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Quality Characteristics of Yoghurt Enriched with Spirulina Powder

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Abstract

Spirulina is a rich source of nutrients viz., essential amino acids, essential fatty acids, carotenoids, minerals and vitamins and thus can potentially represent an important staple in the human diet. The present work focuses on enrichment of yoghurt with spirulina with its addition in concentrations of 0.1, 0.2, 0.3 and 0.5 per cent. With increase in level of spirulina there was an increase in protein, fat and iron content. Higher curd strength was observed with increased level of spirulina percentage. Increase in acidity and reduction in setting time was observed with increase in sprirulina concentration. It also gave natural light green colour to yoghurt enriched with it. Yoghurt prepared with 0.3 per cent spirulina had comparable scores for sensory parameters like colour and appearance, body and texture, whey separation, flavour and overall acceptability with that of control. Through viability of yoghurt culture declined during storage, viability of yoghurt cultures in yoghurt prepared with 0.3 per cent spirulina was higher when compared to control during storage at 4°C.
Quality Characteristics of Yoghurt Enriched with Spirulina Powder
PRIYANKA MALIK, C. KEMPANNA, NARASIMHA MURTHY AND ANJUM
Department of Dairy Chemistry, Dairy Science College, KVAFSU, Hebbal, Bangalore - 560 024
ABSTRACT
Spirulina is a rich source of nutrients viz., essential amino acids, essential fatty acids, carotenoids, minerals
and vitamins and thus can potentially represent an important staple in the human diet. The present work focuses
on enrichment of yoghurt with spirulina with its addition in concentrations of 0.1, 0.2, 0.3 and 0.5 per cent. With
increase in level of spirulina there was an increase in protein, fat and iron content. Higher curd strength was
observed with increased level of spirulina percentage. Increase in acidity and reduction in setting time was
observed with increase in sprirulina concentration. It also gave natural light green colour to yoghurt enriched
with it. Yoghurt prepared with 0.3 per cent spirulina had comparable scores for sensory parameters like colour
and appearance, body and texture, whey separation, flavour and overall acceptability with that of control. Through
viability of yoghurt culture declined during storage, viability of yoghurt cultures in yoghurt prepared with 0.3 per
cent spirulina was higher when compared to control during storage at 4°C.
Mysore J. Agric, Sci., 47 (2) : 354-359, 2013
NUTRITIONAL and physico-chemical attributes are the
most important deciding factor when consumers
purchase dairy products. The popularity of yoghurt
is due to its pleasant favour, thick creamy consistency
and its reputation as food associated with promoting
good health (Domagla, 2005). Fermented milks
enriched with minerals, proteins and essential fatty
acids such as gamma linolenic acid, vitamins and
minerals (Perez et al., 2007). It also gives natural
colour to yoghurt enriched with it. Spirulina is a rich
source of nutrients viz., essential amino acids, essential
fatty acids, carotenoids, minerals and vitamins and thus
can potentially represent an ·important staple in the
human diet. The present work focuses on enrichment
of yoghurt with spirulina with its addition in
concentrations of 0.1, 0.2, 0.3 and 0.5 per cent.
MATERIAL AND METHODS
Parry’s organic spirulina, skim milk powder
(SMP) of ‘SAGAR’ brand manufactured by Mother
Dairy, VRBA; MEA; Rogosa agar and YGA of Hi
media, stabilizer (Sodium alginate) and emulsifier
(GMS) were procured from local market. Milk and
cream was procured from student experimental dairy
plant, Dairy Science College, Bangalore. Starter
culture viz., Streptococcus thermophilus and
Lactobacillus deibruckii sub spp buigaricus were
procured from Department of Dairy Microbiology.,
Dairy Science College, Bangalore. Chemicals and
reagents used were of AR grade.
Preparation of spirulina solution for
incorporation into yoghurt: Spirulina solution was
dispersed in milk at 0.1, 0.2, 0.3 and 0.5 per cent levels
for yoghurt preparation before homogenization.
Desired amount of spirulina powder was dissolved in
15 ml distilled water at 25°C and mixed with the help
of magnetic stirrer for 20 min. This solution was kept
for hydration for overnight at refrigeration temperature
for hydration. Just before using for product
preparation, this was remixed for 15 minutes usmg a
magnetic stirrer.
Preparation of yoghurt : The control yoghurt
was prepared according to the method of Lucey (2004).
Fresh milk was standardized to 4.5 per cent fat and
9.5 per cent solids not fat (SNF) using cream and SMP.
Spirulina powder was added to milk at the rate of 0.1,
0.2, 0.3 and 0.5 per cent in the test yoghurt preparation
before homogenization. The mix was pre-heated to
65°C for 10 min and homogenized in two stages by
maintaining the pressure of 2500 kg / cm2 in first stage
and 500 kg / cm2 in second stage. The samples were
heated to 90°C for 30 min and cooled to 42°C. The
culture was added at the rate of 2 per cent level and
incubated at 42°C for setting of curd.
Sensory analysis of yoghurt : A panel of four
judges evaluated the control and modified products
of yoghurt. The product was judged on the basis of
standard score card for firmness. whey separation,
body and texture, taste and flavour for yoghurt.
Hardness : The hardness of the samples was
measured using a cone Penetrometer by selecting a
standard cone weighing 10.38 g which penetrates in
in to product in 5 sec. The extent of penetration was
noted and expressed as millimetre of penetration.
Reading was recorded at 3 different spots and average
values were noted (Dave and Sah, 1998).
Syneresis : Yoghurt (35 g) was centrifuged at
1100 rpm for 10 min at 5°C. The clear supernatant
was poured off, weighed and recorded as syneresis
(Gaston et al., 2007).
Chemical analysis : Fat (Gerber method), total
solids (Gravimetric method), acidity and protein were
estimated as per ISI : SP 18 (part XI, 1981). Iron
was estimated as per the procedure of Ranganna, 2005.
Total viable count for yoghurt cultures : The
microbiological analysis of yoghurt samples were
carried out for total viable count for total count and I.
bulfaricus by using media yeast glucose agar (YGA)
and Acetate agar, respectively with incubation
temperature of 37°C for 24 to 42 hr and 37°C for 3
days at anaerobic conditions, respectively. The total
viable count of yoghurt was analyzed by following
the procedure of Salvador and Fisczman (2004).
Statiscal analysis : Average scores secured by
experimental samples were compared with those of
the control samples and the results were analyzed by
using completely randomized design for one way
ANOVA by using SPSS-10 software.
RESULTS AND DISCUSSION
The average composition of spirulina used in this
study was 63, 22, 6, 8 and 1 per cent for protein,
carbohydrate, fat, minerals and moisture, respectively.
Gross composition of yoghurt enriched with
spirulina: Spirulina can be used for supplementing
quality and sensory characteristics of yoghurt.
Fermented milks enriched with vitamins, proteins,
essential fatty acids and trace elements of natural origin
can be manufactured using Cyanobacteria (Varga and
Szigeti, 1998).
The effect of enrichment of yoghurt with
spirulina on gross composition of yoghurt (Table I)
indicated that with increase in enrichment level from
0 to 0.5 per cent, there was significant increase in
protein from 3.80 to 4.17 per cent, total solids from
TABLE I
Gross composition of yoghurt enriched with spirulina
0 17.85 3.80 8.70 4.47 0.84 0.04
0.1 18.12 3.92 8.72 4.53 0.85 0.10
0.2 18.36 4.00 8.74 4.60 0.86 0.16
0.3 18.55 4.05 8.77 4.66 0.86 0.21
0.5 18.96 4.17 8.80 4.79 0.88 0.32
Spirulina
added (%)
Chemical composition (%)
Total solids Protein Carbon
hydrate
Fat Ash Iron (mg /
100 g)
ANOVA SUMMARY
S.Em ±. 0.058 0.0025 0.01 0.0009 0.0005 0.0001
F Value 9.29 23.17 0.47 50.83 0.65 344.4
CD 0.44 0.09 NS 0.05 NS 0.02
All values are average of three trials NS : Non significant at 5% level
QUALITY CHARACTERISTICS OF YOGHURT ENRICHED WITH SPIRULINA POWDER 355
17.85 to 18.96 per cent and iron content from 0.04 to
0.32 mg / 100 g. Spirulina is known to be a rich source
of protein and minerals. The compositional change of
yoghurt may be attributed to the inherent composition
of spirulina. However, the increase in carbohydrate
and ash content in spirulina enriched yoghurt was
found to be non significant.
Milk being poor source of iron, the enrichment
with spirulina had beneficial impact on enhancing the
iron content of yoghurt. Henrikson (2009) reported
the very high iron content of spirulina should be
stressed because iron deficiencies (anemia) are
widespread, particularly in pregnant women and
children, and good sources in food are rare. As a
comparison, iron supplements given in the form of
ferrous sulpate can pose a toxicity problem and often
cause diarrohea. Cereals are rich in phytic acids and
phosphatic polymers, which sharply limits the bio-
availability of the iron they contain. In the case of
spirulina, iron bio-availability has been demonstrated
both in rats and in humans without any side effects.
Thus, enrichment of yoghurt with spirulina has
nutritional beneficial effect in fortifying iron content
of enriched yoghurt.
Setting time : The effect of enrichment with
spirulina on setting time was studied (Table II). The
results show that, setting time decreased from 250
minutes in control yoghurt to 180 minutes in 0.5 per
cent spirulina incorporated yoghurt. This can be
accounted for the fact that the spirulina biomass is of
alkaline character and is capable of increasing growht
of dairy starter culture and simultaneously the acid
production, during fermentation (Varga et al., 2002
and Perez et al., 2007).
Acidity and pH: The results indicate that, with
increase in incorporation of spirulina from 0 to 0.5
per cent resulted in increase in acidity from 0.72 to
0.81 per cent lactic acid (LA) and decrease in
corresponding pH from 4.3 to 4.08 (Table II). As a
result of increasing the level of SNF in milk, the titrable
acidity of milk increased due to buffering action of
the additional proteins, phosphates, citrates, lactates
and other miscellaneous milk constituents (Walstra and
Jenness, 1984) and this function can lead to reduced
gel formation time. However, the values of both acidity
and pH of yoghurt at all levels of spirulina
incorporated were within BIS standards. The results
were in accordance with Szigeti et al. (2003) who
TABLE II
Effect of enrichment with spirulina on physical and rheological properties of yoghurt
0 250 4/3 0.72 292.52 1.4
0.1 235 4.25 0.72 285.51 1.2
0.2 215 4.15 0.73 278.92 1.0
0.3 200 4.10 0.74 271.24 1.4
0.5 180 4.08 0.81 265.57 2.4
Spirulina
added (%)
Setting time
(min)
pH Acidity
(% LA)
Penetration value
(mm / 5 sec)
Syneresis
(ml /35 g)
ANOVA SUMMARY
S.Em ± 25 0.0025 0.0001 0.05 0.01
F Value 92.1 10.96 42.90 1396.356 87.6
CD 9.10 0.09 0.02 0.41 0.18
All values are average of three trials NS : Non significant at 5% level
356 PRIYANKA MALIK et al.
reported that cyanobacteria additive significantly
increased the acid production due to increased
proliferation rate of certain thermophilic dairy industry
cultures.
Penetration value: The effect of enrichment of
yoghurt with spirulina on curd strength and syneresis
was studied (Table II). Increase in level of
incorporation of spirulina from 0 to 0.5 per cent
resulted in decreased penetration value from 292.52
to 265.57 (mm / 5 sec) indicating increase in curd
strength of yoghurt. The increase in curd strength with
increase in level of spirulina could be attributed to
the higher protein content of spirulina and acidification
by lactic cultures which strengthen the 3-dimensional
network by entrapping water. The important reason
for decrease in penetration value could be attributed
to enhanced protein-protein interaction which resulted
in formation of firm gel (Bhatia et al., 2004).
Syneresis: Syneresis which is nothing but
wheying off is a common problem in the fermented
milk products like yoghurt and dahi (Shukla and Jain,
1991). Increase in level of incorporating spirulina up
to 0.2 per cent decreased syneresis in yoghurt which
increased rapidly in the product at higher than 0.2 per
cent of spirulina incorporation (Table II). The
decreased syneresis with increase in level of spirulina
could be attributed to the greater water binding
capacity of 1.45 g / g of protein spirulina (Robinson
et al., 2000). However, increased syneresis beyond 0.2
per cent levels of spirulina incorporation may be
attributed to higher acid production and proteolysis
which resulted in higher fermentation.
Sensory characteristics: Sensory characteristic
of yoghurt is an important parameter in the consumer
acceptance of the product (Table III). The body and
texture colour and appearance, flavour and whey
separation significantly influences the overall
acceptability of yoghurt. Overall acceptability of
yoghurt increased with increased levels of enrichment
with spirulina from 0.1 up to 0.3 per cent level then
decreases thereafter with increase in the level of
incorporation upto 0.5 per cent. The scores obtained
for yoghurt with 0.2 per cent level of spirulina for
flavour, body and texture and whey separation are
comparable to that of control. The scores obtained
for yoghurt with 0.3 per cent level of spirulina
enrichment were higher than that of control. This may
be attributed to the functionality of spirulina. The
experimental product recorded higher scores for
flavour, body and texture and color and appearance
when compared to control yoghurt. The product
TABLE III
Sensory characteristics of yoghurt enriched with spirulina
0 27.40 18.90 9.20 37.10 92.70
0.1 27.80 16.60 9.30 36.20 89.90
0.2 27.70 18.20 9.40 37.10 92.50
0.3 27.70 19.10 9.20 38.10 94.10
0.5 26.70 14.70 8.50 34.30 84.30
Spirulina
added (%)
Body and
texture
(30)
Colour and
appearance
(20)
Whey
separation
(10)
Flavour
(40) Overall
accceptability
ANOVA SUMMARY
S.Em ± 1 0.48 0.04 1 7.29
F Value 0.62 21.99 9.84 6.20 6.39
CD NS 1.26 0.36 1.82 4.91
All values are average of three trials NS : Non Significant at 5% level
QUALITY CHARACTERISTICS OF YOGHURT ENRICHED WITH SPIRULINA POWDER 357
obtained had a light green (pista) colour which was
well accepted by panel of judges. The lower score at
0.1 per cent level when compared to control may be
attributed to dull colour and appearance and less acidic
flavour which is essential for acceptability for yoghurt.
The decrease in score with increase in level of
incorporation at 0.5 per cent level is mainly due to
bland oily flavour, higher whey separation due to
increased acidity and intense green colour. These might
be the causes for decreased overall acceptability of
the product with 0.1 and 0.5 per cent level of
enrichment with spirulina. Therefore, it can be
concluded that yoghurt enriched with spirulina at 0.3
per cent level received better scores with respect to
all attributes and this was adjudged to be superior
product when compared to other treated yoghurt
products.
Viability of yoghurt culture during storage at
refrigeration temperature (5°C±1): The effect of
enrichment of yoghurt with 0.3 per cent spirulina
biomass on viability of yoghurt culture during storage
is presented (Table IV). At regular interval of 5 days,
these products were analyzed for viability of
Streptococcus thermophilus and Lactobacillus
delbrueckii Sp bulgaricus. During initial stage, viable
count of S. thermophilus for control and spirulina
yoghurt were 7.57 and 7.87, respectively. With
progress of storage up to 15 days the viable count
decreased to 5.08 and 6.87 for control and spirulina
yoghurt, respectively. In case of I. bulgaricus the
initial stage viable count for control and Spirulina
yoghurt were 7.42 and 7.69, respectively. With
progress of storage up to 15 days the viable count
decreased to 5.30 and 6.71 for control and spirulina
yoghurt, respectively. From this observation it is
revealed that the viability of S. theromophilus is more
when compared to I. bulgaricus. With progress in
storage period, the viability of yoghurt culture
decreased, which could be attributed to increased
acidity during storage period. Similar results were
observed by Laye et al. (1993).
However, viability of spirulina yoghurt was
higher when compared to control yoghurt for both S.
thermophilus and L. bulgaricus throughout the storage
period. Spirulina is known to have beneficial influence
on the survival of the starter bacterial culture owing
to its high protein, essential fatty acids such as gamma
linolenic acid, vitamins and minerals (Perez et al.,
2007). Similar results were observed by Varga et al.
(2002) who reported that spirulina positively
influenced the survival of ABT starter bacteria
regardless of storage temperature.
REFERENCES
BHATIA, K. L., KUMAR, A. AND CHAUHAN, A. K., 2004,
Gelling properties of whey protein concentrates and
its industrial applications. Ind. Dairyman, 56 : 61-
65.
DAVE, R. I. AND SHAH, 1998, Ingredient supplementation,
effects on viability of prebiotic bacteria in yoghurt.
J. Dairy Sci., 81 : 2804-2816.
TABLE IV
Effect of enrichment with spirulina on viability of yoghurt culture during storage at 5 °C
0 7.57 7.87 NS 7.42 7.69 NS
5 6.92 7.59 6.90 7.05
10 6.51 7.04 6.21 6.88
15 5.98 6.87 5.30 6.71
CD (P<0.05) NS NS
Number of days
All values are average of three trials NS : Non Significant at 5% level
S. thermophilus L. Bulgaricus
358 PRIYANKA MALIK et al.
DOMAGLA, J., 2005, Texture of yoghurt and bio-yoghurt
from goat’s milk depending on stater culture type :
J. Dairy Sci., 81 : 2804-2816.
GASTON, A., DENISSE, G., CECILIA, P., GABRIELA, R., NADIA,
S., PATRICIA, L. AND A DRIANA, G., 2007, Influence of
gelation and starch on the instrumental and sensory
texture of stirred yoghurt. Int. J. Dairy Technol.,
60 : 263-269.
HENRIKSON, R., 2009, Earth food spirulina. Ronore
Enterprises Inc., Hana, Maui, Hawaii.
ISI SP. IS (Part XI), 1981, ISI handbook of food analysis.
Part XI Dairy Products. Indian Standards Institute,
Manak Bhavan, New Delhi, 167-173.
LAYE , I., FITZGERALD, G. F., UNIACKE LOWE, T., DALY, C. AND
FOX, P. F., 1993, The contribution of lacto-coccus
starter protenases to proteolysis in cheddar cheese
during ripening. Int. Dairy J. 76 : 2455-2467.
LUCCY, J. A., 2004, Cultured dairy Products - An overview
of their gelation and texture properties. Int. J. dairy
Technol., 57 (2-3) : 77-84.
PEREZ, K. I., GUARENTI, C., BORTELIL, T. E., COSTA JAV E AND
COLLA, L. M., 2007, Effect of adding dry biomass of
the spirulina platensis to yogurt on the survival of
lactic acid bacteria during refrigerated stogie,
18 (1) : 77-82.
RANGANNA, S., 2005, Handbook of Analysis and Qualiity
Control for Fruit and Vegetable Products, 2nd edition.
Tata Mc. Graw-Hill Publishing Co. Ltd., New Delhi.
ROBINSON, R. K., CARL, A., BAT T AND PRADIP, D. PATEL, 2000,
Encyclopedia of food microbiology In : Single - Cell
Protein / The algae. Academic press. A Harcourt
Sci. and Tech. Company. 3 : 2025-2026.
SALVADOR, A. AND FISZMAN, S. M., 2004, Texture and
sensory characteristics of whole and skimmed
flavoured set yoghurt during long storage. J. Dairy
Sci., 87 : 4033-4041.
SHUKLA, F. C. AND JAIN, S. C., 1991, Effects of additives
on the quality of yoghurt, Ind. J. Dairy Sci., 44.
SZIGETI, J., VARGA, L. AND KRASZ, A., 2003, Some
possibilities for procution of some longer life
functional sour diary products. Tejgazdasag, 1 (2):
190-210.
VARGA, L. AND SZIGETI, J., 1998, Microbial changes in
natural and algal yoghurt during storage. Acta
Aliment. Hung., 27 : 127-135.
VARGA, L., SZIGETI, J., COVACS, R., FOLDS, T. AND BUTY, S.,
2002, Influence of spirulina platensis biomass on
microflora of ferment ABT milks during storage. J.
Dairy Sci. 85 : 1031-1038.
WALSTRA, P. AND JENNESS, R., 1984, In Dairy Chemistry
and Physics, John Wiley and Sons, New York.
QUALITY CHARACTERISTICS OF YOGHURT ENRICHED WITH SPIRULINA POWDER 359
(Received : September, 2012 Accepted : April, 2013)
... It contains 70% protein and is a rich source for essential fatty acids, amino acids, minerals, and vitamins, (Mosulishvili et al., 2004). Fortification of yoghurt with spirulina is beneficial in improving the iron content of yoghurt, especially milk is a poor iron source (Malik et al., 2013). The aim of the present study is to prepare freeze-dried yoghurt and investigate its effects with addition of some additives (whey protein concentrate, modified starch, and spirulina powder) on the physico-chemical, microbiological, texture, microstructure and sensory properties. ...
... Addition of 0.5% SP to yoghurt increased fracture, hardness, cohesiveness, springiness, gumminess, and chewiness in both fresh and rehydrated yoghurts as well as revealed the highest penetration force among all yoghurts. These results agree with those of Malik et al. (2013) who found that incorporation of 0.5 % spirulina increased penetration force indicating increase of strength of yoghurt curd. The increase of curd strength upon incorporation of spirulina could be attributed to the high protein content of spirulina. ...
... Viability of total lactic acid bacteria in spirulina yoghurt was higher when compared to the other yoghurt types for both Lactobacilli and Streptococci. The current results are similar to those observed by Varga et al. (2002) and Malik et al. (2013) who found that spirulina had a positive effect on the survival of yoghurt starter bacteria. Spirulina have a positive effect on the survival of the lactic acid bacteria due to high contents of protein, vitamins, minerals and essential fatty acids especially gamma linolenic acid in spirulina (Perez et al., 2007). ...
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... Addition of 0.5% SP to yoghurt increased fracture, hardness, cohesiveness, springiness, gumminess, and chewiness in both fresh and rehydrated yoghurts as well as revealed the highest penetration force among all yoghurts. These results agree with those of Malik et al. (2013) who found that incorporation of 0.5 % spirulina increased penetration force indicating increase of strength of yoghurt curd. The increase of curd strength upon incorporation of spirulina could be attributed to the high protein content of spirulina. ...
... Viability of total lactic acid bacteria in spirulina yoghurt was higher when compared to the other yoghurt types for both Lactobacilli and Streptococci. The current results are similar to those observed by Varga et al. (2002) and Malik et al. (2013) who found that spirulina had a positive effect on the survival of yoghurt starter bacteria. Spirulina have a positive effect on the survival of the lactic acid bacteria due to high contents of protein, vitamins, minerals and essential fatty acids especially gamma linolenic acid in spirulina (Perez et al., 2007). ...
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... While the protein content of yoghurt without Spirulina was 28.98 g/100 g DM, the protein content of SY-0.5, SY-1.0 and SY-1.5 yoghurts colored with Spirulina were 29.25, 29.79, and 29.90 g/100 g DM, respectively. Similarly, studies have shown that increase in Spirulina ratio also increases the total solid and protein content of yoghurt (Bchir et al., 2019;Malik et al., 2013). The ash content decreased to 4.22 g/100 g DM in SY-1.0 yoghurt and increased to 5.35 g/100 g DM in SY-1.5 yoghurt, although there was no significant difference (p > .05) in control (4.71 g/100 g DM) and SY-0.5 (4.75 g/100 g DM) yoghurts. ...
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Texture of yoghurt and bio-yoghurt from goat's milk depending on stater culture type
  • J Domagla
DOMAGLA, J., 2005, Texture of yoghurt and bio-yoghurt from goat's milk depending on stater culture type : J. Dairy Sci., 81 : 2804-2816.