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Fulltext Physicochemical properties of rambutan (Nephelium lappaceum L.) seed during natural fermentation of the whole peeled fruit

Chai, K. F., Adzahan, N. M., Karim, R., Rukayadi, Y., Ghazali, H. M.

International Food Research Journal, 2020;27(3):397-407.
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A novel way to reduce rambutan wastage is to ferment the fruit and valorise the seed post-fer- mentation into other food products and ingredients. Hence, the objective of this study was to investigate the physicochemical properties of rambutan seed during solid-state fermentation of the fruit. Peeled rambutan fruits were subjected to natural fermentation for ten days at 30°C. The environmental temperature, relative humidity, internal and external temperatures of the fermentation mass were measured daily. After ten days of fermentation, the seeds had higher cut test score (867.5), fermentation index (1.527), and a* value (8.20 for non-dried seeds and
9.93 for dried seeds), and lower L* (51.90 for non-dried seeds and 49.22 for dried seeds) and b* (30.52 for non-dried seeds and 30.12 for dried seeds) values; as compared to the non-fer- mented seeds (cut test score, 0.0; fermentation index, 0.856; L*, a*, and b* values, 64.52, 2.25, and 42.07 for non-dried seeds, respectively, and 61.03, 3.23 and 36.70 for dried seeds, respectively). During this time, pH, total soluble solids, fructose, glucose, sucrose, citric acid, and tartaric acid contents of the seeds decreased by 46, 44, 59, 61, 100, 85, and 100%, respec- tively, while the titratable acidity, lactic acid, acetic acid, and ascorbic acid contents of the seeds increased by 5.5, 7.8, 6.0, and 2.2-fold, respectively. Results showed that eight days of fermentation are adequate to produce well-fermented rambutan seeds that could be further processed into a cocoa powder-like product by roasting the fermented fruits in a manner similar to that of cocoa bean roasting.
Assessing the quality of sardine based on biogenic amines using a fuzzy logic model

Zare D, Ghazali HM

Food Chem, 2017 Apr 15;221:936-943.
PMID: 27979297 DOI: 10.1016/j.foodchem.2016.11.071

There is an increasing concern about the quality and quality assessment procedures of seafood. In the present study, a model to assess fish quality based on biogenic amine contents using fuzzy logic model (FLM) is proposed. The fish used was sardine (Sardinella sp.) where the production of eight biogenic amines was monitored over fifteen days of storage at 0, 3 and 10°C. Based on the results, histamine, putrescine and cadaverine were selected as input variables and twelve quality grades were considered for quality of fish as output variables for the FLM. Input data were processed by rules established in the model and were then defuzzified according to defined output variables. Finally, the quality of fish was evaluated using the designed model and Pearson correlation between storage times with quality of fish showed r=0.97, 0.95 and 1 for fish stored at 0, 3 and 10°C, respectively.
Trans- and cis-urocanic acid, biogenic amine and amino acid contents in ikan pekasam (fermented fish) produced from Javanese carp (Puntius gonionotus) and black tilapia (Oreochromis mossambicus)

Ezzat MA, Zare D, Karim R, Ghazali HM

Food Chem, 2015 Apr 1;172:893-9.
PMID: 25442635 DOI: 10.1016/j.foodchem.2014.09.158

Ikan pekasam is a fermented fish product produced in Malaysia and is usually made from freshwater fish with ground roasted uncooked rice as the main source of carbohydrate. In this study, the amino acid, biogenic amine, and trans- and cis-urocanic acid (UCA) contents of fifteen commercial samples of Ikan pekasam made from Javanese carp and black tilapia, that had undergone either natural or acid-assisted fermentation, were quantified. The latter includes either tamarind (Tamarindus indica) pulp or dried slices of Garcinia atroviridis fruit in the fermentation process. Results showed that there are no significant differences in most of the biogenic amines including histamine, while there are significant differences in total UCA content, and trans- and cis-UCA contents between the two samples. Differences in the amino acid contents were largely fish-dependent.
Validation of a HPLC method for determination of hydroxymethylfurfural in crude palm oil

Ariffin AA, Ghazali HM, Kavousi P

Food Chem, 2014 Jul 1;154:102-7.
PMID: 24518321 DOI: 10.1016/j.foodchem.2013.12.082

For the first time 5-hydroxymethyl-2-furaldehyde (HMF) was separated from crude palm oil (CPO), and its authenticity was determined using an RP-HPLC method. Separation was accomplished with isocratic elution of a mobile phase comprising water and methanol (92:8 v/v) on a Purospher Star RP-18e column (250mm×4.6mm, 5.0μm). The flow rate was adjusted to 1ml/min and detection was performed at 284nm. The method was validated, and results obtained exhibit a good recovery (95.58% to 98.39%). Assessment of precision showed that the relative standard deviations (RSD%) of retention times and peak areas of spiked samples were less than 0.59% and 2.66%, respectively. Further, the limit of detection (LOD) and LOQ were 0.02, 0.05mg/kg, respectively, and the response was linear across the applied ranges. The crude palm oil samples analysed exhibited HMF content less than 2.27mg/kg.
Fulltext Modelling the effect of water activity and temperature on growth rate and aflatoxin production by two isolates of Aspergillus flavus on paddy

Mousa W, Ghazali FM, Jinap S, Ghazali HM, Radu S

J Appl Microbiol, 2011 Nov;111(5):1262-74.
PMID: 21883729 DOI: 10.1111/j.1365-2672.2011.05134.x

This study was conducted to characterize the growth of and aflatoxin production by Aspergillus flavus on paddy and to develop kinetic models describing the growth rate as a function of water activity (a(w)) and temperature.
Composition and thermal characteristics of Madhuca longifolia seed fat and its solid and liquid fractions

Marikkar JM, Ghazali HM, Long K

J Oleo Sci, 2010;59(1):7-14.
PMID: 20032594

This study was to characterize the seed fat from Madhuca longifolia known as Mee fat and its solid and liquid fractions with the objective of distinguishing them. A sample of Mee fat was partitioned into solid and liquid fractions using acetone as the solvent medium. The isolated fractions were compared to the native Mee fat sample with respect to various physico-chemical parameters using standard chemical methods as well as instrumental techniques such as, gas liquid chromatography (GLC), reversed-phase high performance liquid chromatography (RP-HPLC), and differential scanning calorimetry (DSC). Basic analyses indicated that there were wide variations between the native sample and its fractions with respect to iodine value (IV), and slip melting point (SMP). The cloud point (CP) of the liquid fraction was found to be 10.5 degrees C. Fatty acid compositional analyses showed that the proportion of saturated fatty acids (SFA) such as palmitic and stearic went up in the high-melting fraction (HMF) while in low-melting fraction (LMF) the proportion of unsaturated fatty acid (USFA) such as oleic and lenoleic increased. According to the HPLC analyses, Mee fat had a tiacyl glycerol (TAG) sequence similar to that of palm oil. After fractionation, the solid and liquid fractions obtained were found to have TAG profiles very much different from the native sample. Thermal analyses by DSC showed that Mee fat had two-widely separated high and low melting thermal transitions, a feature which was beneficial for the effective separation of solid and liquid fractions. The thermal profiles displayed by the fractions were clearly distinguishable from that of the native sample.
Determination of trans- and cis-urocanic acid in relation to histamine, putrescine, and cadaverine contents in tuna (Auxis Thazard) at different storage temperatures

Zare D, Muhammad K, Bejo MH, Ghazali HM

J Food Sci, 2015 Feb;80(2):T479-83.
PMID: 25586500 DOI: 10.1111/1750-3841.12752

Scombroid fish poisoning is usually associated with consumption of fish containing high levels of histamine. However, reports indicate that some cases have responded to antihistamine therapy while ingested histamine levels in these cases were low. Potentiation of histamine toxicity by some biogenic amines, and release of endogenous histamine by other compounds such as cis-urocanic acid (UCA) are some hypotheses that have been put forth to explain this anomaly. Very little is known about the effects of storage conditions on the production of both UCA isomers and biogenic amines in tuna. Thus, the production of trans- and cis-UCA, histamine, putrescine, and cadaverine in tuna during 15 d of storage at 0, 3, and 10 °C and 2 d storage at ambient temperature were monitored. The initial trans- and cis-UCA contents in fresh tuna were 2.90 and 1.47 mg/kg, respectively, whereas the levels of putrescine and cadaverine were less than 2 mg/kg, and histamine was not detected. The highest levels of trans- and cis-UCA were obtained during 15 d storage at 3 °C (23.74 and 21.79 mg/kg, respectively) while the highest concentrations of histamine (2796 mg/kg), putrescine (220.32 mg/kg) and cadaverine (1045.20 mg/kg) were obtained during storage at room temperature, 10 and 10 °C, respectively. Histamine content increased considerably during storage at 10 °C whereas trans- and cis-UCA contents changed slightly. The initial trans-UCA content decreased during storage at ambient temperature. Thus, unlike histamine, concentrations of trans- and cis-UCA did not result in elevated levels during storage of tuna.
Changes in urocanic acid, histamine, putrescine and cadaverine levels in Indian mackerel (Rastrelliger kanagurta) during storage at different temperatures

Zare D, Muhammad K, Bejo MH, Ghazali HM

Food Chem, 2013 Aug 15;139(1-4):320-5.
PMID: 23561112 DOI: 10.1016/j.foodchem.2012.12.040

Histamine, putrescine cadaverine and cis-urocanic acid (UCA) have all been implicated or suggested in scombroid fish poisoning. However, there is little information on UCA especially during storage. Changes in their contents during storage of whole Indian mackerel at 0, 3±1, 10±1 for up to 15 days and 23±2°C for up to 2 days were monitored. Fresh muscles contained 14.83 mg/kg trans-UCA, 2.23 mg/kg cis-UCA and 1.86 mg/kg cadaverine. Histamine and putrescine were not detected. After 15 days at 0 and 3°C, trans-UCA content increased to 52.83 and 189.51 mg/kg, respectively, and decreased to <2 mg/kg at the other two temperatures. Storage at 10°C also resulted in an increase in trans-UCA after 3 days, only to decrease after 6 days. The concentration of cis-UCA increased nearly 13-fold after 15 days at 0 and 3°C, decreased at 10°C and remained unchanged at 23°C. Histamine, putrescine and cadaverine levels increased significantly (P value<0.05) at all temperatures especially at 23°C.
Purification and N-terminal amino acid sequence of fructose-6-phosphate phosphoketolase from Bifidobacterium longum BB536

Fandi KG, Ghazali HM, Yazid AM, Raha AR

Lett Appl Microbiol, 2001 Apr;32(4):235-9.
PMID: 11298932

AIMS: The key enzyme in the fructose-6-phosphate shunt in bifidobacteria, Fructose-6-phosphate phosphoketolase (F6PPK; E.C. 4.1.2.22.), was purified to electrophoretic homogeneity for the first time from Bifidobacterium longum (BB536).
METHODS AND RESULTS: A three-step procedure comprising acetone fractionation followed by fast protein liquid chromatography (FPLC) resulted in a 30-fold purification. The purified enzyme had a molecular mass of 300 +/- 5 kDa as determined by gel filtration. It is probably a tetramer containing two different subunits with molecular masses of 93 +/- 1 kDa and 59 +/- 0.5 kDa, as determined by SDS-PAGE.
CONCLUSION: The deduced N-terminal amino acid sequences of the two subunits revealed no significant similarity between them and other proteins when compared to the data bases of EMBL and SWISS-PROT, indicating that this could be the first report on N-terminal amino acid sequence of F6PPK.
SIGNIFICANCE AND IMPACT OF THE STUDY: The data from this study will be used to design oligonucleotide probe specific for bifidobacteria and to study the gene encoded F6PPK.
Fulltext Screening method for detection of immediate amino acid decarboxylases--producing bacteria implicated in food poisoning

Hussain H, Mohd Fuat AR, Vimala B, Ghazali HM

Trop Biomed, 2011 Aug;28(2):351-61.
PMID: 22041756

Assessment of amino acid decarboxylase activity can be conducted using tubed broth or plated agar. In this study, the test was carried out in microtitre plates containing lysine, ornithine, arginine, tyrosine, tryptophan, phenylalanine or histidine as biogenic amine precursors. Møller decarboxylase base broth (MDB) with or without 1% of a known amino acid were added to wells of a 96 well-microtitre plate. The wells were inoculated with Escherichia coli, Klebsiella pneumoniae, Acinetobacter anitratus or Staphylococcus aureus to the final concentration of 6.0 x 10(7) cfu/ml and incubated at 35ºC. The absorbance of the culture broth was read at 570 nm at 0, 1.0, 2.0, 3.0, 4.0, 5.5, 6.5 and 7.5 hour. Comparison of means of A'(570) between 0 hour and a specified incubation time was determined statistically. Positive decarboxylase activities were detected in the media inoculated with E. coli and K. pneumoniae in less than 6 hours. The current method is suitable for immediate producers of amino acid decarboxylase enzymes. It costs less as it uses less amino acid and it has the potential to be used for screening aliquots of food materials for amino acid decarboxylase activities.
Effect of blending and emulsification on thermal behavior, solid fat content, and microstructure properties of palm oil-based margarine fats

Saadi S, Ariffin AA, Ghazali HM, Miskandar MS, Abdulkarim SM, Boo HC

J Food Sci, 2011 Jan-Feb;76(1):C21-30.
PMID: 21535649 DOI: 10.1111/j.1750-3841.2010.01922.x

The ability of palm oil (PO) to crystallize as beta prime polymorph has made it an attractive option for the production of margarine fat (MF). Palm stearin (PS) expresses similar crystallization behavior and is considered one of the best substitutes of hydrogenated oils due to its capability to impart the required level of plasticity and body to the finished product. Normally, PS is blended with PO to reduce the melting point at body temperature (37 °C). Lipid phase, formulated by PO and PS in different ratios were subjected to an emulsification process and the following analyses were done: triacylglycerols, solid fat content (SFC), and thermal behavior. In addition, the microstructure properties, including size and number of crystals, were determined for experimental MFs (EMFs) and commercial MFs (CMFs). Results showed that blending and emulsification at PS levels over 40 wt% significantly changed the physicochemical and microstructure properties of EMF as compared to CMF, resulting in a desirable dipalmitoyl-oleoyl-glycerol content of less than 36.1%. SFC at 37 °C, crystal size, crystal number, crystallization, and melting enthalpies (ΔH) were 15%, 5.37 μm, 1425 crystal/μm(2), 17.25 J/g, and 57.69J/g, respectively. All data reported indicate that the formation of granular crystals in MFs was dominated by high-melting triacylglycerol namely dipalmitoyl-oleoyl-glycerol, while the small dose of monoacylglycerol that is used as emulsifier slowed crystallization rate. Practical Application: Most of the past studies were focused on thermal behavior of edible oils and some blends of oils and fats. The crystallization of oils and fats are well documented but there is scarce information concerning some mechanism related to crystallization and emulsification. Therefore, this study will help to gather information on the behavior of emulsifier on crystallization regime; also the dominating TAG responsible for primary granular crystal formations, as well as to determine the best level of stearin to impart the required microstructure properties and body to the finished products.
Identification of lactic acid bacteria from chili bo, a Malaysian food ingredient

Leisner JJ, Pot B, Christensen H, Rusul G, Olsen JE, Wee BW, et al.

Appl Environ Microbiol, 1999 Feb;65(2):599-605.
PMID: 9925588

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28 degreesC with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg-1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682.

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