Cold Chain Study Final Report

1
Cold Chain StudyFinal Report

• February, 2004

2
Study Objectives

• Objectives for the cold chain study were to
• Document mushroom cold chain performance.
• Farm to shelf time and temperature
• Display case performance
• Display temperatures
• Link cold chain performance to mushroom quality
  and category performance.
• Develop retail recommendations for improved
  mushroom cold chain performance.
• Document the extent that mushroom color/quality
  effects consumer purchase intent.
• Develop a preliminary color chart showing
  optimal mushroom color for peak performance.

3
Approach

• To accomplish the study objectives, PG initiated
  a number of research initiatives. These
  included
• Auditing of cold chain performance from the farm
  through to the retail shelf in three chains, each
  using different distribution methods
• Direct Store Delivery
• Shipment to stores via retailer controlled
  warehouse/trucking
• Shipment to stores via independent
  warehouse/trucking
• Auditing of display case temperatures in sample
  stores.
• Auditing of mushroom temperatures while on
  display in the retail store.
• Modeling of cold chain performance and impacts
  using average, best and worst case scenarios.
• Survey consumers regarding the impact of mushroom
  quality on purchase intent.

4
Executive Summary

• OVERALL FINDINGS
• This study identified that the mushroom cold
  chain often works well. However, there are real
  opportunities for improvement that can
  significantly improve mushroom quality, reduce
  shrink and increase consumer purchase intent and
  satisfaction.
• Across the three supermarket chains studied, cold
  chain from farm to retail shelf showed extreme
  variations in performance that are very likely to
  be negatively impacting mushroom quality and
  consumer purchases.
• Variation in farm to shelf cold chain performance
  is exacerbated by high temperatures within the
  store level refrigerated display cases.
  Temperature recorders placed within retail
  displays documented that most refrigeration units
  are set too high to maintain mushroom quality or
  prevent additional product degradation.
• Cold chain performance from the three
  participating supermarket chains was used to
  create time and temperature scenarios to model
  the impact on mushroom quality. These
  temperature scenarios reveal that even under
  average cold chain performance mushroom quality
  can already fall below the consumer acceptability
  threshold when the product is placed on the
  supermarket display. This product will certainly
  be below this threshold shortly after home
  refrigeration by the end consumer.

5
Executive Summary

• RETAIL COLD CHAIN FINDINGS
• Farm to shelf cold chain performance across the
  three participating retail organizations
  documented that extreme time and temperature
  variations exist, even within the same chain.
  While total trip length from farm to shelf
  averaged 2.7 days for the three chains, the worst
  performing stores averaged nearly 5.5 days.
• The stores utilizing Direct Store Delivery (DSD)
  generally showed the best overall time and
  temperature performance. However, variations
  among best and worst shipments across the 3
  distribution methods indicate chain practices are
  as important as the system utilized in moving
  mushrooms from farm to shelf.
• The DSD chain product experienced the lowest
  amount of time above 41 degrees, the shortest
  overall average time to shelf of 2.5 days and the
  lowest percentage of shelf life used.
• Store inventory/ordering and re-supply frequency
  play significant role in total mushroom time to
  shelf and accumulated temperatures. This study
  documents that these factors have as much impact
  as the process used to move mushrooms from farm
  to shelf.

6
Executive Summary

• CONSUMER FINDINGS
• Cleaner, whiter mushrooms are closely linked
  with consumer purchase intent. Mushroom browning,
  even in modest amounts, will cause a large
  segment of consumers to delay a planned
  supermarket purchase.
• Only 28 of consumers describe themselves as
  generally satisfied with the quality of
  mushrooms on display in the retail supermarket.
• 71 of consumers report that in the past year
  they have delayed a planned mushroom purchase due
  to concerns with the quality of mushrooms on
  display at retail stores.
• More than 70 of consumers say they sort through
  displays to find mushrooms that meet their
  quality expectations, potentially damaging the
  remaining product on the shelf.
• When consumers are asked to identify the
  mushrooms that most closely match the quality
  they typically see in the supermarket, 92 say
  they are likely to purchase mushrooms. However,
  if the quality slides only slightly lower, only
  67 of consumers now say they are likely to make
  a purchase.

7
Executive Summary

• RETAIL PERFORMANCE SUMMARY
• Consumer preference studies conducted
  demonstrated that stores merchandising worst
  quality mushrooms could improve volume and dollar
  sales by as much as 156 for sliced mushrooms and
  35 for whole mushrooms
• The gains can be achieved through careful cold
  chain management enabling best quality
  mushrooms to be merchandised
• Improvement from worst and average to best
  case scenarios could generate up to an additional
  368,484 for the category on a chain-wide basis
  per year
• Worst to best projected gains in per store
  per week dollar sales are 165 (Sliced 114,
  Whole 51)
• Measured on national composite per store per week
  volume and pricing bases for a 100 store chain
• Of per store plant to shelf trips measured Best
  Case 16.6, Average Case 48.3, Worst Case
  35
• Measurement determined by amount of shelf life
  lost prior to product being displayed 0-33
  Best, 33.1-66Average, 66.1-100Worst
• Improvement of current worst to average
  performing stores can generate and additional
  249,794 for the chain per year or 137 per
  store per week
• Improvement of current average to best
  performing stores can generate and additional
  87,844 for the chain per year or 28 per store
  per week

8
Executive Summary

• COLD CHAIN MODELINGBulk White Mushrooms
• Whole mushrooms are more resilient than sliced
  mushrooms to variations in retail cold chain
  performance. As a result, whole mushrooms are
  much more likely to reach the retail shelf at
  quality levels acceptable to consumers.
• Using the best case cold chain scenario, whole
  white bulk mushrooms are likely to have
  acceptable quality through two days of consumer
  home refrigeration before falling below the
  threshold of acceptable quality. Using the
  average cold chain model, bulk mushroom quality
  is borderline acceptable while on display at
  retail. In the low performance model, bulk
  mushrooms are likely to quickly fall below
  minimum acceptable quality levels at the time the
  product is stocked on the retail shelf.
• Distribution channel activities are likely to
  trigger between 17-21 loss of moisture weight
  (shrink) in whole, bulk white mushrooms between
  the time the product leaves the farm and when it
  is purchased by a consumer.
• Modeling of the cold chain was developed by Dr.
  Robert Beelman and Dave Weil, Department of Food
  Science, Penn State Univerisity. It is based on
  the time and temperature data accumulated from
  the Farm to Shelf study, display temperature
  audits and product on display measurements at the
  three participating chains

9
Executive Summary

• COLD CHAIN MODELINGPackaged Whole White
  Mushrooms
• Packaged, whole mushrooms are more resilient to
  variations in retail cold chain performance than
  bulk white or sliced white mushrooms. As a
  result, packaged, white mushrooms are much more
  likely to reach the retail shelf with quality
  levels acceptable to consumers.
• Using the best case cold chain scenario,
  packaged whole white mushrooms are likely to have
  acceptable quality through five days of consumer
  refrigeration. Using the average cold chain
  scenario, packaged whole mushrooms are likely to
  have acceptable quality through two days of home
  refrigeration. In the worst case performance,
  these mushrooms will have borderline acceptable
  quality while on display at retail but quickly
  fall below this level once purchased.
• Worst case distribution channel activities are
  likely to trigger a 3 loss of moisture weight
  (shrink) before the product leaves the retail
  shelf.
• Modeling of the cold chain was developed by Dr.
  Robert Beelman and Dave Weil, Department of Food
  Science, Penn State Univerisity. It is based on
  the time and temperature data accumulated from
  the Farm to Shelf study, display temperature
  audits and product on display measurements at the
  three participating chains

10
Executive Summary

• COLD CHAIN MODELINGSliced White Mushrooms
• Sliced mushrooms are more sensitive to the
  variations in the cold chain performance.
• Only the best case cold chain scenario results
  in sliced white mushrooms with acceptable quality
  through the end of the retail shelf cycle. Using
  the average cold chain scenario, sliced white
  mushrooms are only likely to have acceptable
  quality through the beginning of the retail shelf
  cycle. In the worst case performance, these
  mushrooms will have borderline acceptable quality
  while on display at retail but fall below this
  level once purchased.
• Average weight loss of sliced mushrooms was
  significantly less than whole, packaged
  mushrooms.
• Modeling of the cold chain was developed by Dr.
  Robert Beelman and Dave Weil, Department of Food
  Science, Penn State Univerisity. It is based on
  the time and temperature data accumulated from
  the Farm to Shelf study, display temperature
  audits and product on display measurements at the
  three participating chains

11
Farm to Shelf Temperature Tracking
12
TOPLINE RESULTS
Supplier C Direct Store Delivery  100 of the
142 shipments monitored, experienced mean
temperatures above 32F.   28.9 experienced
mean temperatures above 41F.   On average, the
product spent 19.0 hours above 41F   The
average trip length was approximately 2.5
days. Supplier A Wholesaler Distribution  100
of the 69 shipments monitored, experienced mean
temperatures above 32F.  26.1 experienced
mean temperatures above 41F.  On average, the
product spent 21.8 hours above 41F.  The
average trip length was approximately 2.8
days. Supplier B Retailer DC Distribution  100
of the 90 shipments monitored, experienced mean
temperatures above 32F.  54.4 experienced
mean temperatures above 41F.  On average, the
product spent 32.8 hours above 41F.  The
average trip length was approximately 2.9
days.    
13
Initial Conclusions

• Overall Cold Chain Performance
• Significant opportunity for improvement exists.
• Time and temperature results vary dramatically
  when compared across the three chains as well as
  within the same chain.
• Approximately one-half of the product quality
  life is being used during the plant to shelf
  distribution process.
• One-quarter to one-half of the shipments had
  average (mean) temperatures over 41F.
•  
•  

14
Initial Conclusions

• Comparison of Distribution Methods
• Overall, only a modest time/temperature
  differences were recorded among the three
  distribution methods. Mean temperatures for the
  three groups were very close. However, poor
  performing stores at Chain B were considerably
  worse while top performing stores at Chain C were
  significantly better.
• Overall Time/Temperature results for Chain C
  (Direct Store Delivery) were superior to the
  other two distribution methods both in terms of
  average temperature and top performing stores.
• Chain C (DSD) had the shortest average time to
  shelf, but also showed the greatest time
  variation. The time average for the bottom five
  stores for Chain C was the worst of the three
  groups.
• In terms of maximum recorded temperatures, Chain
  C had the lowest maximums overall as well as the
  best performance when isolating the top and
  bottom performing stores.
• Other factors influence the results, so
  differences observed cannot be completely
  attributed to the distribution method.

15
Plant to ShelfSummary Tables
16
Percentage of Shelf Life Used
17
Product QualityDistribution of Results
18
Product Quality ImpactRetailer A
19
Produce Quality ImpactRetailer B
20
Product Quality ImpactRetailer C
21
Typical TripRetailer A
22
Typical TripRetailer B
23
Typical TripRetailer C
24
Mean Temperature
25
Overall Mean Temperature
26
Mean TempRetailer A
27
Mean TempRetailer B
28
Mean TempRetailer C
29
Time Over 41 Degrees
30
Time Above 41 Degrees
31
Time Above 41--Retailer A
32
Time Above 41--Retailer B
33
Time Above 41--Retailer C
34
Max Temperature
35
Maximum TemperatureAll Retailers
36
Maximum TempRetailer A
37
Maximum TempRetailer B
38
Maximum TempRetailer C
39
Trip Length
40
Trip LengthAll Retailers
41
Trip LengthRetailer A
42
Trip LengthRetailer B
43
Trip LengthRetailer C
44
In-Store Temperature Tracking
45
Summary

•   During June-July 2003, store level audits of
  the refrigerated cases used for mushrooms were
  conducted at the three supermarket divisions
• Retailer A8 stores
• Retailer B8 Stores
• Retailer C6 stores

46
Fixture Air Circulation
The air here must be as close as possible to
32F (temptale 1)
to ensure that the air (and product) here is
under 45F. (temptale 2)
47
Fixture Air Circulation
High supply air temperatures usually are due to
improper setpoint.
High return air temperatures when the supply air
temperatures are good are usually due to air
circulation problems. i.e. air curtain blocked,
improper shelving, overstocking, etc.
48
Monitor Placement
Case Back-Supply
Case Front-Return

• Two TT4s were placed in each mushroom display
  case
• One monitor placed in the middle-back of the
  display case to measure supply air temperature.
• One monitor was placed on the return air vent to
  measure return air temperature.

49
Background Information

• The ideal mushroom storage temperature is 32F
• Mushroom freezing point is approximately 30.4F
• In newer dairy-deli cases expect 10F variation
  between supply and return air
• 32F supply results in 42F return air
• In flat racks modified with shelving inserts
  expect up to 15F variation between supply and
  return
• 32F supply results in up to 47F return air

50
Conclusions

• High supply air temperature is a key problem in
  15 of the 20 stores audited
• 7 of 8 Retailer A
• 7 of 8 Retailer B
• 1 of 6 Retailer C
• Usually the high supply air temperature is due to
  incorrect setpoint. Several factors contribute
  to high setpoints
• Inattention
• Fear of freezing
• Setting at compromise temperature for chilling
  and non-chilling items

51
Conclusions

• Air circulation problems are suspected in at
  least 10 of the 20 stores audited.
• 3 of 8 Retailer A
• 6 of 8 Retailer B
• 2 of 4 Retailer C
• Air circulation problems relate to case set up
  and operation. For example
• Proper shelving is important right length,
  right spacing and solid (not wire)
• Proper stocking vents clear, air curtain
  unobstructed, not overloaded, no warm product,
  etc.

52
Store Level Results
53
Retailer A Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
39F is too high. Return air temperatures are
correspondingly high.
Case Manufacturer Hill/Phoenix Case Model
OHP12 Case Type Flat Rack w/ Shelving Insert
54
Retailer A Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
40F is borderline too high. Return air
temperatures are correspondingly high. Variation
in return air temperature indicates possible air
circulation problem and possible loading warm
product..
Case Type Flat Rack w/ Shelving Insert
55
Retailer A Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
38-40F is too high. Return air temperatures are
correspondingly high.
Case Manufacturer Hill/Phoenix Case Model
OHP8 Case Type Flat Rack w/ Shelving Insert
56
Retailer A Results
Case Back -Supply
Case Manufacturer Hill/Phoenix Case Type Flat
Rack/Produce Case
Analysis The supply air temperature is too
warm. Note The case front- return monitor is
missing.
57
Retailer A Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
42-48F is too warm. Return air temperatures are
correspondingly high. Variation in temperature
in both supply and return suggests severe air
circulation problem or refrigeration control
problem.
Case Manufacturer Hussmann Case Type Flat Rack
w/ Shelving Insert
58
Retailer A Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
35-41F is too warm. Return air temperatures are
correspondingly high. Variation in temperature in
both supply and return suggests severe air
circulation problem or refrigeration control
problem.
Case Manufacturer Hussmann Case Model
P2-8EU Case Type Flat Rack w/ Shelving Insert
59
Retailer A Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 45 to
48F is too high. Return air temperatures are
correspondingly high.
Case Manufacturer Hill/Phoenix Case Model
OHP12 Case Type Flat Rack w/ Shelving Insert
60
Retailer A Results
Case Back -Supply
Analysis The supply air temperature is
borderline high. Reducing the setpoint
temperature by 2F would improve product
temperatures without risk of freezing. Note The
case front return monitor is missing.
Case Manufacturer Hill/Phoenix Case Type Flat
Rack w/ Shelving Insert
61
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 36-40F
is too high. The similarity of the supply and
return temperatures suggests possible short
circuiting of the airflow or improper monitor
placement.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
62
Retailer B Results
Case Back -Supply
Analysis Good supply air temperature. Note
The case front-return monitor is missing.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
63
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 40-45F
is too high. The similarity of the supply and
return temperatures suggests possible short
circuiting of the airflow or improper monitor
placement.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
64
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 42-45F
is too high. The similarity of the supply and
return temperatures suggests possible short
circuiting of the airflow or improper monitor
placement.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
65
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 38-45F
is too high. The similarity of the supply and
return temperatures suggests possible short
circuiting of the airflow or improper monitor
placement. Variation in return air temp suggests
severe air circulation problem.
Case Manufacturer Hussmann
66
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
38-39F is too high. Return air temperatures are
correspondingly high. Possible air circulation
problem also.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
67
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 41-43F
is too high. The similarity of the supply and
return temperatures suggests possible short
circuiting of the airflow or improper monitor
placement.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
68
Retailer B Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature at 40 to
45F is too high. Return air temperatures are
correspondingly high.
Case Manufacturer Hussmann Case Type Flat
Rack/Produce Case
69
Retailer C Results
Case Front-Return
Case Back -Supply
Analysis The baseline supply air temperature at
44-46F is too high. Return air temperatures are
correspondingly high.
Case Manufacturer Hussmann Case Type Flat Rack
w/ Shelving Insert Vent Obstructed No Air
Curtain Obstructed No
70
Retailer C Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature is
borderline high. Reducing the setpoint
temperature by 2F would improve product
temperatures without risk of freezing. Some short
circuiting of airflow possible.
Case Manufacturer Hussmann Case Model
PH8-U Case Type Flat Rack w/ Shelving
Insert Vent Obstructed No Air Curtain
Obstructed Yes
71
Retailer C Results
Case Front-Return
Analysis Return air temperatures are higher
than desired, but not unexpected for this type of
case. Keeping return vent unobstructed will
help. Front fences will help keep vents
open. Note The case back monitor is missing.
Case Manufacturer Tyler Case Type Flat
Rack/Produce Case Vent Obstructed Yes, by
bags Air Curtain Obstructed No
72
Retailer C Results
Case Front-Return
Case Back -Supply
Analysis The supply air temperature is
borderline high. Reducing the setpoint
temperature by 2F would improve product
temperatures without risk of freezing. Return air
temperatures are higher than desired, but not
unexpected for this type of case.
Case Manufacturer Tyler Case Type Flat
Rack/Produce Case Vent Obstructed No Air Curtain
Obstructed No
73
Retailer C Results
Case Front-Return
Case Back -Supply
Case Front-Return
Case Back -Supply
Analysis The supply air temperature is
borderline high. Return air temperatures are
correspondingly high.
Case Manufacturer Hussmann Case Type Flat Rack
w/ Shelving Insert Vent Obstructed No Air
Curtain Obstructed No
74
Retailer C Results
Case Back -Supply
Case Front-Return
Analysis Return air temperatures are higher
than desired Keeping the air curtain
unobstructed will help.
Case Manufacturer Hussmann Case Type Dairy
Deli Vent Obstructed No Air Curtain Obstructed
Yes, by Product
75
Store AuditsTemperature Averages
76
Temperature Audit Details

• Stores for Retailer A B were audited weekly by
  the Perishables Group. Store audits for Retailer
  C were conducted by the supplier. During the
  audits, hand-held laser temperature recorders
  were used to collect data on individual mushrooms
  and mushroom packages on display.

77
Average MushroomProduct Temperature (On Shelf)
78
Average Mushroom Temperature (On Shelf)