University Practical Report: FDS308 Beetroot Canning Analysis

This report details a practical experiment on the canning of beetroots, focusing on the effects of different pH levels (acidic and non-acidic packs) on the preservation process. The introduction provides background information on canning, betalains, and the role of pH in food preservation, particularly in relation to Clostridium botulinum. The materials and methods section outlines the preparation of beetroots, the use of acetic acid, and the heat treatment process, including autoclaving. The results section presents the physical characteristics of the packs (color, texture, pH), heat penetration curves, and lethality time curves. Tables display the data on physical characteristics, heat curves, and F-values. The discussion analyzes the impact of pH on betalain stability and the canning process, emphasizing the importance of F-values in sterilization. The report concludes that canning is crucial for food preservation, highlighting the effects of pH on the canning method and the significant role of F-values. References are provided to support the findings and analysis.

Running head; Practical Report 6
Practical Exercise 6
Canning of Beetroot Lab report
University
Name of the student:

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Table of Contents
Introduction....................................................................................................................................3
Materials and methods...................................................................................................................5
Results............................................................................................................................................6
Discussion......................................................................................................................................8
Conclusion...................................................................................................................................10
References....................................................................................................................................11

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List of tables
Table 1 showing the physical characteristics of the two packs.............................................5
Table 2 Heat curve display of the two packs.........................................................................5
Table 3 Lethality versus time curve......................................................................................6
Table 4 Non-acidic pack........................................................................................................7
Table 5 F-values comparative results of the acidic pack and the non-acidic pack can.........7

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Introduction
Canning is a preservation method utilised in food processing arena using sealed tight
containers. Canning provides shelf life up to five years depending on the storage
circumstances. Canning has been extensively been used in fruits and vegetables hence
making them available throughout the year. Most of the canned fruits are high in acid and
have high ph ranges hence applied pasteurization. Over-processing of fruits often result in
softer texture and color, (Straus et al., 2012).
Canning of beetroots has been undertaken for preservation purposes. Beetroots have
betalains, which are water soluble elements, nitrogen compounds having red betacyanins
and the yellow betaxanthins. The major pigment present is benzathine which has 95% of the
total betacyanin. The yellow pigment is referred to as vulgaxanthin which is derived from
betanin, (Ravichandran et al., 2013).
Betanin has an active ph range of 3.5-7.0. It is stable at between ph 4.0 and 5.0. heat
effects often lead t partial degradation of benzathine which lead to reduced intensity of
beetroot color. Benzathine oxidation further leads to pigment loss. When there is excess
oxygen supply, betanin oxidation tends to increase following pseudo-first –order.
Ph is a critical factor in the canning of foods. It determines the processing type of
foods. Acidic foods fruits such as prickles having high or lower ph than 4.6 can be canned in
the water bath while low acid foods such as vegetables and meats having ph above 4.6 can
be canned in the pressure canner, (Huang & Von, 1987).
Ph prevents botulism in canning. Clostridium botulinum bacteria has been the main
factor for low acid foods hence canned using a pressure canner. The pores of Clostridium
botulinum spores have survival ability at 212 degrees F and portray growth in a sealed jar
having a low acid level. The spores can undergo vegetative stage which produces deadly
botulism traits. Food fruits such as tomatoes can be canned with the addition of an acid due
to their ph being above 4.6, hence citric acid or lemon juice is added prior to the canning
process.
Heat subjection on beetroot has effects on the cell membrane through the
phospholipids layers. When beetroot is heated the molecules underlying it tend to increase
which disrupts the cell membrane thus affecting the pigment membrane. Beetroots have a
half-life of 413 mins at 25 degrees centigrade, however, when subjected to ascorbic acid,

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they tend to speed up, (Washburn & Jensen, 2017).
Canning utilizes the principles of pasteurization which entails the destruction of
bacteria and its spores present in the food product. Heat treatment is meant to either
inactivate the bacteria or kills them. If the spores are completely killed, the products enter
the vegetative stage which spoils the canned fruits. Thus sterilization is applied to give an
intense heat for a short period of time, (Hillers & Powers –Hammond, 2018).
Heat treatment subjected during the treatment is measured using the F-Value concept.
Heat applied to food component referred to two basic concepts of heat treatment
temperature. F value refers to the heat treatment amount which certain product is subjected
to which represents heat treatment time and temperature of heat treatment, (Vaclavick &
Christin, 2014).
Assessment of product temperature during the thermal phase entails assessing the
critical thermal point and summarizing the F-value. Temperature noted during the critical
thermal point corresponds to the partial F value. Hence all values obtained at the starting
point through the cooling phase till the product temperature and cooling phase are vital as it
accumulates the summery of F value, (Nayak, Liu & Tang, 2015).
This study sought to establish the role of ph on heat processing of beetroots canning
process and to assess factors and impacts of canning beetroots at different acidic and basic
conditions. As heat is an important aspect in sterilization, this study seeks to find out the
effects of heat on quality of canned products and understanding how the critical F value
ranges from the beetroot caning.
Materials and methods
In conducting this experiment, the following materials were utilized; beetroots, NaCl,
sucrose, acetic acid, and temperature controlled autoclave, ph meter, spectrophotometer, and
250 ml glass jars. Methodological approach in this experiment engaged preparation of the
beetroot fruit, blanching process for 20 minutes and slicing the beetroots and preparation of
two sets of steamed beetroots. The first set of the beetroot was subjected to an acid pack. 20
ml of 10% food grade glacial acetic acid vinegar having 10% acetic acid was used filled
with the brine solution to 10 ml and closed with a lid.
In the nonacidic pack, the jar was filled with brine and closed. The asset jar was
placed in a boiling water bath for 30 minutes and then cooled for 40 minutes and the
temperature recorded every minute. The jar was placed in an autoclave process at 115
degrees Celsius for 30 minutes and temperature recorded during the heating and cooling

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process. The two packs were opened and different parameters were assessed in terms of
color, slice, texture, and ph of the brine.
Results
Physical characteristics of the two packs were recorded as follows after the
experiment;
Acidic jar Non-acidic jar
Brine color and clarity Thick dark Dark watery
Slice color Purple Purple
Slice texture Firm ribbed feel Firmed ribbed feel
Brine ph 3.71 5.36
Table 1 showing the physical characteristics of the two packs
Heat penetration curves display for the two jars
Time (Min)
3
6
9
12
15
18
21
24
27
30
0
50
100
150
200
250
Temperature (degrees celsius)
Non Acidic pack
Temperature (degrees celsius)
Acid Pack
Table 2 Heat curve display of the two packs

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Lethality time curves
Acid pack can
1 3 5 7 91113151719212325272931
0
100000000
200000000
300000000
400000000
500000000
600000000
700000000
800000000
900000000
L-value
Time in min
Table 3 Lethality versus time curve
Non-acid pack can
L-Values x10-11

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0 10 20 30 40 50 60 70 80 90 100 110
0
20
40
60
80
100
120
0.00
0.00
0.00
Time (min)
Temperature (°C)
L-values
Table 4 Non-acidic pack
Comparison of F values in the two processes
Time
3
6
9
12
15
18
21
24
27
30
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Non acid pack
Acid pack
Table 5 F-values comparative results of the acidic pack and the non-acidic pack can
Evaluation of heat processing
There was an increased level of heat produced in the acid pack can. This is exhibited
A
B

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with the diagrammatic representation showing the heat exchange output and the F value plot
analysis.
Area of A = Approximately = 217 small squares
Area of B = Approximately = 156 small squares
F 0 of the process of beetroot area of A = 217/156
= 3.8 minutes (at 220 oC)
Discussion
Betalain pigment in beetroots occurs in two forms betacyanin and betaxanthin.
Betacyanin present in roots is referred to as betanin. The stability of betacyanin is highly
depended on the ph ranges of 3-7, with optimum value being achieved at 4-5. The spectrum
ranges occur from pink to red. Beetroot acidity determines safe use of canning method to be
utilized, (Hatlestad et al., 2015).
The spectrum color changes are unstable in presence of light and oxygen and are often
degraded by the high-temperature environment. Extreme temperature interferes with the
bonding of hydrogen. High ph denatures the membrane of the cell wall and hence the
pigment colorization being observed. The color pigments don't cross the membranes due to
large size and varying polarity, (Mikolajczyk-Btaor & Czapsaki, 2017). After the alteration
of proteins shapes, the passage is achieved through diffusion. Alkaline ph changes the
solution which makes to have yellow wavelengths. Betacyanin is not ph indicators in
beetroots, but the color persistence is wide over wide ph range. Their stability is achieved
between 3-7, (Cejudo-Bastante, Hurtado, Delgaldo & Heredia, 2016).
Canning of the beetroots using acid pack has a ph range of 4.6 or lower. Acidic foods
are safely processed using the boiling method in water canner, without any addition of
lemon, vinegar or citric acid. This is crucial for the control of botulinum bacteria. Acidity in
fruits can be natural or made through the addition of acidic substance. Hence beetroot
canning is suitable when performed at the non-acidic range. Acidic media foods contain acid
which is able to block the growth of bacteria and required more heating. Low acids foods
such as meats, seafood, milk, and vegetables often have their recipes as lemon juice, critic
acid or addition of vinegar. Presence of botulinum makes this food hard to be treated with
boiling. The higher the canner temperature the more the bacteria are destroyed, (Mello et al.,
2015).

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Canned beetroots are convenient as it enhances availability throughout the year. Foods
canned using acid pack method having ph range only require pasteurization. An over-
processing process of the fruits often yield to nutrient losses, thus canning of fruits using
acid pack offers good retention of nutrients and flavor.
F value is the overall amount of heat treatment which facilitates full sterilization of the
product. F value is obtained during the sterilization phase, readings per minute need to be
taken during the entire sterilization phase. Amount of heat applied t food products are a
combination of two components which include heat treatment temperature and time of heat
treatment, thus canned product needs to have a combination of heat treatment and heat
treatment temperature, (Paciulli, Medina-Meza, Chiavaro, & Barbosa-Cánovas, 2016).
In the experiment, different F values were obtained due to the different temperature
ranges subjected to the beetroot both the acid packed and non-acid pack. Equal heat
treatment is often achieved when lower temperature exposed to high heat treatment or
subjecting high temperature in the short time. Thus, in this case, both durations of time are
applied in the two processes hence the same amount of heat is not obtained.
Conclusion
Canning of foods is a key component in ensuring food preservation. Canning of
beetroot fruit under the two conditions that is acidic and non-acid pack shows how different
aspect of ph ranges affects the treatment process of canning methods. Addition of ph
solution to foods plays a key role in enhancing stoppage of harmful bacteria from occurring.
F value plays a significant role in establishing the lethal activity of canned food products.

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References
Cejudo-Bastante, M. J., Hurtado, N., Delgado, A., & Heredia, F. J. (2016). Impact of pH
and temperature on the color and betalain content of Colombian yellow pitaya peel
(Selenicereus megalanthus). Journal of food science and technology, 53(5), 2405-
2413.
Hatlestad, G. J., Akhavan, N. A., Sunnadeniya, R. M., Elam, L., Cargile, S., Hembd, A., ...
& Lloyd, A. M. (2015). The beet Y locus encodes an anthocyanin MYB-like protein
that activates the betalain red pigment pathway. Nature Genetics, 47(1), 92.
Hillers, V., & Powers-Hammond, L. (2018). Canning fruits.
Huang, A. S., & Von Elbe, J. H. (1987). Effect of pH on the degradation and regeneration of
betanin. Journal of Food Science, 52(6), 1689-1693. http://dx.doi.org/10.1111/j.1365-
2621.1987.tb05907.x.
Mello, F. R. D., Bernardo, C., Dias, C. O., Gonzaga, L., Amante, E. R., Fett, R., & Candido,
L. M. B. (2015). Antioxidant properties, quantification and stability of betalains from
pitaya (Hylocereus undatus) peel. Ciência Rural, 45(2), 323-328.
Mikołajczyk-Bator, K., & Czapski, J. (2017). Effect of pH changes on antioxidant capacity
and the content of betalain pigments during the heating of a solution of red beet
betalains. Polish Journal of Food and Nutrition Sciences, 67(2), 123-128.
Nayak, B., Liu, R. H., & Tang, J. (2015). Effect of processing on phenolic antioxidants of
fruits, vegetables, and grains—a review. Critical reviews in food science and
nutrition, 55(7), 887-918.
Paciulli, M., Medina-Meza, I. G., Chiavaro, E., & Barbosa-Cánovas, G. V. (2016). Impact
of thermal and high-pressure processing on quality parameters of beetroot (Beta
vulgaris L.). LWT-Food Science and Technology, 68, 98-104.
Ravichandran, K., Saw, N. M. M. T., Mohdaly, A. A. A., Gabr, A. M. M., Kastell, A.,
Riedel, H., Cai, Z., Knorr, D., & Smetanska, I. (2013). Impact of processing of red

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beet on betalain content and antioxidant activity. Food Research International, 50(2),
670-675.
Straus, S., Bavec, F., Turinek, M., Slatnar, A., Rozman, C., & Bavec, M. (2012). Nutritional
value and economic feasibility of red beetroot (Beta vulgaris L. ssp. vulgaris Rote
Kugel) from different production systems. African Journal of Agricultural Research,
7(42), 5653-5660.
Vaclavik, V. A., & Christian, E. W. (2014). Food Preservation. In Essentials of food science
(pp. 323-342). Springer, New York, NY.
Washburn, C., & Jensen, C. (2017). Pretreatments to Prevent Darkening of Fruits Prior to
Canning or Dehydrating.