The impacts on both rheological parameters; Casson yield stress and Casson viscosity were determined. The interactions among blend’s components; xanthan gum (XG), corn starch (CS), glycerin (GL) and their relationship with both flow parameters were also investigated by using D-Optimal mixture design. Three levels of cocoa butter substitution assigned in chocolate production were at 5%, 10% and 15% level with random proportions of each component generated by Design Expert software. An appropriate mathematical model was applied to evaluate each response as a function of the proportions of the components enabling in prediction of future response by using any blend of components. As the incorporation of the blends (XG/CS/GL) in chocolate production was elevated from 5% to 15%, both parameters; viscosity and yield stress of chocolate were gradually increased, as in range 7.819 to 10.529 Pa, and 2.372 to 3.727 Pa.s, respectively. Neither binary nor ternary component-component interaction exhibited synergistic effect. Nevertheless, strongest antagonistic effect on both rheological parameters of substituted chocolate at 5% level and 10% level were respectively observed at ternary interaction region for the former, and at binary interaction area of CS:GL, closer to CS corner as for the latter. This study somehow provides ideas on how component-component interactions influence experimented response.
The aim of this work is to study the effect of hydrocolloids (guar gum, xanthan gum and carboxymethyl cellulose (CMC) on the physical properties and sensory evaluation of ice cream produced in order to investigate the potential of applying fermented glutinous rice (tapai pulut) as a value-added ingredient. The addition of 25% fermented glutinous rice was the most reliable amount to enhance the physical and sensory properties of ice cream when incorporating hydrocolloids. The addition of hydrocolloids significantly (p < 0.05) increased the pH, firmness, overrun, and melting rate of fermented glutinous rice ice cream. The addition of guar gum scored the highest firmness value (5403 g) followed by CMC (4630 g) and xanthan gum (3481g). Fermented glutinous rice ice cream with xanthan gum added, induced a noticeable change in overrun value (62%) while the addition of CMC decreased the melting rate compared to the control. The FTIR spectrum of fermented glutinous rice ice cream with different hydrocolloids containing carboxyl, amide and carbonyl group was appeared at 3362-3379 cm-1 , 1639-1640 cm-1 and 1026-1064 cm-1, respectively. In conclusion, the addition of xanthan gum presented great potential to improve the quality of fermented glutinous rice ice cream produced in terms of its firmness, overrun and melting rate.
Pectin is a heterogeneous branched polysaccharide with complex structure. Microwave-assisted
extraction (MAE) is more efficient in extracting pectin compared to conventional method. The objective of this study was to compare the efficiency of microwave-assisted pectin extraction against conventional extraction method. This study was also to investigate the effect of power level on yield and quality of extracted pectin from jackfruit rinds. Water-based extraction method was performed with the extraction duration for conventional extraction and MAE were 1 h and 10 min, respectively. The temperature of conventional extraction was set at 90°C and the power levels of MAE were 450 W, 600 W and 800 W. High yield of pectin was obtained from conventional extraction (14.59%) and MAE (16.72-17.63%). All quality characteristics determined were found to be insignificant different for pectin extracted from both conventional extraction and MAE except moisture and ash content. Increase in microwave power did not affect yield and quality characteristics of pectin from jackfruit rinds significantly. In conclusion, MAE requires shorter time than conventional extraction in extracting comparable amount and quality of pectin from jackfruit rinds. Microwave-assisted extraction at 450 W was the most effective and economic extraction condition among the different power levels tested.
The aim of this study was to determine the effects of xanthan gum and carrageenan on the
oil uptake and acceptability of banana (Musa acuminate) fritters during repeated deep fat
frying. Banana namely ‘Pisang Awak’ at maturity stage 6 were peeled, cut and dipped into 3
batter formulations containing 1% carrageenan, 1% xanthan gum and a control. The bananas
were deep fried at 170±5°C for 3 minutes in 2.5L cooking oil without oil replenishment for
3 consecutive days. The moisture, oil content, texture, colour and acceptability of the banana
fritters were evaluated at first and every 10th frying cycles. Results indicated that the oil and
moisture content of fried bananas were dependent on frying cycles. The oil content increased
while the moisture decreased with increased in frying cycles. There was significant reduction
(p0.05) in terms of overall acceptance between
treated and untreated. Hence, 1% xanthan gum was effective in reducing oil absorption of
banana fritters without affecting the overall sensory acceptability
Listeria monocytogenes (L. monocytogenes) is a gram positive food-borne pathogen that is able to form biofilm on food factory surfaces. Formation of biofilm makes the bacteria much more resistance to environmental stresses such as disinfectant. The extracellular polymeric matrix (biofilm structure) which is mostly comprised of sticky extracellular polysaccharides (EPS) and proteins can protect bacteria in a harsh condition. The efficiency of four disinfectants on removing L. monocytogenes biofilm was investigated. Five concentration levels (100, 50, 25, 12.5, and 6.25%) of disinfectants were tested. In the microtitre assay, the optical density at 595 nm CV-OD595 value, was used to measure the amount of remained biofilm after 24 h. Results showed that disinfectants did not have significant effect on removing L. monocytogenes biofilm. Formation of L. monocytogenes biofilm significantly decreased the efficiency of disinfectants. Biofilm produced by strain number 9 showed higher resistance to disinfectant. Low concentrations (
The emulsifying properties of extracted okra (Abelmoschus esculentus L.) mucilage at different maturity indices (1, 2 and 3) were studied. The okra mucilage was prepared using water extraction method and was determined their viscosity at different temperature (10, 30, 50 and 70°C), water holding capacity (WHC), oil holding capacity (OHC), as well as their emulsion capacity (EC) and emulsion stability (ES). Results found that okra with maturity index 2 produced the highest percentage yield of mucilage (1.46%) and followed by index 1 (1.10%) and index 3 (0.31%) (p
Tamarind and pineapple fruit pulps and powders were assessed based on their physicochemical properties such as crude protein, crude fibre, fat, ash, moisture content, water activity (Aw), particle shape, particle size distribution, and density. Both of the fruit powders were subjected to a similar spray-drying process with the addition of 10% w/v of maltodextrin. The nutritional value in terms of crude protein (0.33 - 0.60%), moisture content (4.80% - 25.31%), crude fiber (16.92 - 79.92%), and fat (0.40 - 0.63%) for both fruit pulp and powders shows a significant difference at p
The use of component from Ganoderma lucidum as prebiotic source is interesting as the G. lucidum itself was known for more than a decade in the traditional Chinese medicine. In this work, Ganoderma lucidum crude polysaccharides (GLCP) and Polysaccharide-fraction number 2 (PF-2) were used as carbon sources in the fermentation with Bifidobacterium sp. The results showed the potential of prebiotic effect of the G. lucidum extract in batch-culture fermentation based on increment in the growth of bacteria used (0.4 – 1.5 log10 CFU/mL) after 18h fermentation. Fermentation was further done using faecal materials as bacterial inocula and bacterial growth changes were examined using real-time PCR. The results showed the ability of GLCP and PF-2 to support the growth of Bifidobacterium genus with 0.3 and 0.7 log10 cells/ml increased, respectively. Interestingly, Lactobacillus which is known as beneficial bacterial genus also showed growth increment with 0.7 and 1 log10 cells/ml increased. The competition for carbon sources thus inhibits the growth of potentially harmful genus, Salmonella (0.3 and 0.5 log10 cells/ml) in comparison to the control.
The objective of this work was to study the effects of trehalose and maltodextrin on Chinese
steamed bread (CSB) prepared from frozen dough. Trehalose (0.1 and 0.2% w/w) and
maltodextrin (1 and 2% w/w) were added and CSB prepared from the fresh dough and the
frozen dough was characterized in terms of spread ratio, specific volume, staling index and
stress relaxation properties. Upon frozen storage, spread ratio and specific volume of CSB,
and elasticity of the bread crumb were reduced. The extend of deterioration was significantly
reduced with the addition of 0.1% trehalose and 2% maltodextrin. Excessive addition of
trehalose and maltodextrin was found to cause detrimental effects to CSB quality.
The Baobab (Adansonia digitata L.) is a large iconic tree indigenous to Africa where it is found in many countries. The Baobab tree has various uses, as it produces food and non-food products such as medicines, fuel, timber and fodder. This research is focused on the characterization of the Baobab fruit shells in terms of lignin (54.08%), cellulose (24.87%) and hemicellulose (21.05%) content, as well as proximate analysis such as ash content (5.17%), moisture content (6.48%), volatile matter (86.73%) and carbon content (1.22%). This assessment will play a vital role in exploring the benefits of utilizing baobab fruit shells in the production of activated carbon as well as set a foundation for future research.
The advent of green technology has flourished biomolecule applications in medical, pharmaceutical and food products. Unlike synthetic materials, gelatin-polysaccharide matrixes are generally recognized as safe (GRAS). Gelatin-polysaccharide complexes are currently being utilized for the development of nano- and micro-particles, hydrogel, aerogel and films. Gelatin-polysaccharide based materials have offered improved characteristics depending on the type and concentration of polysaccharide and crosslinking agent. Gelatin-polysaccharide based materials function as bioactive compounds entrapment and encapsulation and anti-bacteria. This review provides concise information on the theory and technological applications of gelatin-polysaccharides based materials.
Impacts and relationships on physicochemical properties in dark chocolate produced from different substitution for cocoa butter by Xanthan gum (XG) and Guar gum (GG) blends were determined using D-optimal mixture design. This study involved three levels of substitution which are 5%, 10% and 15% with constrained cocoa butter content and random blend of gums. Linear design models were applied to analyze parameters including texture (hardness) measurement and melting profile of fat crystal. Products experienced undesirable raises of hardness jointly with the increment of gums incorporation across the level of cocoa butter replacement from 5% to 15%. Similar trend was also agreed with the melting behavior of products as their melting point increased with the gradual diminution of cocoa butter. After all, the replacement of cocoa butter using hydrocolloids was deemed possible as there were products whose melting point and hardness fell in the acceptable range.
Spray drying is used widely for converting liquid food products into powder form as the dried powder is known to have a longer shelf life at ambient temperature, convenience to use and low transportation expenditure. In this study, the Sarawak pineapple puree was spray-dried and the characterization of the resulting powder was performed. The process of enzyme liquefaction was optimized with Pectinex® Ultra SP-L and Celluclast® 1.5 L (single and combined treatment) at different concentrations (0–2.5 %) and incubation time (0-2.5 hours). The combined treatment with both enzymes (1.5% v/w Pectinex® Ultra SP-L + 0.5% v/w Celluclast® 1.5 L, 1.5 hour) was found to be the best parameter, which produced purees with the lowest viscosity of 67.98 ± 4.27 cp. Optimization of spray drying process was carried out using different inlet temperatures (150-180°C) and maltodextrin concentrations (15-30 % w/w). Results indicated that the spraydried powder produced at 160°C with 15% w/w of maltodextrin has the highest yield (31.63 %). The spray-dried powder was further characterized for the moisture content (6.00 ± 0.63%), water activity (0.36 ± 0.01 Aw), hygroscopicity (17.35 ± 0.64%), bulk density (0.46 ± 0.04 g/ cm3 ) and solubility (87.33 ± 2.08 seconds). The fruit powder of this study can be incorporated into different fruit added –value products, such as fruit juice, yogurt, jelly and other beverages.
About 60% of world’s commercial enzyme products are proteases, giving promising opportunity
to derive such enzymes sustainably from waste sources. Bromelain is a crude protease occurring
naturally in pineapple, and it possesses properties of benefit for pharmaceutical, medical and food products. The production of bromelain involves a purification stage, normally performed by small-scale conventional operations which lead to high operating cost and low product recovery, while being difficult to scale up and produce polluting by-products. Membrane-based technology offers an alternative to produce high quality purified bromelain in a more efficient and sustainable process. This review identified the current state and future needs for utilising membrane processes for sustainable bromelain production at larger scales. It was found that declining membrane flux due to fouling have been reported, but may be effectively overcome with more appropriate (and advanced) membrane types and/or processing conditions. For example, interactions between macromolecules present in the pineapple derived bromelain mixture (particularly polysaccharides) and the membrane may cause performance limiting fouling, but can be overcome by enzymatic pre-treatment. Membrane fouling can be further reduced by the employment of ceramic membrane filters operating at optimised trans-membrane pressure, cross-flow velocity, feed pH and temperature. Two-stage ultrafiltration together with diafiltration or gas sparging was suggested as a means to reduce fouling and improve enzyme purity. Despite these promising technical findings, the review identified the need for a valid economic assessment to properly guide further work towards purifying bromelain from pineapple waste for sustainable production of commercial proteases.
The effects of alginate-based [sodium alginate, 0-2% (w/v), glycerol, 0-2% (w/v) and sunflower oil 0.025% (w/v)] and gellan-based [gellan, 0-1% (w/v), glycerol, 0-1% (w/v) and sunflower oil 0.025% (w/v)] edible coatings on fresh-cut pineapple were evaluated by response surface methodology (RSM). Weight loss, firmness and respiration rate were considered as response variables. The results showed that for all response variables the RSM models were significantly (p0.05) difference between predicted and experimental values. The overall optimum region predicted by RSM indicated that alginate and gellan-based coatings containing 1.29% (w/v) sodium alginate, 1.16% (w/v) glycerol and 0.56% (w/v) gellan gum, 0.89% (w/v) glycerol were optimized formulations respectively.
Dough mixing and thermal properties including the pasting profiles of various commercial wheat flour (WF)-banana pseudostem flour (BP)-hydrocolloid blends were determined using a farinograph, differential scanning calorimetry (DSC) and a rapid-visco analyser (RVA). The prepared blends were WF, WF substituted with 10% BP (10BP) and 10BP with added 0.8% w/w (flour weight basis) xanthan gum (XG) or sodium carboxymethylcellulose (CMC) (10BPX and 10BPC, respectively). The dough of 10BP and the doughs containing XG or CMC reduced stability and breakdown time compared with the WF dough. All dough containing BP demonstrated greater water absorption and mixing tolerance index values than the WF dough. The substitution of 10% BP into WF and the addition of hydrocolloids did not significantly affect the conclusion temperature (Tc) of the mixture, but did increased the onset temperature (To), peak temperature (Tp) and decreased the gelatinisation enthalpy change (ΔHg) of the blends. Samples of 10BP, 10BPX and 10BPC significantly decreased (p
Starch and hydrocolloids were often used together in food industry to modify the rheological properties with the aim to enhance the starch tolerance to processing conditions. As such, the rheological properties of xanthan gum (XG), carrageenan, high (HMP) and low methoxyl pectin (LMP), with native corn starch (NCS) and modified corn starch (MCS) at different temperature were evaluated in this study. The flow behavior index (n) of corn starch-hydrocolloid mixtures were observed in the range from 0.160 to 0.604 where indicated the shear thinning behavior. The addition of hydrocolloids increased the apparent viscosity of the starch system. NCS mixtures showed consistency index (K) and apparent viscosities (na,100) decreased with increase in the temperature. The addition of XG and carrageenan increased the storage (G’) and loss (G”) moduli. Among the hydrocolloids, the XG addition to the NCS exhibited superior viscoelastic properties as evidenced by the highest G’ and lowest tan δ values. XG was observed capable to increase while pectin reduced the solid-like starch system. This result provides pragmatic data for food engineer in process design and food product development by minimizing the cost of trial and error.
The role of membrane permeabilisation and disruption in the mechanism of action of some polymyxin analogues against Gram-negative organisms is contentious. The effects of polymyxin B (PMB) and its analogue polymyxin B nonapeptide (PMBN) on Escherichia coli envelopes should correlate, but previous work by other workers suggests that PMBN has a different mode of action. This study has reassessed the biochemical techniques used previously and has shown that, in contrast to previous studies, PMBN (a well-characterised antibacterial synergist) readily releases periplasmic proteins and lipopolysaccharide from treated E. coli at subinhibitory concentrations in normal physiological buffer conditions. We conclude that, when tested with appropriate methodology, PMBN closely correlates with the early effects of PMB on the cell envelope of E. coli and this study shows that it is now consistent with the accepted interactions of membrane-active agents against Gram-negative cells.
The vulnerability of probiotics at low pH and high temperature has limited their optimal use as nutraceuticals. This study addressed these issues by adopting a physicochemical driven approach of incorporating Lactobacillus plantarum LAB12 into chitosan (Ch) coated alginate-xanthan gum (Alg-XG) beads. Characterisation of Alg-XG-Ch, which elicited little effect on bead size and polydispersity, demonstrated good miscibility with improved bead surface smoothness and L. plantarum LAB12 entrapment when compared to Alg, Alg-Ch and Alg-XG. Sequential incubation of Alg-XG-Ch in simulated gastric juice and intestinal fluid yielded high survival rate of L. plantarum LAB12 (95%) at pH 1.8 which in turn facilitated sufficient release of probiotics (>7 log CFU/g) at pH 6.8 in both time- and pH-dependent manner. Whilst minimising viability loss at 75 and 90 °C, Alg-XG-Ch improved storage durability of L. plantarum LAB12 at 4 °C. The present results implied the possible use of L. plantarum LAB12 incorporated in Alg-XG-Ch as new functional food ingredient with health claims.
The water-soluble bioactive polysaccharides can contribute to the health benefits of Lycium barbarium fruit. However, the structure characteristics of these polysaccharides remain unclear yet. An important polysaccharide (LBPA) was isolated and purified from L. barbarium in this work. It was identified by chemical and spectroscopic methods as arabinogalactan with β-d-(1→6)-galactan as backbone, which was different to any reported polysaccharides from this species before. This arabinogalactan was comprised of Araf, Galp, GlcpA and Rhap with a molar ratio of 9.2:6.6:1.0:0.9. The side chains, including α-l-Araf-(1→, α-l-Araf-(1→5)-α-l-Araf-(1→, β-l-Araf-(1→5)-α-l-Araf-(1→ and α-l-Rhap-(1→4)-β-d-GlcpA-(1→6)-β-d-Galp-(1→, were linked to β-d-(1→6)-galactan at O-3. The putative structure was drawn as below. The molecular weight was determined to be 470,000g/mol by gel permeation chromatography.