The primary objectives of the present work were to produce corncob powder (CCP) from
corncobs and incorporate the CCP into bread formulation in order to develop high fibre bread,
and to investigate the physicochemical and sensory properties of the produced high fibre
bread (HFB). The corncobs were collected and washed before they underwent the grinding
and drying processes. The obtained CCP was incorporated into the bread formulation in three
different proportions (5, 10 and 20%) to partially substitute bread flour in the formulation. All
three bread samples and the control (0% CCP in the formulation) were analysed to obtain their
physicochemical and sensory properties. The incorporation of CCP significantly affected the
texture, colour and volume attributes of the produced breads. Increasing the content of CCP
in the formulation was found to be responsible for firmer, smaller and darker bread loaves as
compared to the composite bread samples. The bread formulation incorporated with 10% CCP
had the highest mean scores (7.00) of overall acceptability among all the other formulations,
and it was comparable to the commercial breads in the current market.
The bioaccessibility property of apigenin from Mangifera indica (Water Lily var.) was
investigated using in vitro gastrointestinal digestion model. Two digestion stages were
simulated namely the gastric and small intestinal digestion by using different enzymes and
physiological conditions that mimicked the digestion process. Following digestion, the
bioaccessible apigenin was analysed using HPLD-DAD-MS. Results showed that the apigenin
fraction in intestinal phase was higher than in gastric phase with amounts 1.03 ± 0.35 mg/100
g DW and 0.50 ± 0.08 mg/100 g DW, respectively. After 1 h exposure to gastric juice, the
bioaccessibility of apigenin was 20.26 ± 3.06% with 79.74 ± 3.06% losses during the digestion,
whereas in intestinal phase, the percentage of bioaccessibility significantly increased to 41.53
± 13.99% and 58.47 ± 13.99% losses after 2 h treatment with pancreatin. It was concluded that
the apigenin in Water Lily mango became bioaccessible, suggesting the absorption possibility
of the compound in the upper part of intestine, which can lead to the health-related outcomes.
The aim of the present work was to analyse the impact of ozone treatment on the physicochemical parameters and antioxidant capacity of citrus fruit juices (orange, lemon and lime) with different juice components (total soluble solids). Each sample was ozonated at different ozone treatment time, between 0 to 30 min with fixed ozone concentration of 600 mg/h. The synergistic effects of ozone treatment and the different types of juice were found to significantly affect the pH, total colour difference (TCD), pectin methylesterase (PME) activity, ascorbic acid (AA) and total phenolic content (TPC) of treated juices, while total soluble solids, turbidity and 2,2-diphenyl- 1-picrylhydrazyl (DPPH) assay were found to be unchanged. It was observed that PME activity decreased with treatment time and this is related to the decrease of juice turbidity (R2 = 0.86) and TCD (R2 = 0.78). Ascorbic acid showed an abrupt decrease in all the juices especially in orange juice with percentage loss of 85%. TPC also showed decreasing trend for all juices with maximum loss of 84.4% in lemon juice after 30 min of ozonation time. The present work also found that lemon juice could retain most of its antioxidant activities (DPPH 98.9%, TPC 96%, AA 86.7%) after 10 min of ozone treatment time in comparison to orange and lime juices.
The effect of transesterification of engkabang (Shorea macrophylla) fat - canola oil (EF35/ CaO65) blend by Mucor miehei lipase (1%, w/w oil) in a solvent-free system was investigated at different time intervals of 6 h, 12 h and 24 h. Compositional changes of the samples withdrawn at specified time intervals while the reaction in progress were analysed by chromatography, whereas the polymorphic forms and thermal properties were analysed by using X-ray diffraction and differential scanning calorimetry, respectively. There were increases in the amounts of monounsaturated and triunsaturated triacylglycerol (TAG) molecular groups with concurrent reductions of the proportions of desaturated TAG molecular groups during different time intervals. This changing TAG composition led to changes in crystallisation behaviour and thermal properties of the samples, reducing some enthalpy values. All samples withdrawn at different time intervals displayed both β' and β type crystal polymorphs even though engkabang fat itself was predominantly β‐type. In terms of melting, solidification and polymorphic properties, the sample withdrawn at 6 h time interval was found to display the closest similarity to lard (LD).
Mangosteen (Garcinia mangostana Linn.) is a highly beneficial fruit, containing potent bioactive compounds such as xanthones. However, the metabolite comparisons of mangosteen pericarp, aril and seed have not been described in detail previously. A comparative approach was undertaken in the present work to evaluate the effects of different ratios of solvent combination in the metabolite extraction of mangosteen. Gas chromatography-based metabolomics approach was performed to evaluate the efficiency of two metabolite extraction methods utilising different solvent extraction ratios (3/1/1 v/v or 2/1/2 v/v of methanol/chloroform/water) in determining the primary metabolite composition of mangosteen fruit tissues (pericarp, aril and seed). Cumulatively, 43 known metabolites were putatively identified from the mangosteen fruit tissues. Due to the higher ratio of polar solvent (methanol and water) used in method 2 as compared to method 1, the former method preferentially extracted a higher number of polar metabolites. Conversely, the higher ratio of methanol solvent in method 1 also contributed to the identification of more alcohol metabolites. Additionally, the multivariate analysis revealed that mangosteen pericarp was mainly localised by ribonic acid, arabinopyranose, β-hydroxypyruvic acid, L-(+)-tartaric acid and galacturonic acid. Meanwhile, thymol-α-D- glucopyranoside and D-ribofuranose contributed to the separation of mangosteen aril, whereas mangosteen seed contained high levels of β-D-galactofuranose, L-threonic acid, butanoic acid, glycoside, malic acid and myo-inositol. Results suggested that the differing solvent ratios can highly influence the types and levels of the extracted metabolites. This finding highlights the influence of metabolite solvent extraction methods towards the end results of the extraction as well as the localisation of primary metabolites in different mangosteen fruit tissues. Hence, the present work is vital in revealing important spatial information of various metabolites toward a better understanding of the mangosteen fruit ripening process.
Local people in Sarawak, Malaysia produce sago starch, commonly referred as lemantak, using traditional method for authentic meals and delicacies. The quality of lemantak degrades with time due to its high moisture content limiting the potential for a wider market, and hence affecting the socio-economy of those whose livelihood depends on sago starch production. The objective of the present work was to evaluate the changes in the properties of traditionally processed dried Sarawak sago starch. In order to achieve this, sago starch was extracted using a well-established traditional process and was dried at 40°C to produce sago starch with moisture contents of 40%, 30%, 20% and 10% wet basis. The effect of moisture content on the physical properties was studied through colour analysis, microscopic analysis, and particle size distribution. Analysis on resistant starch content was also performed. Changes on the hydration and functional properties was monitored by measuring the water absorption index (WAI), water solubility index (WSI), swelling capacity (SC), and gelatinisation behaviour. Lastly, Fourier transform-infrared spectroscopy (FT-IR) was applied to observe the changes in amorphous and crystalline areas. The physical properties analysis showed changes in starch colour and granule surface; but the change on granule size varied. Dried starch with lower moisture content exhibited higher resistant starch, absorption index, and peak temperature, but lower solubility index, swelling capacity, peak viscosity, crystalline index, and amorphous index. It is suggested that moisture content affected the changes in traditionally processed sago starch properties which was influenced by few components namely polyphenol, lipid, amylose-lipid complex, and inter-molecular hydrogen bond.
The concentrations of Cd, As, Pb, Se, Fe, Mn, Zn, and Cu in acid-digested onion samples
were determined by inductively coupled plasma mass spectrometry, and the corresponding
elemental profiles were evaluated by using chemometric techniques. Results from principal
component analysis and hierarchical cluster analysis revealed that the spatial variations were
highly associated with As, Se, Pb, Zn, and Cd, which advocated dominance of the site related
impacts over colour variant of the onions. Such variation pattern could be partly attributed to
the consequences of industrialisation and/or urbanisation. From the safety assessment data,
concentrations of hazardous elements such as As, Cd, and Pb, were found beyond the World
Health Organisation and Food and Agricultural Organisation permissible levels, but within the
Malaysian regulatory limits except for Pb. The presence of elevated levels of toxic elements
beyond the reference limits in the onion varieties could be of health concern if ingested.
Tropical fats such as palm oil (PO) from Elaeis guineensis (oil palm), cocoa (Theobroma cacao
L.) butter (CB), avocado (Persea americana) oil (Avo), palm stearin (PS), and Mee (Madhuca
longifolia) fat (MF) are useful raw materials for the formulation of bakery shortenings. Blending
these fats at differing ratios such as binary [MF:PS (99:1)], ternary [Avo:PS:CB (84:7:9)], and
quaternary [PO:PS:SBO:CB (38:5:52:5)] would lead to fat mixtures as replacement for lard
(LD). In the present work, the influence of these three fat blends and LD on cookie dough
textural properties and cookie quality was investigated. The results showed that the hardness of
cookies was correlated to the hardness of dough, which was influenced by the solid fat content
(SFC). The degree of unsaturation of triacylglycerol molecules also seemed to influence these
parameters. Nevertheless, the cookies of all different types of shortenings did not show any
significant differences with regard to their width and thickness. This could be probably due
to the fact that cookies made from formulated plant-based shortenings and LD expanded
uniformly during baking.
The present work was aimed to develop a new type of yogurt made from a mixture of milk
and soymilk. Balanced Incomplete Block Ranking Test and 9-Point Hedonic Scale were
employed in order to determine the best formulation. The effects of sonication condition (time
and temperature) were evaluated on the developed milk-soymilk yogurt properties (viscosity,
texture, and syneresis). Microscopic photographs were used to check the size distribution of
fat globules. The sensory evaluations showed that milk to soymilk ratio of 3:1 was the best
formulation. Moreover, proximate analysis was carried out in order to determine the nutritional
values of the product. It was found that sonication had positive effects on the yogurt properties
such as viscosity, firmness, cohesiveness, and consistency. However, the syneresis of the yogurt
sample did increase when compared with the control.
The present work aimed at obtaining the optimum combination of stabilisers used in an
instant ice cream formulation. Instant ice cream mixes were formulated using milk protein,
fat, sucrose, stabilisers, emulsifiers and water. A basic formulation for ice cream mix was
prepared according to the process flow of instant ice cream. Three different stabilisers
mixtures, which were carboxymethyl cellulose (CMC), carrageenan, and sodium alginate
used in 14 formulations were studied using mixture design methodology. Physical analyses on
meltdown rate, hardness, melted ice cream viscosity, and overrun were performed. The results
were compared with those of commercial instant ice cream to determine the acceptability and
quality of the final products. From the optimisation study, the recommended combination of
stabilisers was found to be 0.151% CMC and 0.149% sodium alginate. The optimised sample
had a higher viscosity of 0.17 Pa.s than the commercial one (0.16 Pa.s), which corresponded to
higher hardness thus indicating slower melting rate, which is a good texture for ice cream. The
overrun of the optimised sample was 108.33%, which is considered high. The high amount of
air, viscosity, and hardness resulted in a low melting rate of 0.22 g/min, which is desirable for
ice cream consumption. Based on sensory evaluation, the optimised instant ice cream was the
most preferred by panellists as compared to commercial sample.
Kappaphycus alvarezii is a species of red algae, and one of the most important carrageenan
sources for food, cosmetic, and pharmaceutical industries. It is commercially cultivated in the
eastern part of Malaysia. Although K. alvarezii is rich in nutrients, it is limited in its integration
into Malaysian food products. Therefore, the present work was conducted to investigate the
quality characteristics, sensorial attributes, and antioxidant activity of K. alvarezii in Malaysian
food products. Seaweed puree (SP) from K. alvarezii at 10%, 20% and 30% concentrations were
prepared in the formulations of fish sausages, flat rice noodles and yellow alkaline noodles.
Proximate analysis, physicochemical analysis, microbial count, total phenolic content (TPC),
sensory evaluation, and consumer acceptance survey of the formulated food were conducted.
The incorporation of K. alvarezii significantly increased the fibre, moisture, and ash content in
formulated foods. In addition, the TPC content of K. alvarezii food also significantly increased
up to 42 mg GAE/100 g. The presence of SP in food at higher concentration decreased the
microbial counts. Sensory analysis confirmed that only fish sausages added with SP was
overall acceptable as compared to control. Based on customer survey, functional foods that are
“research proven” were the most preferred. In conclusion, K. alvarezii has the potential to be
incorporated in Malaysian food products and developed as functional food.
Palm kernel cake (PKC) proteins were hydrolysed in the presence of seven proteolytic enzymes.
The antioxidant and antihypertensive activities of each protein hydrolysate were evaluated.
Papain-generated protein hydrolysate showed the highest antioxidant effects measured by
radical scavenging activity (65%), iron (Fe)(II)-chelating activity (65%), and antihypertensive
activity (71%). The results revealed a strong correlation between the antioxidant activity of
the protein hydrolysates with angiotensin-converting enzyme (ACE) inhibitory activity (R2
= 0.69 - 0.98), except for trypsin-generated hydrolysate (R2 = 0.22). The most potent protein
hydrolysate was fractionated and profiled using reversed-phase high-performance liquid
chromatography and isoelectric focusing; peptides were subsequently isolated and identified
by tandem mass spectrometry. The individual peptides were evaluated for antihypertension
potential. A positive correlation was identified between radical scavenging activity and Fe(II)-
chelating activity together and ACE inhibitory activity with R2= 0.69 - 0.98. The findings indicate that there was a positive relationship between the antioxidant and antihypertensive activities of protein hydrolysates and bioactive peptides from PKC proteins.
Polyphenol oxidase (PPO) was extracted from lotus (Nelumbo nucifera) root and partially
purified up to 11.51× with a 43.6% yield using aqueous two-phase separation system. The
optimum pH was at 8.0 for both substrates; 4-methylcatechol and pyrogallol. PPO activities
were maximally achieved at 50°C for pyrogallol, and 20°C for 4-methylcatechol. 84% and 71%
loss of relative PPO activities were obtained for pyrogallol and 4-methylcatechol, respectively
following heat inactivation at 90°C for 40 min. Inactivation rate constant (k) values ranged
between 0.88 × 10-2 min-1 to 2.97 × 10-2 min-1 for pyrogallol, and 0.69 × 10-2 min-1 to 2.44 × 10-2min-1 for 4-methylcatechol. The activation energy (Ea) were 75.32 kJ mol-1 and 73.14 kJ mol-1
for pyrogallol and 4-methylcatechol, respectively. PPO activity was strongly inhibited (> 79%)
by ascorbic acid. SDS exhibited the greatest efficiency in activating lotus root PPO.
Plants constitute a major ingredient in traditional or folk medicine. The therapeutic claims made on the use of these traditional medicinal plants range from simple conditions such as fevers and migraines, to more complex diseases such as cancer, metabolic syndrome and diabetes mellitus. The aqueous ethanolic extracts of five medicinal plant species; Cosmos caudatus, Leucaena leucocephala, Momordica charantia, Pereskia bleo and Averrhoa bilimbi were assessed for glucose lowering effect via the in vitro α-glucosidase inhibition assay. Their antioxidant potential, represented by their DPPH radical scavenging activity and total phenolic contents were also measured. The most potent α-glucosidase inhibitory activity was recorded for the leaf extract of C. caudatus with IC50 of 21.90 ± 3.60 μg/mL, followed by L. leucocephala with IC50 value of 30.80 ± 2.50 μg/mL. Momordica charantia, P. bleo and A. bilimbi did not show any significant inhibition of α-glucosidase. Meanwhile C. caudatus also gave the highest DPPH radical scavenging activity with IC50 value of 272.46 ± 8.98 μg/mL, and the highest total phenolic content with a value of 0.263 ± 0.02 g GAE/g DW. The present work provides a priority list of interesting plants for further study with respect to the treatment of diabetes.
The present work was aimed to isolate and characterise collagen from fringescale sardinella (Sardinella fimbriata) waste materials using two extraction methods; acid soluble collagen (ASC) and pepsin soluble collagen (PSC). The physical and chemical properties of extracted collagens were characterised in terms of protein concentration, structural, solubility and morphological properties. The yields of extracted collagen were 7.48 ± 4.84% for ASC and 0.94 ± 0.22% for PSC. The protein concentrations for ASC and PSC were significantly (p < 0.05) lower than commercial collagen (from tilapia scale). Functional groups for extracted collagens such as amide A (3400-3440 cm-1), amide II (1400-1600 cm-1), and amide III (1200-1500 cm- 1) bands were in the same range as commercial collagen. A higher solubility of commercial collagen and ASC was observed under acidic conditions while PSC was highly soluble under alkaline conditions. Morphological study showed that the collagen had a flaky and fibrillary structure. ASC and PSC exhibited similar properties to the commercial collagen, albeit being of lower values. Therefore, the collagen extracted from fringescale sardinella demonstrated potential for use as an alternative collagen from marine sources
The present work aimed to determine the best formulation of mixed drink made from red cabbage and roselle extracts. Six mixed drink formulations were prepared based on different ratios of red cabbage to roselle extracts: F1 (30:20); F2 (35:15), F3 (40:10); F4 (20:30); F5 (15:35) and F6 (25:25). Samples were prepared by pasteurising the mixed drinks with the pre-determined amount of ingredients at 90°C for 5 sec. The pH of roselle extract (2.06 ± 0.02) was found to be more acidic as compared to red cabbage extract (6.38 ± 0.03). This contributed to the low pH in mixed drink formulations (2.68-3.48). Total titratable acidity (TTA) (0.44-0.89% malic acid w/v) and total anthocyanin content (247.99-339.77 mg cyanidin-3-glucoside/L) were shown to increase significantly with increasing roselle extract concentration. Similarly, total soluble solids (TSS) (12.23-12.83°brix) was found to increase significantly with higher ratio of red cabbage extract due to high TSS content (7.67 ± 0.08°brix) in the extract as compared to roselle extract (4.63 ± 0.09°brix). There were significant differences among all the samples in L*, a* and b* values. Mixed drink formulations that contained higher concentration of red cabbage extract were lighter and redder in colour. Significant differences were observed in sweetness, sourness, taste and overall acceptability of drinks, with F3 yielding the highest mean scores for all attributes. Mean score of sensory attributes of the mixed drinks were related to physicochemical properties. Mean scores of all sensory attributes had negative correlation with TTA. Sweetness mean score was positively correlated to the L* value, sourness mean score was positively correlated with pH, L* and a* values but negatively correlated with b* value, and colour mean score had positive correlation with a* value. Therefore, it can be concluded that panellists preferred less sour drinks, which were lighter and redder in colour.β-carotene onto the PKSAC in a model system but yielded the highest desorption efficiency.
Neptunia oleracea Lour. is a tropical plant cultivated in Southeast Asia. It is consumed as vegetable and traditional herb for the treatment of several disorders. The objective of the present work was to isolate the phenolic compounds from N. oleracea, followed by their bioactivity evaluation and quantitative analysis. The ethyl acetate (EtOAc) and methanol (MeOH) fractions of N. oleracea were subjected to various chromatographic techniques to isolate the phenolic compounds. The isolated phenolic compounds were characterised by several spectroscopic methods, including mass spectrometry (MS) and nuclear magnetic resonance (NMR). Then, these compounds were subjected to DPPH free radical scavenging as α-glucosidase inhibitory assays for the evaluation of their activities. Their contents in the fractions were analysed via high performance liquid chromatography (HPLC) quantitative analysis. Five phenolic compounds including quercetin-3-O-β-D-xylopyranoside (1), quercetin-3-O-α-Larabinopyranoside (2), quercetin-3-O-α-L-rhamnoside (3), methylgallate (4) and rutin (5) were isolated from N. oleracea for the first time. Evaluation on the DPPH free radical scavenging and α-glucosidase inhibitory activities of these compounds showed that methylgallate (4) was the most potent antioxidant and α-glucosidase inhibitors among them, with IC50 values of 17.25 and 50.76 μM, respectively. The HPLC quantitative analysis revealed the high content of the quercetin derivatives (compounds 1, 2 and 3) in the EtOAc fraction (ranging from 125.68 to 157.55 μg/mg) and methylgallate (4) in the MeOH fraction (75.25 μg/mg). Comparison of the bioactivities of the isolated phenolic compounds with the fractions indicated their significant contribution for the DPPH free radical scavenging of N. oleracea; while they might be working synergistically for the α-glucosidase inhibitory activity. The results of the present work could help to validate the contribution of phenolic compounds for the studied bioactivities of N. oleracea.
Four types of crude extracts were obtained from the stem bark of Garcinia mangostana from which six xanthone derivatives: α-mangostin, β-mangostin, garcinone D, mangostenol, fuscaxanthone C and dulcisxanthone F were isolated. The structures of these compounds were elucidated and determined using spectroscopic techniques such as MS, 1D and 2D NMR. The in vitro anti-Bacillus assay was performed using the crude extracts as well as α-mangostin and β-mangostin against four Bacillus species; B. subtilis ATCC 6633, B. cereus ATCC 33019, B. megaterium ATCC 14581 and B. pumilus ATCC 14884. The ethyl acetate extract showed strong inhibitory activity against B. subtilis, B. cereus, B. megaterium and B. pumilus in disc diffusion assay with 10.33 ± 0.44 mm, 10.33 ± 0.44 mm, 9.00 ± 0.00 mm and 11.33 ± 0.17 mm inhibition zones, respectively. Nitric oxide inhibition activities indicated that two major compounds (α-mangostin, β-mangostin) exhibited very significant activity in the inhibition of LPS/IFN-γ stimulated RAW 264.7 macrophages with IC50 values of 29.81 ± 0.77 and 11.72 ± 1.16 μM, respectively. The chloroform and ethyl acetate extract of G. mangostana showed very potent activities.
Enzymatic hydrolysis of proteins is an important bioprocess method to prepare bioactive peptides with many functionality and health benefits. The aims of the present work were to prepare and determine the physicochemical characteristics of gelatine hydrolysate from skin of shortfin scad (SSGH) via hydrolysis using alcalase. Analyses on chemical composition, molecular weight by SDS PAGE, protein concentration, amino acid composition, Fourier Transform Infrared Spectroscopic features, and solubility of SSGH were thus performed. The yield of SSGH obtained was 51.01% (d.b.). The chemical compositions of SSGH for moisture, protein, fat, and ash were 13.82%, 90.05%, 1.95%, and 12.48%, respectively. SSGH showed low molecular weight (
Mushrooms have been consumed by mankind for millennia. In Malaysia, there are many species of edible mushrooms which are either cultivated (Agaricus spp., Auricularia spp., Pleurotus spp.) or harvested in the wild (Ganoderma spp., Polyporus spp., Termitomyces spp.). With the advancement of technology, numerous discoveries have been made that elucidated the nutritional (high in fibres, proteins, vitamins; low in fats, cholesterols, sodium) and medicinal (anti-oxidative, anti-hypertensive, neuritogenesis) properties of edible mushrooms, all of which are highly beneficial for the maintenance of human health and well-being. This review thus compiles and documents the available literatures on edible mushrooms reported from Malaysia complete with scientific, English, and vernacular names for future references; provides a comprehensive and updated overview on the nutritional and medicinal properties edible mushrooms reported from Malaysia; and identifies the research gaps to promote further research and development on edible mushrooms reported from Malaysia. Overall, Malaysia is and remains a natural repository for wild and cultivated edible mushrooms. Deeper investigation on their nutritional and medicinal properties will certainly serve as an impetus for economic as well as scientific progress.