acid value and slip melting point o

acid value and slip melting point of MSF, were reported in our previous study (Jahurul, Zaidul, Nik Norulaini, Sahena, & Mohd Omar,
2013b). In the present study, the triglyceride compositions, thermal properties, solid fat content, and crystal morphology of MSF
and PS blends are investigated.
2. Materials and methods
2.1. Materials
Mango seed fat (MSF) was extracted from the Malaysian waterlily mango variety using SC–CO2, and their fatty acid constituents
have been described byJahurul et al. (2013b). This MSF was used
as the blending component in this analysis. Palm stearin (PS) was
obtained from Sime Darby Research Sdn. Bhd., Malaysia. Standards
of triglycerides, acetone and acetonitrile (HPLC grade) were purchased from Sigma, Merck, and Fisher (Malaysia).
2.2. Blending of MSF and PS
In order to assess the suitability of the blends containing MSF
and PS as CBRs, a total of ten blends of these fats, in 5% increments
of PS, were prepared: MSF/PS, 95:5 (blend 1), 90:10 (blend 2),
85:15 (blend 3), 80:20 (blend 4), 75:25 (blend 5), 70:30 (blend
6), 65:35 (blend 7), 60:40 (blend 8), 55:45 (blend 9), and 50:50
(blend 10). The TG compositions, crystallization and melting properties, SFC and morphology of these blends were analysed and discussed below.
2.3. Determination of triglycerides (TGs)
A high performance liquid chromatography (HPLC) method,
established by the American Oil Chemists’ Society (AOCS., 2003),
was used to determine the triglyceride compositions of all blends.
A 10% each blend solution was prepared using acetone as the solvent. The solution was then filtered through a TE 36 membrane filter (PTFE; 0.45lm) (Millipore) before being injected into the HPLC.
The triglyceride content was determined using Agilent HPLC
instrument (Agilent HPLC Series 1200, Degasser Model G1322A,
Quaternary Pump Model G1311A, RI Detector Model G1362A),
and a Lichrospher 100 RP-18e HPLC column (4 mm i.d.250 mm
length) with a column temperature of 30–35C, column pressure
of 5–6 MPa, mobile phase (acetone/acetonitrile 70:30 v/v), a
mobile phase flow rate of 1 ml/min and an injection volume of
10ll. The percentage of triglycerides was determined by calculating the peak area of the chromatogram. Analyses were conducted
in triplicates.
2.4. Determination of solid fat content (SFC) by pNMR
The SFC of the fat blends, as a function of temperature, was
determined by pulsed nuclear magnetic resonance (pNMR) (Bruker
minispec mq20 NMR analyser), following the method developed
byFiebig and Lüttke (2003). Each blend was tempered at 80 C
for 30 min, followed by chilling at 0C for 90 min and kept at the
desired temperatures for 30 min prior to measurements. The preequilibrated thermostat bath was used to carry out the melting,
chilling and holding of the test samples. The temperature ranges
used for the determination of SFC were 10–80C. All analyses were
conducted in triplicate.
2.5. Analysis of crystallization and melting characteristics by DSC
Differential scanning calorimetry (DSC Q200, TA Instrument)
was used to monitor the melting and crystallization behaviour of
the blends of MSF and PS. The DSC instrument was calibrated using
indium. All the blends of MSF and PS were melted at 80C. Approximately 3–5 mg of the molten samples were transferred to standard DSC aluminium pans using a micropipette and then
hermetically sealed. The pans were then placed in vials and melted
at 80C for 30 min. For stabilization, the pans were placed in an
incubator at 26C for 7 days. After 7 days of incubation at 26C,
the pans were transferred to the DSC head. An empty hermetically
sealed DSC aluminium pan was used as a reference. For the DSC
experiments the following programme was used: cooling to
60C and melting the samples at a rate of 30C/min to 80C
for 20 min to insure a completely liquid state, cooling at 10C/
min to60C, holding at60C for 2 min, heating at 10C/min
to 80C. During melting and cooling, the enthalpy change of fat
blends was measured. All analyses were carried out in triplicates.
2.6. Crystal morphological study by polarised light microscopy (PLM)
Polarised light microscopy (Nicon, ECLIPSE E200, Tokyo, Japan),
equipped with digital camera, was used to monitor the microstructure of the crystal network of the blends of MSF and PS. The method developed byNarine and Marangoni (1999)was used for the
crystallization of fat blends. In order to destroy any crystal memory, all the fat blends were melted at 80C for 30 min. About
15ll of melted fat blend was placed on the microscopic slide,
which was heated at the same temperature. Then, a coverslip preheated to the same temperature was carefully placed on the top of
the fat sample to observe the structure. The slides were transferred
to a refrigerator for chilling at 4C (1 h), then stored in a temperature-controlled cabinet at 21–23C for 48 h for proper crystallization. All analyses were carried out in triplicates.
2.7. Statistical analysis
Analyses were carried out in triplicates in this study. Analysis of
variance (ANOVA) was used to test the differences between different triglycerides in different blends. Ap< 0.05 was considered to
be statistically significant. The Minitab software (version 16) was
used to perform the analysis.
3. Results and discussion
3.1. Triglyceride compositions
Fig. 1shows the TG compositions of the MSF and PS blends
(1–10 blends). TGs are the major constituents of fats and oils.
The complex mixtures of TGs of the blends of MSF and PS constituted from different type of fatty acids. Therefore, variations
in TG compositions were observed amongst blends. As shown in
Fig. 1, all the blends had three main TGs; namely, 1,3-dipalmitoyl-2-oleoylglycerol (POP), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS), and 1,3-distearoyl-2-oleoyl-glycerol (SOS). The TG
profiles in the MSF and PS blends were significantly affected by
the blending ratios. The amounts of each TG were also significantly
different (p< 0.05) amongst the blends.
SOS was identified as the major TG component, comprising of
31.4–37.2% of the total triglycerides, followed by POP and POS
with 8.6–17.7% and 12.5–19.6%, respectively. The high content of
SOS is responsible for thebformation of the crystal, while POP
and POS forb
0
formation of crystals (Toro-Vazquez, Pérez-Martínez,
Dibildox-Alvarado, Charó-Alonso, & Reyes- Hernández, 2004). The
results also show that POP and POS were the major TGs found in
increasing order, whereas SOS in decreasing order with the addition of PS. For example, the percentage of POP and POS increased
from 8.6% to 11.6% and from 12.5% to 14.8% with an increase in

Hasil (Bahasa Indonesia) 1:

acid value and slip melting point of MSF, were reported in our previous study (Jahurul, Zaidul, Nik Norulaini, Sahena, & Mohd Omar,2013b). In the present study, the triglyceride compositions, thermal properties, solid fat content, and crystal morphology of MSFand PS blends are investigated.2. Materials and methods2.1. MaterialsMango seed fat (MSF) was extracted from the Malaysian waterlily mango variety using SC–CO2, and their fatty acid constituentshave been described byJahurul et al. (2013b). This MSF was usedas the blending component in this analysis. Palm stearin (PS) wasobtained from Sime Darby Research Sdn. Bhd., Malaysia. Standardsof triglycerides, acetone and acetonitrile (HPLC grade) were purchased from Sigma, Merck, and Fisher (Malaysia).2.2. Blending of MSF and PSIn order to assess the suitability of the blends containing MSFand PS as CBRs, a total of ten blends of these fats, in 5% incrementsof PS, were prepared: MSF/PS, 95:5 (blend 1), 90:10 (blend 2),85:15 (blend 3), 80:20 (blend 4), 75:25 (blend 5), 70:30 (blend6), 65:35 (blend 7), 60:40 (blend 8), 55:45 (blend 9), and 50:50(blend 10). The TG compositions, crystallization and melting properties, SFC and morphology of these blends were analysed and discussed below.2.3. Determination of triglycerides (TGs)A high performance liquid chromatography (HPLC) method,established by the American Oil Chemists’ Society (AOCS., 2003),was used to determine the triglyceride compositions of all blends.A 10% each blend solution was prepared using acetone as the solvent. The solution was then filtered through a TE 36 membrane filter (PTFE; 0.45lm) (Millipore) before being injected into the HPLC.The triglyceride content was determined using Agilent HPLCinstrument (Agilent HPLC Series 1200, Degasser Model G1322A,Quaternary Pump Model G1311A, RI Detector Model G1362A),and a Lichrospher 100 RP-18e HPLC column (4 mm i.d.250 mmlength) with a column temperature of 30–35C, column pressureof 5–6 MPa, mobile phase (acetone/acetonitrile 70:30 v/v), amobile phase flow rate of 1 ml/min and an injection volume of10ll. The percentage of triglycerides was determined by calculating the peak area of the chromatogram. Analyses were conductedin triplicates.2.4. Determination of solid fat content (SFC) by pNMRThe SFC of the fat blends, as a function of temperature, wasdetermined by pulsed nuclear magnetic resonance (pNMR) (Brukerminispec mq20 NMR analyser), following the method developedbyFiebig and Lüttke (2003). Each blend was tempered at 80 Cfor 30 min, followed by chilling at 0C for 90 min and kept at thedesired temperatures for 30 min prior to measurements. The preequilibrated thermostat bath was used to carry out the melting,chilling and holding of the test samples. The temperature rangesused for the determination of SFC were 10–80C. All analyses weredilakukan dalam rangkap tiga.2.5. analisis kristalisasi dan mencair karakteristik oleh DSCDiferensial pemindaian kalorimetri (DSC Q200, TA instrumen)digunakan untuk memantau mencair dan kristalisasi perilakucampuran MSF dan PS. DSC instrumen dikalibrasi dengan menggunakanindium. Semua campuran MSF dan PS dicairkan di 80 C. sekitar 3-5 mg dari cair sampel dipindahkan ke standar DSC aluminium panci menggunakan micropipette dan kemudiantertutup rapat. Panci kemudian ditempatkan dalam cawan dan melelehat 80 C selama 30 menit. Untuk stabilisasi, panci ditempatkan diInkubator 26 c selama 7 hari. Setelah 7 hari inkubasi pada 26 C,panci dipindahkan ke kepala DSC. Kosong hermeticallydisegel DSC aluminium panci digunakan sebagai referensi. Untuk DSCpercobaan program berikut digunakan: cooling untuk60 C dan mencair sampel pada tingkat 30 C/menit sampai 80 Cuntuk 20 menit untuk memastikan keadaan sepenuhnya cair, pendinginan pada 10 C /min c 60, memegang di 60 C selama 2 menit, Penghangat Ruangan di 10 C/minc. 80 Selama pelelehan dan pendinginan, Perubahan entalpi lemakcampuran diukur. Semua analisis dilakukan di triplicates.2.6. kristal morfologi studi oleh terpolarisasi light Microscope (PLM)Terpolarisasi light Microscope (Nicon, ECLIPSE E200, Tokyo, Jepang),dilengkapi dengan kamera digital, digunakan untuk memantau mikrostruktur jaringan kristal campuran MSF dan PS. Metode yang dikembangkan byNarine dan Marangoni (1999) digunakan untukkristalisasi dari campuran lemak. Untuk menghancurkan setiap ingatan kristal, campuran semua lemak dicairkan di 80 C selama 30 menit kemudian cycling tentang15ll campuran lemak meleleh ditempatkan pada slide mikroskopis,yang dipanaskan pada suhu yang sama. Kemudian, coverslip dipanaskan ke suhu sama dengan hati-hati diletakkan atassampel lemak untuk mengamati struktur. Slide dipindahkanuntuk lemari es untuk dingin di 4 C (1 h), kemudian disimpan dalam lemari pengontrol suhu pada 21 – 23 C untuk 48 jam untuk kristalisasi yang tepat. Semua analisis dilakukan di triplicates.2.7. analisis statistikAnalisis dilakukan di triplicates dalam studi ini. Analisisvarians (ANOVA) digunakan untuk menguji perbedaan antara triglycerides yang berlainan dalam campuran yang berbeda. AP < 0,05 dianggapmenjadi signifikan secara statistik. Perangkat lunak Minitab (versi 16)digunakan untuk melakukan analisis.3. hasil dan diskusi3.1. trigliserida komposisiGbr 1shows komposisi TG MSF dan PS campuran(campuran 1-10). TGs adalah konstituen utama dari lemak dan minyak.Campuran kompleks TGs campuran MSF dan PS dari berbeda jenis asam lemak. Oleh karena itu, variasidi TG komposisi diamati antara campuran. Seperti yang ditunjukkan dalamGambar 1, Semua campuran telah tiga TGs utama; yaitu, 1,3-dipalmitoyl-2-oleoylglycerol (POP), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS), dan 1,3-distearoyl-2-oleoyl-gliserol (SOS). TGProfil di MSF dan PS campuran secara signifikan dipengaruhi olehrasio pencampuran. Jumlah TG setiap secara juga signifikanberbeda (p < 0.05) antara campuran.SOS diidentifikasikan sebagai komponen TG utama, yang terdiri dari31,4 – 37,2% dari total trigliserida, diikuti oleh POP dan POS8.6 – 17.7% dengan 12,5-19,6%, masing-masing. Tingginya kandunganSOS bertanggung jawab untuk thebformation Crystal, sementara POPdan POS forb0pembentukan kristal (Toro-Vazquez, Pérez-Martínez,Dibildox-Alvarado, Charó-Alonso, & Reyes - Hernández, 2004). Thehasil juga menunjukkan bahwa POP dan POS TGs utama yang ditemukan dimeningkatkan perintah, sedangkan SOS penurunan memesan dengan penambahan PS. Sebagai contoh, persentase POP dan POS meningkatdari 8,6% dari 12.5% untuk 14,8% dengan peningkatan dan 11.6%