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Improvement of the physical and oxidative stability characteristics of ice cream through interesterified Moringa oleifera oil.

Introduction

Milk fat contains plenty of atherogenic fatty acids which have a great deal of contribution in the enhancement of harmful LDL cholesterol. In addition to the saturated fatty acids, milk fat also contains higher extent of the dietary cholesterol; these factors make it the first choice of criticism for the nutritionists and dieticians (Williams, 2000). About 44% of the US population has shown negative opinion against the milk and dairy products particularly, fat rich dairy products (Hansel et al., 2007; Honda et al., 2007). The increased rate of mortalities from cardiovascular disease has led to the development of large number of modifications and replacement strategies in milk and dairy products. Partial replacement of milk fat with vegetable oils in ice cream consequences in weak body and lower melting resistance (Nadeem et al., 2010). This problem can be ameliorated by using lipids having higher melting points and melting resistance as extent of saturated fatty acids and melting points are usually correlated with each other.

Interesterification is an effective way to increase the slip melting point and solid fat content of vegetable oils without generation of undesirable trans isomers (Osman and Idris, 1999).

Moringa oleifera is widely grown in tropics and quality of its oil is almost similar to olive oil (Mohammed et al., 2003). Melting point of M. oleifera oil can be substantially increased through the random rearrangement of esters (Nadeem et al., 2012). Interesterified M. oleifera oil can fulfill the above mentioned quality and functionality characteristics simultaneously (Nadeem et al., 2012). The oil content of seeds ranges between 30-40%, oil is edible and rich in monounsaturated fatty acids (Tsakinis et al., 1998). Moringa oleifera oil improved the oxidative stability of vegetable oils and butter oil (Nadeem et al., 2013b).

The potential role of M. oleifera oil on the physical characteristics and oxidative stability of ice cream has not been studied so far. This study and aimed to evaluate the suitability of interesterified M. oleifera oil to partially replace milk fat in the formulation of functional ice cream. Some physicochemical, sensory and oxidative stability characteristics were observed to find out the suitability of chemically modified M. oleifera oil in blends with milk fat.

Materials and Methods

Chemical interesterification. M. oleifera oil was extracted by laboratory scale expeller, oil was stored in clean and dry pet bottles, sealed and stored at -18[degrees]C till further usage. Melting point of interesterified M. oleifera oil and milk fat was 19.8 and 35.2[degrees]C. Chemical interesterification of M. oleifera oil was performed to improve the melting resistance of ice cream. Samples were dehydrated in a flask, under reduced pressure, fitted with a vacuum pump in a water bath at 95[degrees]C. The portions were mixed with 0.2% (w/w) of sodium methylate. Interesterification reaction was performed under reduced pressure at 70[degrees]C in a 1000 mL stoppered flask in a water bath with constant agitation for 1 h. To stop the interesterification reaction, 5 mL distilled water was added. Treated blend was washed with hot water twice for the complete removal of catalyst (Sreenivasan, 1978). After rearrangement reaction, melting point of M. oleifera oil was 35.6[degrees]C.

Experimental plan. Milk fat was partially replaced with interesterified M. oleifera oil at 10,20 and 30% levels ([T.sub.1], [T.sub.2], [T.sub.3], respectively). The formulation of control comprised of 10% milk fat, 11%MSNF, 15% sucrose, 0.5%cremodan with no added colour and flavour.

Analysis. Fat was extracted from ice cream by following the recommended method of AOAC (1997). Fatty acids were analysed as fatty acid methyl esters using sodium methylate as transesterifying agent (Qian, 2003). Fatty acid methyl esters were injected into Gas Chromatograph model Shimadzu, Japan 17-A, fitted with a methyl lignoserate-coated (film thickness 0.25pm), SP-2330 (SUPELCO Inc. Supelco Park Bellefonte, PA 16823-0048, USA) polar capillary column (30 m x 0.32 mm) and a flame ionization detector. Fatty acids were identified and quantified by the FAME-37 internal standards (Sigma Aldrich, UK). Fat, protein, ash, lactose content, total solids, pH and acidity were determined by following the recommended methods of AOAC (2000). The viscosity readings were taken after ageing the mix at 4[degrees]C for 24 h. For the determination of melting time, ice creams were taken out from the storage compartment (-18[degrees]C), exposed to 20[degrees]C, the time required to fall the first drip was recorded as melting time and determined by the method of Abdou et al. (1996). Overrun of ice cream was also determined by the method prescribed by Abdou et al. (1996). Peroxide and anisidine values were determined as per methods of AOCS (1995). The ice creams were tempered to -18[degrees]C for 2 h before serving. Evaluation was performed by 10trainedjudges on a 9-point scale (1 was the worst and 9 the best) as prescribed by Larmond (1987). The statistical analysis of the triplicate experiments was performed by one way and two way analysis of variance techniques as prescribed by Steel et al. (1997) in a completely randomized design, the significant difference among the treatments was made by using Duncan's Multiple Range Test.

Results and Discussion

Characterisation of M. oleifera oil. Preliminary characterisation of cold pressed M. oleifera oil revealed free fatty acids 0.19% (oleic acid), moisture content 0.22%, colour on Lovibond Tintometer scale Red 2.1 and Yellow 3.2, unsaponifiable matter 1.29%, peroxide value 0.22 (meq[O.sub.2]/kg), iodine value 69.4 and slip melting point 19.8[degrees]C. The free radical scavenging activity, flavonoid content and total antioxidant activity of M. oleifera oil was 74.19%, 35.14 mg/100 g and 37.68%, respectively. Fatty acid profile of M. oleifera oil revealed that concentraction of C16:0, C18:0, C18:1 and C18:2 were 6.55%, 2.72%, 76.04% and 3.16%, respectivey.

Fatty acid profile. Fatty acid composition of milk fat, M. oleifera oil and their blends has been presented in Table 1. Marked changes were recorded in fatty acid composition of the blends after the formulation of blends particularly the content of short chain fatty acids declined from 10.65% (To) to 8.67, 7.49 and 6.68% in [T.sub.1], [T.sub.2] and [T.sub.3], respectively, which was 19.6,29.68 and 37.28% less than the control. Oleic acid increased from 26.55% (To) to 31.69, 36.94 and 42.15% in [T.sub.1], [T.sub.2] and [T.sub.3], respectively. Oleic acid progressively increased as a function of higher levels of M. oleifera oil. Lim et al. (2010) studied the effect of partial replacement of milk fat with flaxseed oil and observed progressive increase in the content of unsaturated fatty acids with increasing increments of flaxseed oil. Nadeem et al. (2010) incorporated rape seed oil into ice cream and recorded higher concentration of oleic acid in the blends, supplemented sunflower oil by M. oleifera oil and observed major difference in fatty acid composition of the blends. Mohammed et al. (2003) characterized M. oleifera oil with the objective to explore its potential as future's oil and reported that major fatty acid was oleic acid (78.9%). Fatty acid composition of M. oleifera oil was almost similar to olive oil. Mariod et al. (2005) studied the effect of blending on fatty acid composition of sunflower and Sclerocarya birrea oil. Oleic acid increased by 41.3% and linoleic acid decreased by 51% in the blend when blended in 60:40 ratios. Sunflower, palm oil and ground nut oils were blended in various proportions; fatty acid composition of blends was significantly distinguishable from the substrate oils.

Composition. The results of chemical composition of functional ice cream containing interesterified M. oleifera oil is given in Table 2. The addition of M. oleifera oil at all three levels did not show any effect on pH, acidity, fat, protein, ash content and total solids of ice cream. The reason could be the identical formulation and non-variation in the ingredients. Chemical composition of ice cream formulated from milk fat, palm kernel oil, cotton seed oil, dalda vanaspati, ground nut and rape seed oil was not different from the standard ice cream (Nadeem et al., 2010; Abdou et al., 1996; Adhikari and Arora, 1994; Miglani et al., 1987).

Viscosity. Viscosity of ice cream mix has a direct connection with the whipping process; higher viscosities are associated with better whipping ability (Lim et al., 2010). Viscosity of ice cream mixes supplemented with interesterified M. oleifera oil was not different from the control (Table 3). Partial replacement of milk fat with vegetable oils had a pronounced effect on the viscosity of ice cream mix (Im and Marshall, 1998; Adhikari and Arora, 1994). The results of the present study are different from the previously conducted research works, although vegetable oil was used yet it was chemically modified with different physical characteristics which definitely contributed in the improvement of the physical characteristics of ice cream.

Overrun. 30% replacement of milk with interesterified M. oleifera oil did not reveal any effect on overrun of ice cream (Table 3) however, significant changes were observed beyond this level. Replacement of milk fat with corn and rape seed oils decreased the overrun in mellorine (Nadeem et al., 2010). The results of this investigation are in partial confrontation of other researchers. These results can be justified by two; replacement level was not too high and secondly the fat used in this investigation was chemically modified having higher solid fat index and higher melting point.

Melting time. Melting time of all the experimental samples were at par with the control (Table 3). Other studies on milk fat replacement with vegetable oils revealed that, melting time markedly decreased as the milk fat was replaced with liquid vegetable oils. The results of this investigation were different from the literature due to the usage of interesterified M. oleifera oil which had greater melting point (35.6[degrees]C) than milk fat (34.6[degrees]C) and higher melting point improved the melting resistance (Adhikari and Arora, 1994) while, studying the replacement of butter fat with unmodified ground nut oil observed that replacement of milk fat significantly decreased the melting time (P<0.05). Melting time of the ice cream is directly dependent on the melting point of fats as the fats with lower melting point will melt quickly (Flack, 1988). For ice cream the fats having melting point in the range of34-36[degrees]C may give the optimum melting time. The fat used in this study was wisely interesterified to increase the melting point from 18 to 34.6[degrees]C which contributed in the melting resistance of ice cream and confer the melting time to be almost similar to milk fat at medium level of fat replacement ([T.sub.2]).

Changes in fatty acid composition. Determination of fatty acid composition of three months stored ice cream exhibited two different trends; saturated fatty acids increased whereas, unsaturated fatty acid decreased as a function of storage period (Table 4). The increase or decrease in the extents of saturated and unsaturated fatty acids could be attributed to the better oxidative stability of saturated fatty acids and break down of unsaturated fatty acids into the oxidation products. Supplementation of milk fat with M. oleifera oil at all three levels tended to inhibit the autoxidation process in the stored ice cream. The strong inhibition of the oxidative breakdown in the supplemented ice creams could be attributed to the presence of higher concentration of polyphenolic compounds in M. oleifera oil. The concentration of unsaturated fatty acids decreased in ice cream supplemented with flaxseed oil during the course of 42-days storage period (Lim el al, 2010). Long term storage of butter at refrigeration and freezing conditions increased the extents of oxidation products (Krause el al, 2008). In an another study related to the determination of oxidative stability of olein based ice creams it was observed the enhancement of saturated fatty acids and decline of unsaturated fatty acids during 6-months storage (Nadeem el al., 2013a).

Peroxide value: Supplementation of milk fat with interesterified M. oleifera oil at all concentrations considerably inhibited the formation of primary oxidation products (Table 5). Enhancement of unsaturated fatty acids in ice cream either by using modified milk fat or vegetable oils results in development of oxidized flavour in ice cream during the storage process (Lim el al., 2010; Gonzalez el al., 2003). In this study, the use of M. oleifera oil offered a unique benefit of enhancing the beneficial oleic acid without posing a problem of rancid flavour. The lower extents of primary oxidation products could be attributed to the lower oxidation susceptibility of oleic acid and presence of phenolic compounds. Enhancement of the oxidative stability of soybean and sunflower oils by mixing with M. oleifera oil has been reported by strong inhibition of the autoxidation process was also observed when butter oil was blended with M. oleifera oil (Nadeem el al., 2013b). Flavour score and peroxide value were highly correlated and determination intervals showing higher peroxide value revealed lower flavour score (Fig. 1). Generation of oxidation products decreased the flavour score of olein based ice creams (Nadeem el al., 2013a).

Anisidine value. Anisidine value measures the magnitude of secondary oxidation products generated in fats and oils during the course of autoxidation, higher values usually anticipate poor storage stability (Pritchard, 1991). Ice creams supplemented with M. oleifera oil exhibited better storage stability over the control due to the strong inhibition of free radical mechanism thus leading to the formation of secondary oxidation products (Table 5). Enhancement of the unsaturated fatty acids in ice cream by the manipulation of the cow's ration with unsaturated fatty acids and flaxseed oil in ice cream rendered it vulnerable to the oxidative breakdown (Lim el al., 2010; Gonzalez el al., 2003). Olein based ice creams yielded the higher extents of secondary oxidation products during storage of 6-months (Nadeem et al., 2013a).

Free fatty acids. The free fatty acids of the control and all the treatments steadily increased during 3 months storage period and were at par with each other. Supplementation of ice cream with M. oleifera oil was ineffective to stop the generation of free fatty acids during the storage period (Table 5). Free fatty acids in food systems are produced due to the hydrolytic activities of lipases, presence of moisture, metal ion contamination etc. and phenolic compounds do not have a mechanism to stop their formation. Free fatty acids are associated with the generation of off flavours in foods; higher values can have a negative influence on the quality of the stuffs (Fox and McSweeney, 2003). Free fatty acid content of three months stored ice creams were within the acceptable limits. Free fatty acids of six months stored olein based ice creams and control were not different from each other (Nadeem et al., 2013a).

Sensory evaluation. The results of sensory evaluation of fresh ice cream depicted that the addition of interesterified M. oleifera oil at 20% level did not impart any effect on colour score (Table 6). Milk fat is unique among the edible fats for having appreciable amount of short chain fatty acids which are responsible for characteristics flavour of milk and milk products (Marshall et al., 2003). Replacement of milk fat up to 20% level created non distinguishable difference in flavour of ice cream. As the replacement level increased to 30% flavour score decreased from 7.1 (T0) to 6.5 ([T.sub.3]). The decline in flavour score could be attributed to the lower concentration of short chain fatty acids in [T.sub.3]. The texture score of the control and [T.sub.3] were at par with each other (P>0.05). The results of the present investigation are not in line with the findings of Nadeem et al. (2010) who reported lower texture score when milk fat was replaced with rape seed oil. The deviation in texture score was due to the difference in the type of edible oil. Interesterified M. oleifera oil was used which had higher melting point than the milk fat, which definitely contributed in the texture of the ice creams.

[FIGURE 1 OMITTED]

Conclusion

Addition of interesterified M.oleifera oil did not have any effect on compositional attributes, overrun, viscosity and melting time, rather it improved the texture and storage stability of ice cream.

Means of triplicate experiment and means sharing same letter in a column are non significant, refer Table 1 for the detail of treatments.

References

Abdou, S.M., Montasser, E.A., Younis, H.A. 1996. Evaluation of some dairy blends for dietetic ice cream. Egyptian Journal of Dairy Science, 24: 103-114.

Adhikari, K., Arora, K.A. 1994. Development of mellorine type frozen desserts: effect of stabilizers and emulsifiers. Indian Journal of Animal Sciences, 64: 526-533.

AOAC, 2000. Official Methods of Analysis. American Association of Anaytical Chemists. Inc., 17th edition, Washington, D.C., USA.

AOAC, 1997. Official Methods of Analysis, 16th edition, Association of Official Analytical Chemists, AOAC International Gaithersburg, MD, USA.

AOCS, 1995. Official Methods and Recommended Practices of the American Oil Chemists ' Society, 4th edition, AOCS, Champaign, IL, USA.

Flack, E. 1988. Factors which influence the melting properties of ice cream. Ice cream and Frozen Confectionary, 39: 232-235.

Fox, P.F., McSweeney, P.L.H. 2003. Advanced Dairy Chemistry, Proteins. vol. 1, 3rd edition, Kluwer Academic/Plenum Publishers, N.Y., USA.

Gonzalez, S., Duncan, S.E., Keefe, S.F., Sumner, S.S., Herbein, J.H. 2003. Oxidation and textural characteristics of butter and ice cream with modified fatty acid profiles. Journal of Dairy Science, 86: 70-77.

Hansel, B., Nicolle, C., Lalanne, F., Tondu, F., Lassel, T., Donazzolo, Y., Ferrieres, J., Krempf, M., Schlienger, J. L., Verges, B., Chapman, M.J., Bracket, E. 2007. Effect of low-fat, fermented milk enriched with plant sterols on serum lipid profile and oxidative stress in moderate hypercholesterolemia. The American Journal of Clinical Nutrition, 86: 790-796.

Honda, S., Tanaka, K., Hamada, K., Kitagawa, H., Kishida, H. 2007. Lipid Absorption Inhibitor for Preventing Cardiovascular Disorders, e.g. Hyperlipidemia or Hypertriglyceridemia, Contains (gamma)-Cyclodextrin as Active Ingredient. Patent number (s):JP2007284366-A.

Im, Ji-S., Marshall, R. 1998. Effects of homogenization pressure on the physical, chemical and sensory properties of formulated frozen. Food Science and Biotechnology, 7: 90-94.

Krause, A.J., Miracle, R.E., Sanders, T.H., Dean, L.L., Drake, M.A. 2008. The effect of refrigerated and frozen storage on butter flavor and texture. Journal ofDairyScience, 91: 455-465.

Larmond, E. 1987. Laboratory Methods for Sensory Evaluation of Food. pp. 35-37,1st edition, Reasearch Branch, Canada, Department of Agriculture, Ottawa Publications, Canada.

Lim, C.W., Norziah, M.H., Lu, H.F.S. 2010. Effect of flaxseed oil towards physicochemical and sensory characteristic of reduced fat ice-creams and its stability in ice-creams upon storage. International FoodResearchJournal, 17: 393-403.

Mariod, A., Matthaus, B., Eichner, K., Hussein, I.H. 2005. Improving the oxidative stability of sun flower oil by blending with Sclerocarya birrea oil and Aspongopus viduatus oils. Journal of Food Lipids, 12: 150-158.

Marshall, R.T., Goff, H.D., Hartel, R.W. 2003. Ice cream, pp. 123-125, 6th edition. Kluwer Academic/ Plenum Publishes, New York, USA.

Miglani, N., Jain, S.C., Shukla, P.C. 1987. Studies on the technology of partially filled ice cream using buffalo milk and vegetable oils. Beverage and Food World, 14: 19-25.

Mohammed, A.S., Lai, O.M., Muhammad, S.K.S., Long, K., Ghazali, H.M. 2003. Moringa oleifera, potentially a new source of oleic acid-type oil for Malaysia. In: Investing in Innovation. Bioscience and Biotechnology, AM Hassan (ed.) pp. 137-140, Selangor; Universiti Putra Malaysian Press, Serolang, Malaysia.

Nadeem, M., Abdullah, M., Khalique, A., Hussain, I., Mahmud, A., Inayat. S. 2013a. The effect of Moringa oleifera leaf extract as antioxidant on stabilization of butter oil with modified fatty acid profile. Journal of Agriculture Science and Technology, 15: 919-928.

Nadeem, M., Abdullha, M., Hussain, I., Inayat, S., Javid, A., Zahoor, Y. 2013b. Antioxidant potential of Moringa oleifera leaf extract for the stabilisation of butter at refrigeration temperature. Czech Journal of Food Science, 3: 332-339.

Nadeem, M., Abdullah, M., Javid, A., Arif, A.M., Mahmood, T. 2012. Evaluation of functional fat from interesterified blends of butter oil and Moringa oleifera oil. Pakistan Journal of Nutrition, 11 : 725-729.

Nadeem, M., Abdullah, M., Ellahi, M.Y. 2010. Effect of incorporating rape seed oil on quality of ice cream. Mediterranean Journal of Nutrition and Metabolism, 3: 121-126.

Osman, A., Nor, A.I. 1999. Physical and chemical properties of shortenings from palm oil: tallow and palm olein: tallow blends with and without interesterification. Journal of Oil Palm Research, 11: 1-10.

Pritchard, J.L.R. 1991. Analysis and Properties of Oilseeds. In: Analysis of Oilseeds, Fats and Fatty Foods, J. B. Rossell and J.L.R. Pritchared (eds.), pp. 80,89,127, Elsevier Applied Sciences, New York, USA.

Qian, M. 2003. Gas Chromatography. In: Food Analysis Laboratory Manual, pp. 129-133, 3rd edition, Kluwer Academic Publishers, New York, USA.

Sreenivasan, B. 1978. Interesterification of fats. Journal of American Oil Chemists' Society, 55: 796-805.

Steel, R.G.D., Torrie, J.H., Dickey, D.A. 1997. Principles and Procedures of Statistics. A Biometrical Approach, pp. 97-102, 3rd edition, Mc-Graw Hill Book Co. New York, USA.

Tsakinis, J., Lalas, S., Gergis, V., Dourtoglou, V., Spiliotis, V. 1998. A total characterization of Moringa oleifera Malawi seed oil. La Rivista Italianasostanza Grasse, 75: 21-27.

Williams, C.M. 2000. Dietary fatty acids and human health. AnnalesdeZootechnie, 49: 165-180.

Muhammad Nadeem *, Rahman Ullah and Ansar Ullah

Department of Dairy Technology, University of Veterinary and Animal Sciences, Lahore, Pakistan

(received December 1, 2014; revised August 19, 2015; accepted September 3, 2015)

* Author for correspondence; E-mail: sheikhnadeem@live.com
Table 1. Fatty acid composition of various treatments of ice
cream containing interesterified Moringa oleifera oil, milk
fat and their blends

Fatty acid   [T.sub.0]                 [T.sub.1]

C4:0         4.47 [+ or -] 0.09 (d)    4.10 [+ or -] 0.03 (b)
C6:0         2.28 [+ or -] 0.12 (a)    2.04 [+ or -] 0.05 (b)
C8:0         1.34 [+ or -] 0.04 (a)    1.21 [+ or -] 0.01 (a)
C10:0        2.56 [+ or -] 0.07 (a)    2.32 [+ or -] 0.04 (b)
C12:0        2.66 [+ or -] 0.15 (a)    2.36 [+ or -] 0.06 (b)
C14:0        9.24 [+ or -] 0.19 (a)    8.35 [+ or -] 0.09 (b)
C16:0        25.84 [+ or -] 0.23 (a)   23.95 [+ or -] 0.12 (b)
C18:0        14.65 [+ or -] 0.11 (a)   13.45 [+ or -] 0.02 (b)
C18:1        26.55 [+ or -] 0.16 (d)   31.69 [+ or -] 0.14 (c)
C18:2        1.93 [+ or -] 0.12 (d)    2.14 [+ or -] 0.17 (c)
C18:3        1.31 [+ or -] 0.05 (a)    1.17 [+ or -] 0.05 (b)
C20:0        0.15 [+ or -] 0.02 (d)    0.37 [+ or -] 0.01 (c)

Fatty acid   [T.sub.2]                 [T.sub.3]

C4:0         3.57 [+ or -] 0.11 (c)    3.12 [+ or -] 0.01 (c)
C6:0         1.84 [+ or -] 0.02 (c)    1.56 [+ or -] 0.04 (d)
C8:0         1.06 [+ or -] 0.01 (b)    0.95 [+ or -] 0.07 (b)
C10:0        1.85 [+ or -] 0.07 (c)    1.75 [+ or -] 0.11 (d)
C12:0        2.14 [+ or -] 0.02 (c)    1.84 [+ or -] 0.04 (d)
C14:0        7.44 [+ or -] 0.05 (c)    6.46 [+ or -] 0.15 (d)
C16:0        22.05 [+ or -] 0.18 (c)   18.15 [+ or -] 0.10 (d)
C18:0        12.34 [+ or -] 0.07 (c)   11.14 [+ or -] 0.06 (d)
C18:1        36.94 [+ or -] 0.23 (b)   42.15 [+ or -] 0.12 (a)
C18:2        2.34 [+ or -] 0.09 (b)    2.58 [+ or -] 0.22 (a)
C18:3        1.03 [+ or -] 0.03 (c)    0.82 [+ or -] 0.09 (d)
C20:0        0.61 [+ or -] 0.05 (b)    0.87 [+ or -] 0.02 (a)

Table 2. Effect of replacing milk fat with interesterified
M.oleifera oil on composition of ice cream

Treatments   Fat%                 Protein%

[T.sub.0]    9.84 [+ or -] 0.06   4.05 [+ or -] 0.47
[T.sub.1]    9.85 [+ or -] 0.09   4.01 [+ or -] 0.42
[T.sub.2]    9.94 [+ or -] 0.16   3.95 [+ or -] 0.21
[T.sub.3]    9.78 [+ or -] 0.11   3.81 [+ or -] 0.56

Treatments   Ash%                 Total solids%

[T.sub.0]    0.73 [+ or -] 0.17   36.18 [+ or -] 0.10
[T.sub.1]    0.70 [+ or -] 0.17   36.15 [+ or -] 0.10
[T.sub.2]    0.72 [+ or -] 0.09   36.09 [+ or -] 0.10
[T.sub.3]    0.71 [+ or -] 0.09   36.03 [+ or -] 0.05

Treatments   pH                   Acidity%

[T.sub.0]    6.70 [+ or -] 0.05   0.17 [+ or -] 0.04
[T.sub.1]    6.68 [+ or -] 0.03   0.18 [+ or -] 0.01
[T.sub.2]    6.71 [+ or -] 0.01   0.16 [+ or -] 0.03
[T.sub.3]    6.75 [+ or -] 0.05   0.16 [+ or -] 0.08

Refer to Table 1 for the detail of treatment.

Table 3. Effect of replacing milk fat with interesterified
M. oleifera oil on physical characteristics of ice cream

Treatments   Viscosity (CP)        Overrun (%)

[T.sub.0]    67.38 [+ or -] 1.55   82.2 [+ or -] 1.23
[T.sub.1]    65.98 [+ or -] 1.47   81.9 [+ or -] 1.45
[T.sub.2]    64.29 [+ or -] 1.34   70.3 [+ or -] 1.99
[T.sub.3]    63.18 [+ or -] 1.32   77.5 [+ or -] 1.79

Treatments   Melting time (min)   MP ([degrees]C)

[T.sub.0]    6.33 [+ or -] 0.90   34.8 [+ or -] 0.2
[T.sub.1]    6.15 [+ or -] 1.71   34.6 [+ or -] 0.1
[T.sub.2]    5.98 [+ or -] 0.95   35.0 [+ or -] 0.3
[T.sub.3]    5.70 [+ or -] 1.10   35.2 [+ or -] 0.2

Table 4. Changes in major fatty acids of fresh and
3 months stored ice cream

Fatty acids   [T.sub.0]-Fresh        [T.sub.0]-3M

C16:0         25.84 [+ or -] 0.23b   27.42 [+ or -] 0.82a
C18:0         14.65 [+ or -] 0.11b   15.89 [+ or -] 0.73a
C18:1         26.55 [+ or -] 0.16b   24.15 [+ or -] 0.44c
C18:2         1.93 [+ or -] 0.12b    1.24 [+ or -] 0.11c

Fatty acids   [T.sub.1]-3M           [T.sub.2]-3M

C16:0         25.36 [+ or -] 1.16b   25.51 [+ or -] 0.92b
C18:0         15.12 [+ or -] 0.38b   15.79 [+ or -] 0.61b
C18:1         25.94 [+ or -] 0.75b   26.17 [+ or -] 0.97b
C18:2         1.65 [+ or -] 0.08b    1.74 [+ or -] 0.16b

Fatty acids   [T.sub.3]-3M

C16:0         25.72 [+ or -] 0.54b
C18:0         15.93 [+ or -] 0.71b
C18:1         26.39 [+ or -] 0.58b
C18:2         1.79 [+ or -] 0.07b

3M = three months stored ice cream at -18[degrees]C;
means with different letter in a row are not
different; refer Table 1 for the detail of
treatments.

Table 5. Effect of interesterified M.oleifera oil
on storage stability of ice cream

Treatment              Peroxide value

            Fresh                 3M

[T.sub.0]   0.25 [+ or -] 0.03a   1.12 [+ or -] 0.08a
[T.sub.1]   0.28 [+ or -] 0.02a   0.72 [+ or -] 0.06b
[T.sub.2]   0.26 [+ or -] 0.03a   0.54 [+ or -] 0.05c
[T.sub.3]   0.21 [+ or -] 0.01a   0.39 [+ or -] 0.02d

Treatment             Anisidine value

            Fresh                 3M

[T.sub.0]   3.58 [+ or -] 0.12a   13.59 [+ or -] 0.43a
[T.sub.1]   3.62 [+ or -] 0.18a   9.72 [+ or -] 0.24b
[T.sub.2]   3.68 [+ or -] 0.07a   6.65 [+ or -] 0.30c
[T.sub.3]   3.52 [+ or -] 0.04a   5.18 [+ or -] 0.22d

Treatment               FFA (%)

            Fresh                 3M

[T.sub.0]   0.11 [+ or -] 0.1a    0.16 [+ or -] 0.02a
[T.sub.1]   0.10 [+ or -] 0.01a   0.16 [+ or -] 0.02a
[T.sub.2]   0.11 [+ or -] 0.01a   0.15 [+ or -] 0.01a
[T.sub.3]   0.11 [+ or -] 0.02a   0.16 [+ or -] 0.01a

Means denoted by different letter in a column are
different, 3M = three months stored ice cream at
-18[degrees]C, Peroxide value (Meq[O.sub.2]/kg);
FFA = free fatty acids.

Table 6. Effect of replacing milk fat with
interesterified M. oleifera oil on sensory
characteristics of fresh ice cream

Treatment   Colour               Flavour

[T.sub.0]   7.4 [+ or -] 0.25a   7.1 [+ or -] 0.41a
[T.sub.1]   7.2 [+ or -] 0.31a   7.0 [+ or -] 0.05a
[T.sub.2]   7.2 [+ or -] 0.45a   6.9 [+ or -] 0.43a
[T.sub.3]   6.9 [+ or -] 0.34a   6.5 [+ or -] 0.17b

Treatment   Texture              Overall
                                 acceptability

[T.sub.0]   7.7 [+ or -] 0.15a   7.4 [+ or -] 0.24a
[T.sub.1]   7.6 [+ or -] 0.19a   7.2 [+ or -] 0.08a
[T.sub.2]   7.4 [+ or -] 0.24a   7.2 [+ or -] 0.31a
[T.sub.3]   7.5 [+ or -] 0.14a   6.7 [+ or -] 0.28b

Means of triplicate experiment and means sharing
same letter in a column are non significant,
refer Table 1 for the detail of treatments.
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Author:Nadeem, Muhammad; Ullah, Rahman; Ullah, Ansar
Publication:Pakistan Journal of Scientific and Industrial Research Series B: Biological Sciences
Article Type:Report
Date:Mar 1, 2016
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