Presentation Department of Food Science and Technology

1. POTATO SNACKS MANUFACTURING
PRESENTED BY
ZAINAB
1
Department of Food Science and Technology

2. POTATO PRODUCTION
 The white or Irish potato is one of the world’s most important food
plants
 Potatoes grow best on lighter soils in comparatively cool and
moist climates.
 Potatoes are grown in nearly every state in the United States,
with concentrations in Maine, New York, Michigan, Wisconsin,
Minnesota, North Dakota, Idaho, Washington, Oregon and
California.
 About 15% of the U.S. crop is produced in the southern states,
particularly Florida.**
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3. HARVESTING, HANDLING ANDSTORAGE OF POTATOES
 Freshly dug potatoes must be properly cured or suberized
(healed from digger and/or other mechanical damage) before
low-temperature storage
 The humidity should be high, that is, 95–99% in a well-ventilated
area to allow suberin formation. Formation of the periderm is
essential to prevent rot or microorganism penetration
 This is determined by tuber variety and expected length of the
storage period. The storage temperature should be low enough to
allow the tuber to go into its rest stage
 Tubers can be stored for up to 10 months if storage conditions
are appropriately controlled throughout the storage pile by airflow
that provides thorough air distribution and proper ventilation
3

4. Potato Chip Manufacturing
Receiving And Grading
 When potatoes are delivered at the chip plant, the receiving clerk
should examine the truck or rail car for the condition of the
vehicle and the overall condition of the load. Acceptability of the
potatoes should be ascertained by:
1) Determining the pulp temperature
2) Examining the condition of the load for freezing injury, off-
odors, cleanliness of the potatoes including freedom from soil,
sprouts, and the soundness, appearance and general
firmness of the tubers
3) Noting if the vehicle is clean and sound
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5. Conti…
4) Sampling the load for quality evaluation by selecting, at random, three
or more 10 to 25 lb sample
5) The samples then should be evaluated for specific gravity and graded
for size and absence of external and internal defects
6) A subsample should be fried, in the plant on the conventional fry line
or in the laboratory, for chip color
7) A reducing sugar evaluation should be made if the potatoes do not fry
satisfactorily
8) If the tubers are destined for storage at the chip plant, a sucrose
evaluation must be made to determine if they are acceptable for
storage
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6. Conti…
 The reducing sugar level should be below0.15%, preferably at
0%, and the sucrose value should be less than 1.50%. If all is
satisfactory, the load can be weighed in as an acceptable load
either for immediate use or for storage
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7. 7

8. DESTONING
 Potatoes are destoned to remove any stones that may be in the
load. Stones cause serious damage to the equipment and
problems in the slicing operation, and typically are removed by
floating the potatoes in water, wherein the stones sink to the
bottom and the tubers float
 This may be done with vertical screws or in riffle-type washers
 In addition to stones, metal, wood, plastic, metal cans, and so on,
must be removed
 Usually, this is accomplished by visual inspection of the tubers on
conveyor belts prior to the next unit operation
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9. PEELING
 Tubers may be peeled in batch machines or in continuous
machines. They generally are peeled using carborundum rolls
or with brushes depending on the age of the tuber. As tubers in
storage age, the peel or periderm increases to several cells
thick and should be removed
 However, freshly dug tubers, and in particular immature tubers,
need only a light brushing to remove peels
 Excessive peel removal means lower chip yield and
increased waste to be disposed
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10. WASHING, SORTING AND TRIMMING
 These unit operations are important for producing clean potatoes
free from defects before slicing. A 1/2-inch deep defective area
represents eight or nine slices that may be defective
 It is much easier and more efficient to remove the defective area
ahead of the slicer and, of course, ahead of the fryer. Some
manufacturers now use electronic sorters ahead of the slicer to
remove off quality potatoes
 By removing defective slices ahead of the fryer, energy
and oil are saved and cooking efficiency is improved
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11. SLICING
 Without doubt, this is the most important operation in a potato chip
plant. Efficient slicing produces clean slices with no feathered
edges or torn pieces
 Good slices adsorb less oil and do not leave potato pieces in the
oil, which hastens its breakdown
 The potato is forced against the inner surface of the slicing head
assembly by centrifugal action
 The slicing head consists of 8 separate slicing head shoes and
knives
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12. Conti…
 A slice is produced as the product passes each knife in a smooth
and uninterrupted manner
 The trailing edge of each slicing casting has a hardened stainless
steel insert
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13. WASHING POTATO SLICES
 There are two schools of thought with regard to washing
following slicing
 Some say there should be no washing of the slices, while
others pay great attention to this operation
 The slices should be free of loose starch before entering the
fryer to prevent oil breakdown and dark specks on the chips
 Washing by agitation and by counter flow of the water so that
clean water is the last water on the slices is recommended
 The temperature of the water may be elevated if sugar is
present in the slices 13

14. 14

15. DRYING OR FRYING
 This unit operation is in evolution because the oil content of the
finished chip is a significant concern to some customers.
 The market share of low-fat to no-fat chips is increasing
 Potato chips be fried in oil for best flavor.
 However, drying by itself or partial drying prior to frying is being
used
 Drying takes much more time and the resultant product is very
mealy with little or no flavor other than dried potato flavor
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16. Conti…
 Turnover of the oil is an important factor to keep in mind when
frying potato chips
 Turnover simply means the amount of oil that is used during a
given run. Ideally, one should hope to turn over the oil each 8-
hr shift
 Assuming a fryer with 1,000 pound oil capacity, and 33% oil
content in the finished chip, the oil would be totally replaced for
every 3,000 pounds of chips produced
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17. Conti…
 Each type of oil imparts different flavors to the chips.
 Some manufacturers always use blends to keep the flavor
more neutral.
 Dried potato chips are dried in conventional or
impingement ovens with no oil.
 The drying process takes much longer, but may enable
easier control of the color and moisture content of the
chips.
 Although the thinner slices dry faster, most dried chips
should be sliced thicker than fried chips.
 Dried chips develop off-flavors more quickly than fried
chips unless they are *blanched before drying.
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18. INSPECTION
 Chips are inspected following the frying/drying operation
to remove discolored, burned, or defective chips. This
was done by “chip pickers” in the past—people on the line
who picked out the bad chips
 Now, electronic equipment is available to “kick out” the
defects—the off-colored or unsuitable chips
 The advantage of electronic inspection is that equipment
works all the time without tiring, and is as effective as
management wants it to be by appropriate adjustments
 It should be noted that any pickout, kickout, or throwout is
costly at this point in a chip plant 18

19. Conti…
 The chip may be worth 25 cents per ounce after frying,
whereas the raw potatoes were worth only 3–4 cents per pound
 One need only compare and see the quick loss of profit by
improper operation of this unit operation
 Defective chips are not desirable, and it behooves individual
plants as well as the industry to present clean, acceptable
chips to customers
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20. SALTING AND SEASONING
 The most important characteristic of any snack food is the taste of
the finished product
 The objective is to give customers the consistent product they
expect every time
 Most snacks, including potato chips, are salted
 Salt is the least costly of all the ingredients and is used to enhance
the flavor of the chips
 Generally, chips are salted directly from the fryer to take advantage
of the hot oil for binding the salt crystals to the chip
 The *Snack Food Association has recommended a salt level of
1.75% plus or minus 0.25%
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21. Conti…
 Potato chips may be seasoned with BBQ, vinegar and onion,
cheese and other flavors
 At the present time, about 25% of the potato chips are flavored with
one or another type of seasoning
 Generally, the seasoning is applied topically in rotary drums or
sprinkled on top like salt is applied
 Many chips are consumed with given dips and salsas. Usually dip
chips, such as the wavy-style chips, are cut thicker
 In very large operations, the flow of chips may be split into two or
more lines, each with a packaging and casing machine, to produce
different-flavored potato chips simultaneously
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22. PACKAGING AND CASING
 Most snacks are packaged on form, fill and seal machines
using specific multilaminated bags for given regions of the
world. Metallized foil is a prominent type of package
 Selection of the packaging material should be based on the
contemplated shelf life of the product
 Long shelf life (over 10 weeks) requires low-moisture/vapor
proof films. All packages should be properly filled, sealed and
coded
 The bag should be full and may be gassed packed using an
inert gas (nitrogen) to prolong the keeping quality of the chips
while in marketing channels 22

23. Conti…
 All packaged snacks should be properly coded with the pull
date (or last date of sale) included
 The code is to protect the manufacturer as well as the customer
and detailed information may prove very helpful
 The last check in the operation is at the case packer to
ascertain that the bag is properly sealed and packaged
 Chips are cased to improve and facilitate handling practices
 Nevertheless, they should be handled with tender, loving care
to prevent breakage and retain product quality 23

24. WAREHOUSING
 Packaged chips are placed in warehouses to await shipment to
distribution centers or stores
 Warehoused chips should be handled with care, and first-in
first-out (FIFO) practice should be followed
 *Warehouses for holding the chips should be operated at or
below room temperatures to prevent shortening their shelf life
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25. QUALITY CONTROL OF POTATO CHIPS
 The quality of potato chips is dependent on the specific gravity
of the raw potato, the quality (*peroxide value and free fatty
acid content) of the oil used in frying, proper salt and
seasoning, and the MVTR (moisture vapor transmission rate) of
the package
 Auditing the finished product for moisture content, oil content,
salt content, color, texture and flavor is a basic requirement.
Evaluation of the seal integrity and gas content of the package
also is required
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26. Conti…
 Good-quality manufactured potato chips have a shelf life of 10
weeks plus or minus 2 weeks depending on storage
temperatures, packaging materials and/or exposure to direct
light
 Store-shelf sampling in the market place is a must to ensure
the quality of the product that reaches the customer
 Customers must be given what they expect under any given
label all the time
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27. DRIED POTATO INGREDIENTS FOR
FABRICATED POTATO SNACKS
 The principal dried potato products that have been used
in fabricated potato snacks are:
(1) Potato flakes
(2) Potato granules
(3) Crushed potato pieces
(4) Potato starch
(5) Potato flour
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28. REFERENCES
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 Hadjivassilis, I., Gajdos, S., Vanco, D., & Nicolaou, M. (1997).
Treatment of wastewater from the potato chips and snacks
manufacturing industry. Water science and technology, 36(2-3), 329-
335.
 Haverkort, A. J., Linnemann, A. R., Struik, P. C., & Wiskerke, J.
S. C. (2023). On Processing Potato 2. Survey of Products,
Processes and Operations in Manufacturing. Potato
Research, 66(2), 339-383.