FDS308 Food Tech: Practical Report on Water Holding Capacity of Meat

This practical report investigates the impact of pH and salt concentrations on the water holding capacity of meat. The experiment involved adjusting the pH of minced meat samples using HCl and NaOH solutions, as well as incorporating NaCl and sodium triphosphate. The results indicate that water holding capacity is significantly influenced by pH levels, with the isoelectric point observed at pH 5.5 where water retention is minimized. The addition of salts, such as NaCl, was found to enhance water holding capacity by promoting protein swelling and moisture retention. The study highlights the importance of pH and salt concentration in maintaining meat quality and freshness, crucial factors in meat processing and preservation. The full report, including detailed materials and methods, results, discussion, and references, is available for students on Desklib, along with a wide array of study tools and solved assignments.

Running head; Practical Report 3
Practical Exercise 3
Effect of Ph and salts on water holding capacity of meat
University
Name of the student:

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Table of Contents
Introduction....................................................................................................................................4
Materials and Methods...................................................................................................................5
Results............................................................................................................................................6
Discussion......................................................................................................................................6
Conclusion.....................................................................................................................................8
References......................................................................................................................................9
List of tables
Table 1Shwoing water holding capacity calculation at different ph rates.....................................6

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Introduction
Mammalian muscle flesh contains an estimate of 75% water, 19% protein, 2.5% of
intracellular fat, 1.2% of carbohydrates and 2.3% of soluble nonprotein substances which can
include, nitrogenous compounds and inorganic substances. Muscle proteins are either water-
soluble substances referred to as sarcoplasmic or in salt concentrates referred to as
myofibrillar proteins. There are a wide variety of sarcoplasmic proteins, the majority which
are glycolytic enzymes responsible in glycolytic pathways as observed in energy conversion
pathways. Major abundant myofibrillar proteins include myosin and actin which are essential
in connective tissues functions. Fat meat is often the adipose tissue which is used by the
animals to store energy in form of fats that is glycerol esters combined with fatty acids or in
intramuscular fat which has high quantity amounts of phospholipids and cholesterols, (Li,
Xu & Zhou, 2012).
Water holding retention in fresh meat is an important aspect when freshness aspect is
being desired as it plays a crucial role in both the yield and meat quality. The underlying
principle of water loss or drip is largely influenced by both amounts of space present in the
cells of the muscle and the pH of the tissue. There are other factors which can affect water
holding capacity and dripping factors in meat. They include, a process using techniques
applied, cuts orientation of the meats, temperature level decline after preparation, storage
temperature and freezing rates, (Sharedeh, Gatellier, Astruc & Daudin, 2015).
Water holding capacity in meats often refers to as the ability of post-mortem meat to
retina water throughout the phases even after external forces are applied. In this regard, there
are physical and biochemical factors in meat which have an effect on the water holding
capacity in meats. Net charge effect of meat has an effect on water retention. When meat ph
is at isoelectric point, the net charge of proteins is 0, thus a number of negative and positive
charges are equal. These charges are attached together and this results in the reaction in the
water levels which gain attraction in meats. Further repulsion of like charges can occur in the
myofibril structures which lead to space reduction. The reduced net protein charges often lead
to lowered levels of water holding capacity due to lower available charges in proteins for
water binding and allow compaction of proteins which force water to go to the free
compartment hence its losses, (Lawrie, & Leward, 2016).
Effects of salt on meat have been investigated and studies have shown lower salt

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soluble protein indicating higher extractability especially in breast meat, (Barbut , Zhang &
Marcone, 2005), while elevated sarcoplasmic denaturation of protein incubated at increased
temperatures, (Zhu, Ruusunen, Gusella, Zhou & Puolanne , 2011). With meats especially that
of chicken, water holding capacity characteristics have shown to change tremendously during
the first 24-hour post-mortem. An investigation by Zhuang and Savage, (2012), showed that
water holding capacity was higher at 24 hours post-mortem.
Hence this study sought to identify how to determine procedures utilized for conducting
water holding capacity in meats and further to establish effects of ph and salt contractions
factors on water holding a capacity of meat.
Materials and Methods
in conducting this experiment, ph solutions will be required, 0.1 M HCl, 0.1M NaOH
solution, 3.0% NaCl solution, 0.5% Na triphosphate solution, ph meter, centrifuge and plastic
centrifuged tubes.
A total of 8 centrifuged tubes were labeled and each tube weight measurement was
done. Lean meat was prepared and minced, and then 10 g of the minced meat was transferred
to each centrifuge tube. In each tube, 10 mL of same ph solution was added and mix
thoroughly. Ph measurements were undertaken after this stage. 0.1m of HCL and 0.1M of
NaOH was added in order to adjust the ph to the set target measurements for each tube. When
the ph of the tube was reached, the solution made up to 40mL. Tubes 7 and 8 relevant
electrolyte of either 3% NaCl or 0.5% Na triphosphate was used to make the solution 40Ml.
The following volumes and ph targets were obtained;
Tube 1 - ph 4.0
Tube 2 - ph 4.5
Tube 3 - ph 5.0
Tube 4 - ph 5.5
Tube 5 - ph 6.0
Tube 6 - ph 7.0
Tube 7 - 3.0% NaCl
Tube 8 - 0.5% Sodium triphosphate
After a period of 15 minutes, the tubes were centrifuged for a period of five minutes at
3000rpm then the supernatant was decanted into a beaker. The sediment myofibrils were

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weighed and volumes of supernatant were taken and recorded.

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Results
Experimental
step
Ph 4.0 Ph 4.5 Ph 5.0 Ph 5.5 Ph 6.0 Ph 7.0 3%NaC
l
0.5%Na
triphosphat
e
Tube 1 Tube 2 Tube 3 Tube 4 Tube 5 Tube 6 Tube 7 Tube 8
The weight of
the tube (g)
13.09 13.08 13.21 13.12 13.03 13.11 13.14 13.13
The weight of
the minced
meat
10.61 10.88 10.12 10.08 10.95 10.27 10.20 10.75
Volume of 0.1
M HCl
required to
adjust the Ph
(ml)
2.6 2.3 1.1 0.6 - - - --
Volume of 0.1
M NaOH
required to
adjust ph (ml)
0.6 1.1
Weight of
myofibril
pellet (g)
19.91 13.93 12.09 11.02 13.29 12.99 13.99 15.31
Volume of
supernatant
(ml)
19.91 25.97 28.90 30.59 28.31 28.02 26.21 25.19
WHC 1.87 1.28 1.19 1.09 1.31 1.26 1.37 1.42
WHC % 187% 128% 119% 109% 131% 126% 137% 142%
Table 1Shwoing water holding capacity calculation at different ph rates
Discussion
The above results show that the minced meat is affected by water holding capacity and
its tenderness due to the changing ph. When the ph levels were brought to lower levels of 4.0,
water holding capacity of the meat increased, while when the meat was brought to its
isoelectric point at the angle of myofibrilla proteins after acidic or basic treatment at around
5.5 pHs, there is gain in weight from the previous acidic to basic forms, (Santoz et al., 2016).
This process of the reversibility suggest that tenderness of meat may be a factor of
proteolysis, rather it could lead to further destruction of myofibrillar structures which were
disrupted t the acidic and basic ph after electric repulsion, (Ke, 2006).

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Hence muscle ph plays a key role in water holding capacity of meat. The decrease in ph
due to the progressive post-mortem of meat leads to reduced charges of meat, reduces the net
protein charge, hence diminishing the water holding capacity. An increased decline in ph
leads to the accelerated water holding capacity and reduced weight of sediment meat, (Zhou
et al., 2014).
In the conversion of muscle to meat, there is build up of lactic acid in the tissues which
lead o rescued meat ph. When the isoelectric ph has been attained in the meat, major proteins,
the net charge of the protein is (Zhang et al., 2018 Zhang et, which signifies that there is an
equal number of negative and positive charges. These unlike charges attract each other and
lead to water levels reduction which are responsible for holding the proteins observed in the
table. As there is an occurrence of repulsion of like charges, net charges of myofibril reach
zero which is concurrent to reduction of myofibril structure enabling packing of structures
together, this yield space reduction in the myofibril.
The isoelectric point in this experiment is determined at the point when the water
holding capacity is minimized. This point reflects the equal charges on the negative and
positive sides. From the results, the minced meat has an isoelectric point of ph 5.5. this is the
point where the there is diminished water holding capacity of the meat.
NaCl and alkaline phosphates have an effect on the water holding capacity. There was
an increased level of water holding capacity. Diffusion of sodium and phosphate ions in the
minced meat offers additional moisture which prevents drying of the meat, (Lorenzo,
Dominguez, Fonseca, & Gomez 2014). Sodium Chloride solution promotes swelling of
protein structures which leads to increase int eh repulsive electrostatic force thus allowing the
expansion of filament matrix. The phosphates offer neutralization and cross-linking between
the myosin and action, enabling the dissociation of myosin. Salts has always been used to
increase the water holding capacity of meat, it improves the water binding capacity of the
meat, (Puolanne , Ruusunen & Vainionpää, 2001).
Water holding capacity in meats is preferred and desired so as o allow the meat to
remain in its freshness for a long duration of time. It is a crucial property as it offers desirable
qualities and properties of meat. It is an advantages aspect of meat processing as meat tends
to be of high humidity due to water compaction in the myosin segments.
Cured meat reactions revolve around the addition of nitrite or nitrate with other
ingredients in the meat such as sugar, spices and even salt. Most commonly nitrite is added to
meat, the nitrite compound causes a formation of meat myoglobin formation, which causes

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the formation of brown color in meat. Eventually, the brown cured meat forms nitro
sylhemocrome which forms a pink colored pigment. The pink colour, however, fades off
when the meat is exposed to light and air.
Conclusion
From this experimental study, it is evident that water holding capacity in meats is very
crucial. Ph and salt concentration in meat products play key roles in enhancing and reducing
water holding capacity in meats. When meat is at isoelectric ph, water holding capacity tends
to decrease water content in meats. Addition of salts to meat tends to an improved water
holding capacity in the myofibril of meat hence improving the overall meat quality.

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References
Barbut, S., Zhang, L., & Marcone, M. (2005). Effects of pale, normal, and dark chicken
breast meat on microstructure, extractable proteins, and cooking of marinated fillets.
Poultry Science, 84(5), 797-802.
Domínguez, R., Gómez, M., Fonseca, S., & Lorenzo, J. M. (2014). Effect of different
cooking methods on lipid oxidation and formation of volatile compounds in foal
meat. Meat science, 97(2), 223-230.
Ke, Shuming, "Effect of pH and salts on tenderness and water -holding capacity of muscle
foods" (2006). Doctoral Dissertations Available from Proquest. AAI3215890.
https://scholarworks.umass.edu/dissertations/AAI3215890
Lawrie, R. A., & Ledward, D. A. (2006). The structure and growth of muscle: Lawrie’s meat
science.
Li, S., Xu, X., & Zhou, G. (2012). The roles of the actin-myosin interaction and proteolysis in
tenderization during the aging of chicken muscle. Poultry science, 91(1), 150-160.
Lorenzo, J. M., Fonseca, S., Gómez, M., & Domínguez, R. (2015). Influence of the salting
time on physico-chemical parameters, lipolysis, and proteolysis of dry-cured foal
"cecina". LWT-Food Science and Technology, 60(1), 332-338.
Puolanne, E. J., Ruusunen, M. H., & Vainionpää, J. I. (2001). Combined effects of NaCl and
raw meat pH on water-holding in cooked sausage with and without added phosphate.
Meat Science, 58(1), 1-7.
Santos, C., Moniz, C., Roseiro, C., Tavares, M., Medeiros, V., Afonso, I., ... & da Ponte, D. J.
(2016). Effects of Early Post-Mortem Rate of pH fall and aging on Tenderness and
Water Holding Capacity of Meat from Cull Dairy Holstein-Friesian Cows. Journal
of Food Research, 5(2), 1.

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Sharedeh, D., Gatellier, P., Astruc, T., & Daudin, J. D. (2015). Effects of pH and NaCl levels
in a beef marinade on physicochemical states of lipids and proteins and on tissue
microstructure. Meat science, 110, 24-31.
Zhang, X., Wang, W., Wang, Y., Wang, Y., Wang, X., Gao, G., ... & Liu, A. (2018). Effects
of nanofiber cellulose on functional properties of heat-induced chicken salt-soluble
meat protein gel enhanced with microbial transglutaminase. Food Hydrocolloids.
Zhou, F., Zhao, M., Zhao, H., Sun, W., & Cui, C. (2014). Effects of oxidative modification
on gel properties of isolated porcine myofibrillar protein by peroxyl radicals. Meat
science, 96(4), 1432-1439.
Zhu, X., Ruusunen, M., Gusella, M., Zhou, G., & Puolanne, E. (2011). High post-mortem
temperature combined with rapid glycolysis induces phosphorylase denaturation and
produces pale and exudative characteristics in broiler Pectoralis major muscles.
Meat Science, 89(2), 181-188.
Zhuang, H., & Savage, E. M. (2012). Postmortem aging and freezing and thawing storage
enhance ability of early deboned chicken pectoralis major muscle to hold added salt
water. Poultry science, 91(5), 1203-1209.