The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and its impact on the symbiotic soft cheese quality

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Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 1/11
The assessment of the antioxidant
and antibacterial activity of Mandarin peel
powder and its impact on the symbiotic soft
cheese quality
Warda Mustafa Abdeltawab Ebid1* , Alla Samy Mohamed2, Mohamed Hussein Roby3
1Fayoum University, Faculty of Agriculture, Dairy Department, Fayoum - Egypt
2Zagazig University, Faculty of Agriculture, Food Science Department, Zagazig - Egypt
3Fayoum University, Faculty of Agriculture, Food Science and Technology Department, Fayoum - Egypt
*Corresponding Author: Warda Mustafa Abdeltawab Ebid, Fayoum University, Faculty of Agriculture, Dairy
Department, 63514, Elfayoum, Egypt e-mail: wma01@fayoum.edu.eg
Cite as: Ebid, W. M. A., Mohammed, A. S., & Roby, M. H. (2024). The assessment of the antioxidant
and antibacterial activity of Mandarin peel powder and its impact on the symbiotic soft cheese quality. Brazilian
Journal of Food Technology, 27, e2023088. https://doi.org/10.1590/1981-6723.08823
Abstract
Mandarin peel powder (MPP), which has a higher polyphenol concentration than edible parts, is the major source
of bioactive ingredients. The total phenolic content (TPC), antioxidant content, and antibacterial activity of several
mandarin peel extracts were evaluated. A starter containing Lactobacillus acidophilus LA5 and Streptococcus
thermophilus as a mixed strain (1:1) with the addition of 1, 3 and 5% of MPP and a control without MPP, was used
to make UF soft cheese. The viability, antioxidant value, total solid (TS) content, pH values, acidity, protein and fat
contents, and organoleptic properties during storage at 5±2 °C for 21 days of soft cheeses were evaluated. The
results revealed that the TPC in methanol extract was the highest and the lowest recorded in acetone extraction, the
same trend found in antioxidant and antibacterial activity. The inclusion of both probiotic strains and MPP improved
antioxidant activity and cheese quality; symbiotic cheese had considerably higher relative degrees of titratable
acidity (TA) and TS than control cheese. The sensory examination revealed that adding the MPP at a ratio of 1%
increased the score. Finally, it is proposed that probiotic soft cheese supplemented by MPP as functional food has
acceptable composition and good sensory features.
Keywords: Mandarin peel; Antioxidant; Antibacterial; Probiotic and symbiotic soft cheese.
Highlights
• Mandarin peel powder (MPP) has a high polyphenol concentration
• MPP can be used as a natural preservative in soft cheese production
• MPP shows significant antioxidant and antibacterial activity
• Incorporation of MPP in soft cheese improves its sensory and functional properties

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 2/11
1. Introduction
Mandarin (Citrus reticulata Blanco) is one of the medicinally essential plants belonging to the Rutaceae
family (Rane Zab Anish Kumar & Bhaskar, 2012); for instance, at least 40% of the 1 million t of mandarin
produced yearly in South Africa are channeled to juice manufacturing with waste computation for 50-70%
of the fresh weight include of pulp (30% to 35%), peels (60% to 65%) and seeds (<10%) (Sharma et al.,
2017). Costanzo et al. (2020) found that the mandarin peel is more abundant in antioxidants than pulp and
may be potentially used as a dietary supplement; a sustainable re-utilization of peels for industrial and
pharmacological applications could represent a vital boost toward a circular economy.
Mandarin peel powders (MPP) can be used as a substitute for synthetic antioxidants to extend the shelf
life of food products containing fats and oils, according to several research (Costanzo et al., 2022; Diaz-
Uribe et al., 2022; Kaur et al., 2021; Lin et al., 2021; Balaky et al., 2020). Citrus peel has a higher polyphenol
content than edible components, thereby making it the most important source of bioactive phenolic
compounds, particularly flavonoids. Flavones, isoflavones, flavonones, and anthocyanins are among the
flavonoid compounds found in citrus (Diaz-Uribe et al., 2022). When comparing the peel and pulp extract of
mandarin to grape peel and seed extract, mandarin peel and pulp extract recorded the highest antibacterial
activity on food spoilage bacteria (Pfukwa et al., 2019).
Soft white cheese accounts for around three-quarters of all cheese made and consumed in Egypt. It is
created by a variety of methods, including normal and ultra-filtration (UF). The use of UF technology in
cheese making has various advantages, including greater output and nutritional value, decreased production
costs, and the elimination of whey disposal difficulties (Coker et al., 2005; Mehaia, 2002).
The purpose of this study was to evaluate the antioxidant and antibacterial activities of five mandarin peel
powder extracts as well as the physicochemical, antioxidant activity, microbiological, and sensory properties
of fortified cheese.
2. Materials and methods
Mandarins (Mediterranean or Willow Leaf Mandarin) were collected from a fruit and vegetable store in
El-Fayoum, Egypt. Rennet powder was obtained from Chr. Hansen (Horsholm Company, Denmark).
According to Ojha et al. (2016), the whole peel was washed well before and after peeling with tap water,
dried at 50°C at a cabinet drier, powdered using an electric 52 grinder, saving at 40 mesh size, packed and
storage at 4oC for use in cheese manufacture.
2.1 Extraction preparation
The mandarin peel extracts were prepared by macerating 200 g of peel for 72 h in 800 mL of solvents
(water, ethanol, acetone, chloroform, and methanol). The extracts were filtered with Whatman filter paper
No. 1 after 72 hours, the solvents were evaporated to dryness, and the samples were kept at 4 oC for use in
antibacterial activity tests.
2.2 Total phenolic content
According to Shaiban et al. (2006), the Folin-Ciocalteau method measured the total phenolic contents
(TPC) of MPP and their extracts. By using gallic acid as a standard, the results were expressed as gallic acid
equivalents (GAE) per g of samples.
2.3 Determination of antioxidant activity
The antioxidant capacity of mandarin peel powder, extracts, and fortified cheese was assessed using the
DPPH radical scavenging ability method at concentrations of (0, 2, 4, 6, 8, and 10 g) for powder and dry
extracts and 0.1, 0.2, and 0.5 g for fortified cheese treatments. By comparing the tested concentrations to a

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 3/11
control, the percent inhibition was calculated. Each concentration was measured three times and the average
value was computed. The inhibitory concentration (IC50) and antiradical power (ARP) were determined.
2.4 The antibacterial activity of Mandarin peel extracts
All the bacteria (Escherichia coli ATCC 25922, Bacillus cereus ATCC 13753, and Staphylococcus aureus
ATCC 8095) were obtained from the culture collection of Agricultural Microbiology Department, Faculty of
Agriculture at Fayoum University. The bacteria were incubated and activated at 30 °C for 24 hours
inoculating in Nutrient Broth (OXOID). Inoculums containing 106 bacterial cells were spread on Mueller-
Hinton Agar (OXOID) plates (1 cm3 inoculum per plate). The discs injected with mandarin peel extracts were
placed on the inoculated agar by slightly pressing and incubated at 35 oC (24 h). The antimicrobial activity
was assessed by measuring the clear zones (mm) around each disc. In each case, triplicate tests were
performed and the average was taken as the final reading.
Mandarin peel extract (MPE) was tested for minimum inhibitory concentration (MIC). The MIC was
measured (Mueller Hinton broth) and incubated at 37 oC for 24 h. For this, serial two-fold concentrations of
each extract (8-1024 µg mL -1) were pipetted into tubes containing 4 mL of Mueller Hinton broth media for
pathogenic bacteria, For pathogenic bacteria, each tube was inoculated with 0.4 mL (0.5 McFarland medium)
of a standardized suspension of bacterial species containing 1x106 cell/mL as the lowest concentration with
an optical density (OD) below or equal to that of negative control. The minimum bactericidal concentration
(MBC) was determined by subculturing the MIC dilutions as well as higher concentrations onto sterile
Mueller Hinton agar plates incubated at 37 ºC for 24 h. The lowest concentration of MPE which completely
killed the tested bacteria was documented as MBC level. All steps were implemented in duplicate and the
mean values were recorded (Neethu et al., 2018).
2.5 Starter activation
The bacterial strains Lactobacillus acidophilus La5 (obtained from Chr. Hansen's laboratories,
Copenhagen, Denmark) and Str. thermophilus (obtained from the Dairy Microbiology Laboratory at National
Research Centre (NRC), Dokki, Cairo, Egypt) were individually activated by three repeated transfers in
sterile 10% reconstituted skim milk powder.
2.6 Cheese making
The dairy processing pilot facility provided milk retentate (Faculty of Agriculture, Fayoum University).
The average milk composition was 35.68% of total solids (TS), 13.05% of protein, and 14.80% of fat, divided
into four equal portions. The MPP (protein 4.19%, lipids 3.82%, moisture 9.5%, fibre 7.93%, carbohydrate
71.25% and ash 3.31%) was added at rates of 1, 3, and 5% (the best percentage based on pre-experimental
trails) to generate three treatments. The latter section contained no MPP and acted as a control. All milk
batches were heated to 75 oC, cooled to 38 oC, and inoculated with the starter culture, L. acidophilus and Str.
thermophilus (1:1) at a rate of 1%, and held for 30 minutes until reached pH 6.4, in addition, calcium chloride
(0.02%) was added to milk retentate with adequate rennet. The pre-cheese was immediately placed in plastic
containers and incubated at the same temperature (38 °C) for 40 minutes to complete coagulation or kept at
38 oC until a uniform coagulum was formed and stored at 5 oC. According to the method described by all
cheese treatments, they were maintained in a refrigerator at 5 oC UF-soft cheese (Grandison, 1993; Shekin,
2021). During the first 21 days of storage, the chemical, microbiological, and sensory aspects of the resulting
cheese were assessed. Three replications have been completed.
2.7 Chemical composition
Fortified UF soft cheese was analyzed for TS, fat, protein level, and pH value according to (Association
of Official Analytical Chemists, 2005).

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 4/11
2.8 Microbiological analysis
Under aseptic conditions, 10 g of UF-soft cheese samples were transferred to a sterilized Hoon porcelain
and homogenized in 10 mL of sterile (20%) sodium citrate solution. The dilutions were made by adding (80
ml) sterile saline solution to make the appropriate dilutions required for microbiological tests. Thus, L.
acidophilus was counted on MRS agar. Plates were incubated at 37 °C for 48 hours, submerged. Besides,
they form shallow colonies and their colony patterns may be compact or pinnate and are small and opaque
and these colonies were taken as L. acidophilus. Streptococci counts were enumerated on M17 agar. The
plates were incubated at 30 oC under aerobic condition for 72 h.
2.9 Sensory assessment
The sensory evaluation was carried out by 20 members of staff in the Dairy and Food Science and
Technology departments, Faculty of Agriculture, Fayoum University (twelve women and eight men, aged
between 24 and 52 years), to evaluate the flavour, appearance, body, and texture of cheese samples. Name
of the sensory test applied: Difference Tests (Scoring). The soft cheese scorecard was created based on the
score offered by (Farrag et al., 2017). The assessors gave the cheese a score of 50 points for flavour, 35 points
for body and texture, and 35 points for appearance (out of 15 points).
2.10 Analytical statistical
The mean of at least three replicates is used to calculate the results. All the collected data was statistically
analyzed using General Linear Models (GLM) in SPSS (1999) for Windows, version 19. Duncan's multiple
range test was used to examine variable differences among treatments, storage period, and the interaction
mean at p ≤ 0.05 level of significance (Duncan, 1955).
3. Results and discussion
3.1 Mandarin peel powder and its total phenolic content
Fruits, vegetables, and derived drinks have been linked to the antioxidant activity of polyphenolic substances
(Costanzo et al., 2022). The TPC of MPP and extracts of different solvents are shown in Table 1. The TPC of
powder was 7.25 (mg/g sample) as gallic acid appeared to be highly significant compared to the extractions
6.98, 6.75, 6.64, 5.59, 4.88 in methanol, water, ethanol, chloroform, and acetone, respectively. (Zhang et al.,
2018) showed that the TPC in the peels of mandarin (C. reticulata Blanco) ranged from 1.09 to 34.03 mg (gallic
acid equivalent (GAE)) g–1 DW for peels. This difference was probably the result of plant variety and planting
conditions of the fruit used in our research. The loss of water content from the peel reduces the weight of the
material for simpler handling and storage, minimizes the danger of bacterial growth, and allows for more
efficient extraction (Hegde et al., 2015). Oven drying uses heat energy to swiftly remove moisture from samples
while preserving phytochemicals. Surface contact between samples and extraction solvents is increased when
samples are ground into smaller particle sizes (Azwanida, 2015). For a pre-extraction procedure with mandarin
peels, this investigation validated oven drying at 50 °C followed by grinding.
Table 1. Mandarin peel powder (MPP) and total phenolic content (TPC).
Sample type
TPC (mg/g sample) as gallic acid
Powder
7.25 ± 0.37 a
Extract by 80% Methanol
Chloroform
5.59 ± 0.13 d
dissolved in DMS
Water
6.75 ± 0.17 c
dissolved in DMS
Methanol
6.98 ± 0.48 b
dissolved in DMS
Ethanol
6.64 ± 0.30 c
dissolved in DMS
Acetone
4.88 ± 0.21e
dissolved in DMS
a, b, c, d, e, f: means having different small superscripts are significantly different (p ≤ 0.05). Means ± standard deviations. DMS: dimethyl sulfoxide.

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 5/11
3.2 Antioxidant activity
Radical scavenging activities of MPP and solvent extracts were measured to examine the antioxidant
activities (data in Figure 1). The free radical scavenging of mandarin powder and methanol extracts of all
five concentrations 2, 4, 6, 8 and 10 were (33.58, 80, 88 and 93), (30, 55, 73, 85 and 90), respectively. Acetone
extraction, on the other hand, had the lowest free radical scavenging activity at concentrations of 16, 40, 55,
67, and 75, respectively. The antioxidant activity of powder and methanol extractions was higher than that
of water, chloroform, ethanol, and acetone extractions (Figure 1). According to (Spigno et al., 2007),
phenolic compounds are known to dissolve more readily in higher polarity liquids.
Figure 1. Antioxidant activity of mandarin peels powder (MPP) and its extracts using DPPH methods.
The antioxidant capacity of phenolic and flavonoid compounds in plants is the key contributor to the
unique biological actions in disease prevention and therapy, according to Dai & Mumper (2010). Data in
Table 2 show that MPP extractions, powder, and methanol extract have the highest percentage of
antioxidants, as they have lower IC50 values (3.60 and 4.78 mg/mL, respectively), followed by ethanol and
water extractions, with IC50values of 5.09 and 5.38 mg/mL, respectively. On the other hand, chloroform and
acetone extractions recorded the lowest antioxidant activity (5.97 and 6.08). Our findings support
Balaky et al. (2020) that the solvent extract qualities have a substantial impact on the antioxidant activity of
phenolic content. The antiradical powder (ARP) numbers differ from IC50 values in that the greater the IC50,
the lower the ARP, and vice versa because high ARP values imply high antioxidant efficiency.
Table 2. IC50 and antiradical powder (ARP) of MPP and extracts.
Extract
IC50
ARP
Powder
3.60 ± 0.16 e
0.278 ± 0.11a
Extract by 80% Methanol
Chloroform
5.97 ± 0.21a
0.168 ± 0.14e
dissolved in DMS
Water
5.38 ± 0.28 b
0.186 ± 0.31d
dissolved in DMS
Methanol
4.78 ± 0.18 d
0.209 ± 0.27b
dissolved in DMS
Ethanol
5.09 ± 0.30c
0.196 ± 0.28c
dissolved in DMS
Acetone
6.08 ± 0.28a
0.164 ± 0.16e
dissolved in DMS
a, b, c, d, e: means having different small superscripts are significantly different (p ≤ 0.05). Means ± standard deviations. DMS: dimethyl sulfoxide.
The antioxidant scavenging activity of UF soft cheese fortified with MMP was examined (Figure 2). The
inclusion of MPP had a significant impact on the inhibition activity. Cheese with 5% MPP (M3) treatment
showed the highest inhibition activity followed by Cheese with 3% MPP (M2) and Cheese with 1% MPP
(M1) compared with control samples (C) without any addition of MPP.

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 6/11
Figure 2. Antioxidant activity of mandarin peel powder (MPP) fortified UF soft cheese using DPPH methods. C:
control without MPP; M1: cheese with 1% MPP; M2 cheese with 3% MPP; M3: cheese with 5% MPP.
3.3 Antibacterial activity
The results in Table 3 revealed that MPE were potent antimicrobials against all tested microorganisms.
The methanol extract showed significantly high degree of inhibition than that done by other extracts. As can
be seen, methanol extract showed maximum antibacterial activity against E. coli, with maximum inhibition
zone diameter recorded at 14 mm and the lowest with B. cereus at 10 mm. No inhibition zone was observed
either by chloroform or acetone against bacteria species. The effectiveness of the extracts can be summarized
as methanol extract > ethanol extract > water extract of MPP. Shetty et al. (2016) demonstrated that ethanolic
extracts of citrus peel are more potent in antimicrobial activity than aqueous extracts.
The MIC and MBC against E. coli, B. cereus, and Staph. aureus were between different concentrations as
1024, 512, 256, 128, 64, 32, 16, and 8. The data about methanol extract is presented in Table 4. It can be seen
that the highest antibacterial activity was obtained with the methanol extract of mandarin peel against E. coli
and Staph. Aureus, seeing that they were recorded 16 and 32 from the MIC and MBC, respectively. Similar to
Cushnie & Lamb (2005), methanol extract has the highest antioxidants and antimicrobial activity. Balaky et al.
(2020) concluded that the phenolic compounds in citrus peels are responsible for the antimicrobial activity. The
antimicrobial activities of citrus fruits have been associated with flavonoids and phenols (Viuda-Martos et al.,
2008). Pavithra et al. (2009) demonstrated that the active ingredient responsible for the antimicrobial activity
of citrus peel oils is a monoterpene. The main factors for the antimicrobial ability of citrus peel oils are D-
limonene and linalool. Previous work revealed that the inhibitory effect of citrus peel essential oils is due to the
presence of linalool instead of limonene (Fisher & Phillips, 2006).
Table 3. Inhibition zones of mandarin peel extracts (MPE) against some foodborne pathogens and spoilage bacteria.
Extracts
E. coli
B. cereus
Staph. aureus
IZ (mm)
IZ (mm)
IZ (mm)
1-Acetone
-
-
-
2-Methanol
14.22 ± 0.16a
10.15 ± 0.08c
13.17 ± 0.14b
3-Water
7.14 ± 0.11e
3.09 ± 0.12g
4.12 ± 0.06f
4-Ethanol
8.11 ± 0.14d
4.20 ± 0.08f
3.21 ± 0.07g
5-Chloroform
-
-
-
Image
a, b, c, d, e, f, g: means having different small superscripts are significantly different (p ≤ 0.05). Means ± standard deviations.

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 7/11
Table 4. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of mandarin
peel methanol extract against bacteria strains.
Strain
MIC (µg mL -1)
MBC (µg mL-1)
E. coli
16
32
B. cereus
32
-
Staph. aureus
16
32
3.4 Microbiological characteristics of MPP- fortified UF cheese
Figure (3) presents the viability of Lactobacilli in UF cheese enriched with MPP throughout storage at
5°C. Thus, Lactobacilli log counts in the fresh sample ranged from 8.52 to 9.49 CFU/mL. The maximum
value was found from UF soft cheese that had been fortified with a 5% MPP treatment (M3). Zaki & Naeem
(2021) found that adding citrus peels to yoghurt drinks promotes the proliferation of bacteria. During 21 days
of storage, Lactobacilli viable counts in treatments with MPP were higher than in controls; this could be
related to the presence of MPP, which aided starter growth.
It is possible to deduce that the presence of MPP caused L. acidophilus to develop faster. Because these
treatments had the greatest viable counts both during and after storage, they were chosen. Despite this, all
treatments had high L. acidophilus levels. Even after 21 days of storage at 6±1 °C, acidophilus viable counts
exceeded 8 log CFU/g (Irkin et al., 2015). Fruit peels have prebiotic effects on lactic acid bacteria (LAB),
according to Dias et al. (2020). This result could be due to product enrichment in terms of phenolic
compounds and fiber content.
In the present study, there was an increase in Str. thermophilus counts on treatments, increasing the
additional level of MPP compared with the minor bacterial count observed in control (Figure 4). In
accordance, although mandarin peels have prebiotic actions, Dias et al. (2020) observed that high LAB count
could be found in fat and sugar-free yoghurt with 0.5% fruit peel powder incorporation.
Figure 3. Lactobacilli count of symbiotic UF soft cheese. C: control without MPP; M1: cheese with 1% MPP; M2
cheese with 3% MPP; M3: cheese with 5% MPP.
Figure 4. Streptococci count of symbiotic UF soft cheese. C: control without MPP; M1: cheese with 1% MPP; M2
cheese with 3% MPP; M3: cheese with 5% MPP.

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 8/11
3.5 The chemical composition MPP-fortified UF soft cheese
Data presented in Table 5 described the chemical composition of UF soft cheese fortified with MPP. The
inclusion of MPP had a significant impact on TS, which grew as the MPP ratio increased. In contrast, the
protein and fat contents were not affected (p ≤ 0.05) by the addition of MPP. The lowest values were noted
with control and treatments supplemented with 1%; it could be detected that TS content developed by the
additional level of MPP. So, this change is due to the high TS content in M2 and M3 treatments compared
with control and M1. This increase in TS could be attributed to the addition of MPP, which has a high TS
(protein 4.19%, fat 3.82%, moisture 9.5%, fiber 7.93%, carbohydrate 71.25%, and ash 3.31%). These results
agree with Ojha et al. (2016) who reported that TS in MPP relatively increases in dry matter.
Table 5. Chemical composition of symbiotic UF soft cheese.
Treatments
DM%
Fat%
TP%
C
36.51 ± 0.23
b
15.00 ± 0.50
a
13.86 ± 0.04
a
M1
36.68 ± 0.60
b
15.07 ± 0.21
a
13.88 ± 0.03
a
M2
37.07 ± 0.14
a
15.13 ± 0.25
a
13.89 ± 0.03
a
M3
37.11 ± 0.14
a
15.23 ± 0.25
a
13.90 ± 0.04
a
C: control without MPP; M1: cheese with 1% MPP; M2 cheese with 3% MPP; M3: cheese with 5% MPP. a, b: means having different small
superscripts are significantly different (p ≤ 0.05). Means ± standard deviations
Table 6 shows the titratable acidity (TA) (%) of symbiotic UF soft cheeses when fresh and after storage
(5 oC/21 days). The increases in TA of symbiotic UF soft cheese followed the opposite trend in pH, with the
TA (%) of symbiotic UF soft cheese being much more relevant than the control cheese, especially near the end
of the storage period. Furthermore, statistical analysis demonstrated that the storage length and degree of added
MPP at different treatments had a significant (p ≤ 0.05) impact on the TA of symbiotic UF soft cheeses. These
findings supported those of Dias et al. (2020), who discovered that raising TA and decreasing pH were
positively associated with fiber content in FPP (pineapple and orange peel powder). Symbiotic white soft
cheeses, on the other hand, manufactured with S. thermophilus and L. acidophilus (1:1) with an additional 5%
MPP had the greatest TA levels (2.45 percent) at the conclusion of the storage period. According to
(Rashidinejad et al., 2022), the development of acidity during storage is caused by the conversion of residual
lactose in cheese to lactic acid (LA) by the available microflora. Effat et al. (2012) and Ricci et al. (2019)
discovered that orange peel is a good matrix for LA fermentation since it allows diverse LAB to grow.
Table 6. Changes in acidity (%) and symbiotic UF soft cheese pH with mandarin peel powder (MPP) during storage.
Treatments
Acidity%
Storage period (day)
fresh
7
15
21
Treatment effect
C
0.49 ± 0.01
l
1.16 ± 0.06
i
1.29 ± 0.01
h
1.77 ± 0.04
e
1.19 ± 0.48
D
M1
0.72 ± 0.02k
1.50 ± 0.09g
1.50 ± 0.03g
2.05 ± 0.03c
1.44 ± 0.50C
M2
1.03 ± 0.03
j
1.61 ± 0.06
f
1.86 ± 0.03
d
2.21 ± 0.02
b
1.68 ± 0.46
B
M3
1.16 ± 0.02j
2.05 ± 0.02c
2.10 ± 0.01c
2.45 ± 0.04a
1.95 ± 0.64A
Storage effect
0.85 ± 0.27D
1.60 ± 0.34C
1.69 ± 0.33B
2.12 ± 0.26A
pH
C
5.98 ± 0.01a
5.55 ± 0.01c
5.41 ± 0.02d
4.93 ± 0.03i
5.47 ± 0.39A
M1
5.78 ± 0.02b
5.37 ± 0.01e
5.24 ± 0.03f
4.83 ± 0.02j
5.30 ± 0.36B
M2
5.54 ± 0.01c
5.10 ± 0.03g
4.91 ± 0.02i
4.53 ± 0.03k
5.02 ± 0.38C
M3
5.43 ± 0.01
d
4.98 ± 0.02
h
4.81 ± 0.05
j
4.35 ± 0.02
l
4.89 ± 0.41
D
Storage effect
5.68 ± 0.22A
5.25 ± 0.23B
5.09 ± 0.26C
4.66 ± 0.24D
-
C: control without MPP; M1: cheese with 1% MPP; M2 cheese with 3% MPP; M3: cheese with 5% MPP. A, B, C and D: means within the
treatments and storage period effect having different capital superscripts are significantly different (p ≤ 0.05). a, b, c, d. e. f. g, h. i., j. k, l : means having
different small superscripts are significantly different (p ≤ 0.05). Means ± standard deviations.

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 9/11
3.6 Consumer acceptance of symbiotic UF soft cheese using peel powder
There was a substantial change in appearance, flavour, body, and texture between control (C) and MPP
added (M1, M2, M3) symbiotic UF soft cheese in this study. However, a sample containing 5% MPP showed
a much lower preference for sensory evaluation (Table 7). The removal of a slightly bitter MPP taste was
detected in the first week of the trial. This unusual flavour was favored by several customers over the standard
cheese. Because high fiber content affects the fundamental cheese flavour, 5 percent MPP added UF soft
cheese had the lowest total scores following appearance, flavour, and body and texture characteristics.
However, a 1% MPP mixture mixed with cheese gives the highest total score (Table 8). (Dias et al., 2020)
discovered that adding a 0.5% FPP mixture (pineapple and orange peel powder) to fat and sugar-free probiotic
yoghurts can help preserve texture and boost customer acceptability.
Table 7. Changes in acidity (%) and symbiotic UF soft cheese pH with mandarin peel powder (MPP) during storage.
Treatments
Acidity%
Storage period (day)
Fresh
7
15
21
Treatment effect
C
0.49 ± 0.010
l
1.16 ± 0.055
i
1.29 ± 0.006
h
1.77 ± 0.035
e
1.19 ± 0.479
D
M1
0.72 ± 0.018
k
1.50 ± 0.090
g
1.50 ± 0.025
g
2.05 ± 0.025
c
1.44 ± 0.497
C
M2
1.03 ± 0.026
j
1.61 ± 0.055
f
1.86 ± 0.026
d
2.21 ± 0.015
b
1.68 ± 0.457
B
M3
1.16 ± 0.017
j
2.05 ± 0.020
c
2.10 ± 0.010
c
2.45 ± 0.035
a
1.95 ± 0.635
A
Storage effect
0.85 ± 0.274
D
1.60 ± 0.336
C
1.69 ± 0.327
B
2.12 ± 0.256
A
pH
C
5.98 ± 0.010
a
5.55 ± 0.010
c
5.41 ± 0.015
d
4.93 ± 0.025i
5.47 ± 0.
A
M1
5.78 ± 0.020
b
5.37 ± 0.010e
5.24 ± 0.025
f
4.83 ± 0.021j
5.30 ± 0.
B
M2
5.54 ± 0.012c
5.10 ± 0.031
g
4.91 ± 0.020i
4.53 ± 0.025k
5.02 ± 0.
C
M3
5.43 ± 0.006d
4.98 ± 0.020h
4.81 ± 0.050
j
4.35 ± 0.015l
4.89 ± 0.
D
Storage effect
5.68 ± 0.223A
5.25 ± 0.234B
5.09 ± 0.256C
4.66 ± 0.242D
C: control without MPP; M1: cheese with 1% MPP; M2 cheese with 3% MPP; M3: cheese with 5% MPP. Values with different superscript
letters in a column are significantly different (p ≤ 0.05).
Table 8. Sensory evaluation of symbiotic soft cheese during the storage period.
Treatments Storage period
(days)
Organoleptic properties
Flavour (50) Body and
texture (35)
Appearance
(15 points)
Total (100)
C
Fresh
47.56
e
34.11
c
14.38
bc
96.05
d
7
47.67
e
32.83
d
14.40
bc
94.90
e
15
47.55
e
33.81
d
14.54
b
95.90
d
21
45.71
i
32.86
f
14.14
d
92.71
h
M1
Fresh
48.11d
34.44b
14.83a
96.93c
7
49.17
a
35.00
a
14.70a
a
99.00
a
15
48.64b
34.57b
14.38bc
97.52b
21
48.33
c
34.18
c
14.33
c
97.23
bc
M2
Fresh
46.6
g
33.22
e
13.75
e
93.57
g
7
47.00
f
33.77
d
13.5
f
94.27
f
15
46.27
h
33.27
e
14.10
d
93.64
g
21
46.86
f
33.00
ef
13.43
f
93.29
g
M3
Fresh
43.33
k
31.25
g
13.13
g
87.71
j
7
43.50
k
31.17
g
11.83
j
86.50
k
15
44.55
j
31.36
g
12.64i
88.55
i
21
44.43j
31.42g
12.85h
88.70i
C: control without MPP; M1: cheese with 1% MPP; M2: cheese with 3% MPP; M3: cheese with 5% MPP. a, b, c, d. e. f. g, h. i., j. k, l: means having
different small superscripts significantly different (p ≤ 0.05). Means ± standard deviations.

The assessment of the antioxidant and antibacterial activity of Mandarin peel powder and their impact on the symbiotic soft cheese quality
Ebid, W. M. A. et al.
Braz. J. Food Technol., Campinas, v. 27, e2023088, 2024 | https://doi.org/10.1590/1981-6723.08823 10/11
4 Conclusions
The mandarin peel is a promising important part of the mandarin fruit, it has many functional effects. MPP
extracts have antioxidant and antibacterial activity. Thus, Probiotic UF-white soft cheese can be fortified
with MPP. Cheese fortified with MPP gained higher antioxidant properties, viability, total scores and got
better flavor, body and texture and acceptability. MPP can be considered beneficial in the production of
healthy and functional white soft cheese.
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Funding: None.
Received: July 04, 2023; Accepted: Aug. 05, 2024
Associate Editor: Eliana Paula Ribeiro.