[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.3]
 
[Page 250-251]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
                      Subpart A--General Provisions
 
Sec. 114.3  Definitions.
 
 
    For the purposes of this part, the following definitions apply.
    (a) Acid foods means foods that have a natural pH of 4.6 or below.
    (b) Acidified foods means low-acid foods to which acid(s) or acid
food(s) are added; these foods include, but are not limited to, beans,
cucumbers, cabbage, artichokes, cauliflower, puddings, peppers, tropical
fruits, and fish, singly or in any combination. They have a water
activity (aw) greater than 0.85 and have a finished
equilibrium pH of 4.6 or below. These foods may be called, or may
purport to be, ``pickles'' or ``pickled ______.'' Carbonated beverages,
jams, jellies, preserves, acid foods (including such foods as
standardized and nonstandardized food dressings and condiment sauces)
that contain small amounts of low-acid food(s) and have a resultant
finished equilibrium pH that does not significantly differ from that of
the predominant acid or acid food, and foods that are stored,
distributed, and retailed under refrigeration are excluded from the
coverage of this part.
    (c) Lot means the product produced during a period indicated by a
specific code.
    (d) Low-acid foods means any foods, other than alcoholic beverages,
with a finished equilibrium pH greater than 4.6 and a water activity
(aw) greater than 0.85. Tomatoes and tomato products having a
finished equilibrium pH less than 4.7 are not classed as low-acid foods.
    (e) Scheduled process means the process selected by a processor as
adequate for use under the conditions of manufacture for a food in
achieving and maintaining a food that will not permit the growth of
microorganisms having public health significance. It includes control of
pH and other critical factors equivalent to the process established by a
competent processing authority.
    (f) Shall is used to state mandatory requirements.
    (g) Should is used to state recommended or advisory procedures or to
identify recommended equipment.
 
[[Page 251]]
 
    (h) Water activity (aw) is a measure of the free moisture
in a product and is the quotient of the water vapor pressure of the
substance divided by the vapor pressure of pure water at the same
temperature.
 
[44 FR 16235, Mar. 16, 1979, as amended at 61 FR 14245, Apr. 1, 1996]
 
 
 
[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.5]
 
[Page 251]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
                      Subpart A--General Provisions
 
Sec. 114.5  Current good manufacturing practice.
 
    The criteria in Secs. 114.10, 114.80, 114.83, 114.89, and 114.100,
as well as the criteria in part 110 of this chapter, apply in
determining whether an article of acidified food is adulterated (1)
within the meaning of section 402(a)(3) of the act (21 U.S.C. 342(a)(3))
in that it has been manufactured under such conditions that it is unfit
for food, or (2) within the meaning of section 402(a)(4) of the act (21
U.S.C. 342(a)(4)) in that it has been prepared, packed, or held under
insanitary conditions whereby it may have become contaminated with
filth, or whereby it may have been rendered injurious to health.
 
 
 
[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.10]
 
[Page 251]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
                      Subpart A--General Provisions
 
Sec. 114.10  Personnel.
 
    All operators of processing and packaging systems shall be under the
operating supervisions of a person who has attended a school approved by
the Commissioner for giving instruction in food-handling techniques,
food-protection principles, personal hygiene and plant sanitation
practices, pH controls and critical factors in acidification, and who
has been identified by that school as having satisfactorily completed
the prescribed course of instruction. The Commissioner will consider
students who have satisfactorily completed the required portions of the
courses presented under Sec. 108.35 and part 113 of this chapter before
March 16, 1979, to be in compliance with the requirement of this
section.
 
Subparts B-D [Reserved]
 
 
 
[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.80]
 
[Page 251-252]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
               Subpart E--Production and Process Controls
 
Sec. 114.80  Processes and controls.
 
 
    (a) Processing operations. The manufacturer shall employ appropriate
quality control procedures to ensure that finished foods do not present
a health hazard.
    (1) Acidified foods shall be so manufactured, processed, and
packaged that a finished equilibrium pH value of 4.6 or lower is
achieved within the time designated in the scheduled process and
maintained in all finished foods. Manufacturing shall be in accordance
with the scheduled process. Acidified foods shall be thermally processed
to an extent that is sufficient to destroy the vegetative cells of
microorganisms of public health significance and those of nonhealth
significance capable of reproducing in the food under the conditions in
which the food is stored, distributed, retailed and held by the user.
Permitted preservatives may be used to inhibit reproduction of
microorganisms of nonhealth significance (in lieu of thermal
processing).
    (2) Sufficient control, including frequent testing and recording of
results, shall be exercised so that the finished equilibrium pH values
for acidified foods are not higher than 4.6. Measurement of acidity of
foods in-process may be made by potentiometric methods, titratable
acidity, or colorimetric methods. If the finished equilibrium pH of the
food is above 4.0, the measurement of the finished equilibrium pH shall
be by a potentiometric method, and the in-process measurements by
titration or colorimetry shall be related to the finished equilibrium
pH. If the finished equilibrium pH is 4.0 or below, then the measurement
of acidity of the final product may be made by any suitable method.
Special care should be taken when food ingredients have been subjected
to lye, lime, or similar high pH materials.
    (3) Procedures for acidification to attain acceptable equilibrium pH
levels in the final food include, but are not limited to, the following:
    (i) Blanching of the food ingredients in acidified aqueous
solutions.
    (ii) Immersion of the blanched food in acid solutions. Although
immersion of food in an acid solution is a satisfactory method for
acidification, care must be taken to ensure that the acid concentration
is properly maintained.
    (iii) Direct batch acidification, which can be achieved by adding a
known
 
[[Page 252]]
 
amount of an acid solution to a specified amount of food during
acidification.
    (iv) Direct addition of a predetermined amount of acid to individual
containers during production. Liquid acids are generally more effective
than solid or pelleted acids. Care must be taken to ensure that the
proper amount of acid is added to each container.
    (v) Addition of acid foods to low-acid foods in controlled
proportions to conform to specific formulations.
    (4) Testing and examinations of containers shall occur often enough
to ensure that the container suitably protects the food from leakage or
contamination.
    (b) Coding. Each container or product shall be marked with an
identifying code permanently visible to the naked eye. If the container
does not permit the code to be embossed or inked, the label may be
legibly perforated or otherwise marked, as long as the label is securely
affixed to the product container. The required identification shall
specify in code the establishment where the product was packed, the
product contained therein, and the year, day, and period during which it
was packed. The packing period code shall be changed often enough to
enable ready identification of lots during their sale and distribution.
Codes may be changed periodically on one of the following bases:
intervals of 4 to 5 hours; personnel shift changes; or batches, as long
as the containers constituting the batch do not represent those
processed during more than one personnel shift.
 
 
 
[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.83]
 
[Page 252]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
               Subpart E--Production and Process Controls
 
Sec. 114.83  Establishing scheduled processes.
 
    The scheduled process shall be established by a qualified person who
has expert knowledge acquired through appropriate training and
experience in the acidification and processing of acidified foods.
 
 
 
[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.90]
 
[Page 252-256]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
               Subpart E--Production and Process Controls
 
Sec. 114.90  Methodology.
 
    Methods that may be used to determine pH or acidity for acidified
foods include, but are not limited to, the following:
    (a) Potentiometric method for the determination of pH--(1)
Principles. The term ``pH'' is used to designate the intensity or degree
of acidity. The value of pH, the logarithm of the reciprocal of the
hydrogen ion concentration in solution, is determined by measuring the
difference in potential between two electrodes immersed in a sample
solution. A suitable system consists of a potentiometer, a glass
electrode, and a reference electrode. A precise pH determination can be
made by making an electromotive force (emf) measurement of a standard
buffer solution whose pH is known, and then comparing that measurement
to an emf measurement of a sample of the solution to be tested.
    (2) Instruments. The primary instrument for use in pH determination
is the pH meter or potentiometer. For
 
[[Page 253]]
 
most work, an instrument with a direct-reading pH scale is necessary.
Battery and line-operated instruments are available commercially. If the
line voltage is unstable, line-operated instruments should be fitted
with voltage regulators to eliminate drifting of meter-scale readings.
Batteries should be checked frequently to ensure proper operation of
battery operated instruments. An instrument using an expanded unit scale
or a digital readout system is preferred since it allows more precise
measurements.
    (3) Electrodes. The typical pH meter is equipped with a glass
membrane electrode and a reference electrode or a single probe
combination electrode. Various types of electrodes designed for specific
uses are available. The most commonly used reference electrode is the
calomel electrode, which incorporates a salt bridge filled with
saturated potassium chloride solution.
    (i) Care and use of electrodes. Calomel electrodes should be kept
filled with saturated potassium chloride solution or other solution
specified by the manufacturer because they may become damaged if they
are allowed to dry out. For best results, electrodes should be soaked in
buffer solution, distilled or deionized water, or other liquid specified
by the manufacturer for several hours before using and kept ready by
storing with tips immersed in distilled water or in buffer solution used
for standardization. Electrodes should be rinsed with water before
immersing in the standard buffers and rinsed with water or the solution
to be measured next between sample determinations. A lag in meter
response may indicate aging effects or fouling of the electrodes, and
cleaning and rejuvenation of the electrodes may be necessary and may be
accomplished by placing the electrodes in 0.1 molar sodium hydroxide
solution for 1 minute and then transferring them to 0.1 molar
hydrochloric acid solution for 1 minute. The cycle should be repeated
two times, ending with the electrodes in the acid solution. The
electrodes should then be thoroughly rinsed with water and blotted with
soft tissue before proceeding with the standardization.
    (ii) Temperature. To obtain accurate results, a uniform temperature
should be maintained for the electrodes, the standard buffer solutions,
and the samples. Tests should be made at a temperature between 20 deg.
and 30  deg.C, the optimum being 25  deg.C. Any temperature
determinations made without meter compensation may affect pH values. An
automatic temperature compensator may be used.
    (iii) Accuracy. The accuracy of most pH meters is stated to be
approximately 0.1 pH unit, and reproducibility is usually
0.05 pH unit or less. Some meters permit the expansion of
any pH unit range to cover the entire scale and have an accuracy of
approximately 0.01 pH unit and a reproducibility of
0.005 pH units.
    (4) General procedure for determining pH. When operating an
instrument, the operator should use the manufacturer's instructions and
should observe the following techniques for pH determinations:
    (i) Switch the instrument on and allow the electronic components to
warm up and stabilize before proceeding.
    (ii) Standardize the instrument and electrodes with commercially
prepared standard 4.0 pH buffer or with freshly prepared 0.05 molar
potassium acid phthalate buffer solution prepared as outlined in
``Official Methods of Analysis of the Association of Official Analytical
Chemists'' (AOAC), 13th Ed. (1980), section 50.007(c), under ``Buffer
Solutions for Calibration of pH Equipment--Official Final Action,''
which is incorporated by reference. Copies may be obtained from the
Association of Official Analytical Chemists International, 481 North
Frederick Ave., suite 500, Gaithersburg, MD 20877-2504, or may be
examined at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC. Note the temperature of the
buffer solution and set the temperature compensator control at the
observed temperature (room temperature is near 25  deg.C).
    (iii) Rinse the electrodes with water and blot, but do not wipe,
with soft tissue.
    (iv) Immerse the tips in the buffer solution and take the pH
reading, allowing about 1 minute for the meter to stabilize. Adjust the
standardization
 
[[Page 254]]
 
control so that the meter reading corresponds to the pH of the known
buffer (for example, 4.0) for the temperature observed. Rinse the
electrodes with water and blot with soft tissue. Repeat procedure with
fresh portions of buffer solution until the instrument remains in
balance on two successive trials. To check the operation of the pH
meter, check the pH reading using another standard buffer such as one
having a pH of 7.0, or check it with freshly prepared 0.025 molar
phosphate solution prepared as outlined in the AOAC, 13th Ed. (1980),
section 50.007(e), which is incorporated by reference. The availability
of this incorporation by reference is given in paragraph (a)(4)(ii) of
this section. Expanded scale pH meters may be checked with pH 3.0 or pH
5.0 standard buffers. Buffers and instruments can be further checked by
comparison with values obtained with a second properly standardized
instrument.
    (v) Indicating electrodes may be checked for proper operation by
first using an acid buffer and then a base buffer. First standardize the
electrodes using a pH 4.0 buffer at or near 25  deg.C. Standardization
control should be adjusted so that the meter reads exactly 4.0.
Electrodes should be rinsed with water, then blotted and immersed in a
pH 9.18 borax buffer prepared as outlined in the AOAC, 13th Ed. (1980),
section 50.007(f), which is incorporated by reference. The availability
of this incorporation by reference is given in paragraph (a)(4)(ii) of
this section. The pH reading should be within 0.3 units of
the 9.18 value.
    (vi) The pH meter can be tested for proper operation by shorting the
glass and reference electrode inputs, thereby reducing the voltage to
zero. In some meters this shorting is done by switching the instrument
to standby, and in other instruments by use of a shorting strap. With
the instrument shorted out, standardization control should be turned
from one extreme to another. This operation should produce a deflection
greater than 1.5 pH unit from center scale.
    (5) Determining pH on samples. (i) Adjust the temperature of the
sample to room temperature (25  deg.C), and set the temperature
compensator control to the observed temperature. With some expanded
scale instruments, the sample temperature must be the same as the
temperature of the buffer solution used for the standardization.
    (ii) Rinse and blot the electrodes. Immerse the electrodes in the
sample and take the pH reading, allowing 1 minute for the meter to
stabilize. Rinse and blot the electrodes and repeat on a fresh portion
of sample. Oil and grease from the samples may coat the electrodes;
therefore, it is advisable to clean and standardize the instrument
frequently. When oily samples cause fouling problems, it may become
necessary to rinse the electrodes with ethyl ether.
    (iii) Determine two pH values on the well-mixed sample. These
readings should agree with one another to indicate that the sample is
homogeneous. Report values to the nearest 0.05 pH unit.
    (6) Preparation of samples. Some food products may consist of a
mixture of liquid and solid components that differ in acidity. Other
food products may be semisolid in character. The following are examples
of preparation procedures for pH testing for each of these categories:
    (i) Liquid and solid component mixtures. Drain the contents of the
container for 2 minutes on a U.S. standard No. 8 sieve (preferably
stainless steel) inclined at a 17- to 20-degree angle. Record weight of
the liquid and solid portions and retain each portion separately.
    (a) If the liquid contains sufficient oil to cause electrode
fouling, separate the layers with a separatory funnel and retain the
aqueous layer. The oil layer may be discarded. Adjust the temperature of
the aqueous layer to 25  deg.C and determine its pH.
    (b) Remove the drained solids from the sieve, blend to a uniform
paste, adjust the temperature of the paste to 25  deg.C and determine
its pH.
    (c) Mix aliquots of solid and liquid fractions in the same ratio as
found in the original container and blend to a uniform consistency.
Adjust the temperature of the blend to 25  deg.C and determine the
equilibriated pH. Alternatively, blend the entire contents of
 
[[Page 255]]
 
the container to a uniform paste, adjust the temperature of the paste to
25  deg.C, and determine the equilibriated pH.
    (ii) Marinated oil products. Separate the oil from the solid
product. Blend the solid in a blender to a paste consistency; it may
become necessary to add a small amount of distilled water to some
samples to facilitate the blending. A small amount of added water will
not alter the pH of most food products, but caution must be exercised
concerning poorly buffered foods. No more than 20 milliliters of
distilled water should be added to each 100 grams of product. Determine
the pH by immersing electrodes in the prepared paste after adjusting the
temperature to 25  deg.C.
    (iii) Semisolid products. Food products of a semisolid consistency,
such as puddings, potato salad, etc., may be blended to a paste
consistency, and the pH may be determined on the prepared paste. If more
fluidity is required, 10 to 20 milliliters of distilled water may be
added to 100 grams of product. Adjust the temperature of the prepared
paste to 25  deg.C and determine its pH.
    (iv) Special product mixtures. For special product mixtures such as
antipasto, pour off the oil, blend the remaining product to a paste, and
determine the pH of the blended paste. If more fluidity is required, add
10 to 20 milliliters of distilled water to each 100 grams of product and
blend. Adjust the temperature of the prepared paste to 25  deg.C and
determine its pH.
    (7) Process pH determination. Obtain sample portions of material for
pH determination.
    (i) For process liquids, adjust the temperature of the liquid to 25
deg.C and determine the pH by immersing the electrodes in the liquid.
    (ii) Drain solid materials on a sieve and blend to a workable paste.
Adjust the temperature of the prepared paste to 25  deg.C and determine
its pH.
    (iii) If enough solid materials are available to make a paste, blend
representative aliquots of liquid and solid materials to a workable
paste. Adjust the temperature of the prepared paste to 25  deg.C and
determine the equilibrated pH. Alternatively, blend the entire contents
of the container to a uniform paste, adjust the temperature of the paste
to 25  deg.C, and determine the equilibrated pH.
    (b) Colorimetric methods for the determination of pH. This method
may be used in lieu of the potentiometric method if the pH is 4.0 or
lower.
    (1) Principle. The colorimetric method for pH involves the use of
indicator dyes in solutions that gradually change color over limited pH
ranges. An indicator that has the greatest color change at approximately
the pH of the sample being tested is selected. The pH is determined by
the color of the indicator when exposed to the sample under test.
    (2) Indicator solutions. Most indicator solutions are prepared as a
0.04 percent solution of the indicator dye in alcohol. In testing, a few
drops of indicator solution are added to 10-milliliter portions of the
sample solution. Colors should be compared using a bright background.
Approximate determinations can be made on white porcelain spot plates,
the test colors being compared thereon with a set of color standards.
More accurate colorimetric tests can be made using a comparator block
fitted with sets of tubes of standard indicator solutions of known pH.
    (3) Indicator paper. A paper tape treated with indicator dye is
dipped into the sample solution. Depending upon the pH of the solution,
the tape will change color and an approximate pH can be determined by
comparison with a standard color chart.
    (c) Titratable acidity. Acceptable methods for determining
titratable acidity are described in the AOAC, 13th Ed. (1980), section
22.060, under ``Titratable Acidity--Official Final Action,'' for
``Indicator Method,'' and section 22.061 for ``Glass Electrode Method--
Official Final Action,'' which is incorporated by reference. The
availability of this incorporation by reference is given in paragraph
(a)(4)(ii) of this section. The procedure for preparing and
standardizing the sodium hydroxide solution is described in the AOAC,
13th Ed. (1980), sections 50.032-50.035, under ``Sodium Hydroxide--
Official Final Action'' by the ``Standard
 
[[Page 256]]
 
Potassium Hydroxide Phthalate Method,'' which is also incorporated by
reference and available as set forth in paragraph (a)(4)(ii) of this
section.
 
[44 FR 16235, Mar. 16, 1979, as amended at 47 FR 11822, Mar. 19, 1982;
49 FR 5609, Feb. 14, 1984; 54 FR 24892, June 12, 1989; 63 FR 14035, Mar.
24, 1998]
 
 
 
[Code of Federal Regulations]
[Title 21, Volume 2]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR114.100]
 
[Page 256]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
                          SERVICES (CONTINUED)
 
PART 114--ACIDIFIED FOODS--Table of Contents
 
                     Subpart F--Records and Reports
 
Sec. 114.100  Records.
 
 
    (a) Records shall be maintained of examinations of raw materials,
packaging materials, and finished products, and of suppliers' guarantees
or certifications that verify compliance with Food and Drug
Administration regulations and guidance documents or action levels.
    (b) Processing and production records showing adherence to scheduled
processes, including records of pH measurements and other critical
factors intended to ensure a safe product, shall be maintained and shall
contain sufficient additional information such as product code, date,
container size, and product, to permit a public health hazard evaluation
of the processes applied to each lot, batch, or other portion of
production.
    (c) All departures from scheduled processes having a possible
bearing on public health or the safety of the food shall be noted and
the affected portion of the product identified; these departures shall
be recorded and made the subject of a separate file (or log identifying
the appropriate data) delineating them, the action taken to rectify
them, and the disposition of the portion of the product involved.
    (d) Records shall be maintained identifying initial distribution of
the finished product to facilitate, when necessary, the segregation of
specific food lots that may have become contaminated or otherwise unfit
for their intended use.
    (e) Copies of all records provided for in paragraphs (b), (c), and
(d) of this section shall be retained at the processing plant or other
reasonably accessible location for a period of 3 years from the date of
manufacture.
 
[44 FR 16235, Mar. 16, 1979, as amended at 65 FR 56479, Sept. 19, 2000]