Composition
Cut % Water % Protein % Fat
Beef 60 18 22
Pork 42 12 45
Turkey 58 20 20
Chicken 65 30 5
Fish 70 20 10
Source: USDA 1996

By maintaining the proper relative humidity level, the drying effect of the cold temperature and circulating air is dramatically reduced, as well as improving the meat bloom, making it more appealing to today’s disserting consumers. Thereby increasing sales through extended shelf life.

SHRINK REDUCTION

Research shows a dramatic reduction in shrinkage resulting from the use of humidification in service cases. The following tables compare the shrinkage in a meat case and a deli case in a typical supermarket.

Puremist - SCH System "ON"
Relative Humidity: 94%
Item Beginning Weight 24 Hr. Weight % Change
New York Steak 0.72 0.70 -2.7%
T-Bone Steak 1.17 1.15 -1.7%
Tenderloin - Beef 0.42 0.41 -2.3%
Top Sirloin 1.30 1.26 -3.0%

No System "OFF"
Relative Humidity: 72%
Item Beginning Weight 24 Hr. Weight % Change
New York Steak 0.66 0.61 -6.1%
T-Bone Steak 1.15 1.07 -6.9%
Tenderloin - Beef 0.28 0.26 -8.0%
Top Sirloin 1.38 1.26 -8.7%

*Product displayed far better with Raytec system “ON” according to store personnel. Slight meat sales increases were noted and there were very positive customer comments about fresh appearance.

**Relative humidity reading was taken approximately three feet down stream from the nozzle. Controller was set to turn on every 5 minutes for a 20 second duration.

Puremist - SCH System "ON"
Relative Humidity: 97%
Item Beginning Weight Weight Loss 2 Hr. Weight Loss 4 Hr. Weight Loss 6 Hr. Weight Loss 8 Hr. Net Gain
Swiss 0.51 0.50 0.52 0.52 0.53 +3.9%
Provolone 0.49 0.50 0.50 0.51 0.51 +4.0%
Roast Beef 0.50 0.51 0.50 0.50 0.50 No Loss
Turkey Breast 0.52 0.53 0.53 0.52 0.52 No Loss
Baked Ham 0.49 0.51 0.51 0.52 0.53 +8.2%
Pastrami 0.51 0.51 0.52 0.52 0.52 +1.9%

No System "OFF"
Relative Humidity: 72%
Item Beginning Weight Weight Loss 2 Hr. Weight Loss 4 Hr. Weight Loss 6 Hr. Weight Loss 8 Hr. Net Gain
Swiss 0.49 0.48 0.48 0.47 0.47 -4.1%
Provolone 0.50 0.50 0.50 0.49 0.49 -2.0%
Roast Beef 0.54 0.54 0.53 0.52 0.52 -3.7%
Turkey Breast 0.52 0.52 0.52 0.50 0.50 -3.8%
Baked Ham 0.52 0.52 0.51 0.50 0.50 -3.8%
Pastrami 0.50 0.50 0.50 0.49 0.48 -4.0%

Shrink reduction is the largest single area of benefit. Use of a Raytec Service Case Humidification (SCH) system results in an estimated savings as seen in the following table, based upon individual shrink studies:

Meat Deli
Estimated Average Weekly Sales $10,000 $10,000
Average Weekly Shrink Loss $650 $350
Estimated Weekly Shrink Savings $325 $175
Savings Per Year $16,900 $9,100
Note: Actual shrink results will vary depending on case configuration, maintenance and store personnel use.

These savings are based upon and average weekly loss of 6.5% for meat cases and 3.5% for deli cases and a documented benefit of shrink reduction of approximately 50%.

In today’s 24-hour format maintaining proper moisture levels is especially difficult as store personnel are not constantly present.