Abstract: Emulsion formation is unavoidable and can be detrimental to an oil field production. The presence of stable emulsions also reduces the quality of crude oil and causes more problems in the downstream refinery operations, such as corrosion and pipeline pressure drop. Hence, it is important to know the effects of emulsions in the pipeline. Light crude oil was used for the continuous phase in the W/O emulsions where the emulsions pass through a flow loop to test the pressure drop across the pipeline. The results obtained shows that pressure drop increases as water cut is increased until it peaks at the phase inversion of the W/O emulsion between 30% to 40% water cut. Emulsions produced by gradual constrictions show a lower stability as compared to sudden constrictions. Lower stability of emulsions in gradual constriction has the higher influence of pressure drop compared to a sudden sharp decrease in diameter in sudden constriction. Generally, sudden constriction experiences pressure drop of 0.013% to 0.067% higher than gradual constriction of the same ratio. Lower constriction ratio cases cause larger pressure drop ranging from 0.061% to 0.241%. Considering the higher profitability in lower emulsion stability and lower pressure drop at the developed flow region of different constrictions, an optimum design of constriction is found to be gradual constriction with a ratio of 0.5.
Abstract: Millets as a new source of plant protein were not used in food applications due to its poor functional properties. In this study, the effect of high intensity ultrasound (frequency: 20 kHz, with contentious flow) (US) in 100% amplitude for varying times (5, 12.5, and 20 min) on solubility, emulsifying activity index (EAI), emulsion stability (ES), foaming capacity (FC), and foaming stability (FS) of millet protein concentrate (MPC) were evaluated. In addition, the structural properties of best treatments such as molecular weight and surface charge were compared with the control sample to prove the US effect. The US treatments significantly (P
Abstract: Rice bran is normally used as a raw material for rice
bran oil production or sold as feed with a low price. Conventionally,
the protein in defatted rice bran was extracted using alkaline
extraction and acid precipitation, which involves in chemical usage
and lowering some nutritious component. This study was conducted
in order to extract of rice bran protein concentrate (RBPC) from
defatted rice bran using enzymes and employing polysaccharides in a
precipitating step. The properties of RBPC obtained will be compared
to those of a control sample extracted using a conventional method.
The results showed that extraction of protein from rice bran using
enzymes exhibited the higher protein recovery compared to that
extraction with alkaline. The extraction conditions using alcalase 2%
(v/w) at 50 C, pH 9.5 gave the highest protein (2.44%) and yield
(32.09%) in extracted solution compared to other enzymes. Rice bran
protein concentrate powder prepared by a precipitation step using
alginate (protein in solution: alginate 1:0.016) exhibited the highest
protein (27.55%) and yield (6.84%). Precipitation using alginate was
better than that of acid. RBPC extracted with alkaline (ALK) or
enzyme alcalase (ALC), then precipitated with alginate (AL)
(samples RBP-ALK-AL and RBP-ALC-AL) yielded the precipitation
rate of 75% and 91.30%, respectively. Therefore, protein
precipitation using alginate was then selected. Amino acid profile of
control sample, and sample precipitated with alginate, as compared to
casein and soy protein isolated, showed that control sample showed
the highest content among all sample. Functional property study of
RBP showed that the highest nitrogen solubility occurred in pH 8-10.
There was no statically significant between emulsion capacity and
emulsion stability of control and sample precipitated by alginate.
However, control sample showed a higher of foaming capacity and
foaming stability compared to those of sample precipitated with
alginate. The finding was successful in terms of minimizing
chemicals used in extraction and precipitation steps in preparation of
rice bran protein concentrate. This research involves in a production
of value-added product in which the double amount of protein (28%)
compared to original amount (14%) contained in rice bran could be
beneficial in terms of adding to food products e.g. healthy drink with
high protein and fiber. In addition, the basic knowledge of functional
property of rice bran protein concentrate was obtained, which can be
used to appropriately select the application of this value-added
product from rice bran.
Abstract: The process parameters, starch-water ratio (A, (w/v) %), pH of suspension (B), Temperature(C, °C) and Time (D, hrs.)., were optimized for the preparation of starch-lysine conjugate and studying their effect on stability of emulsions by calculating emulsion stability index using response surface methodology. The optimized conditions are pH 9.0, temperature 60oC, reaction time 6 hrs, starch:water ratio 1:2.5, having emulsion stability index was 0.72.
Abstract: The current desire in food and industrial emulsification is the use of natural emulsifiers. Bambara groundnut flour (BGNF) and its starch (BGNS) will serve both emulsifying and nutritional purposes if found suitable. This current study was aimed at investigating the emulsifying properties of BGNF/BGNS. BGNS was extracted from the BGNF. Emulsions were prepared using a wide range of flour-oil-water and starch-oil-water composition as generated through the application of Response Surface (D-optimal) design. Prepared emulsions were investigated for stability to creaming/sedimentation (using the kinetic information from turbiscan) and flocculation/coalescence (by monitoring the droplet diameter growth using optical microscope) over 5 days. The most stable emulsions (one BGNF-stabilized and the other BGNS-stabilized) were determined. The optimal emulsifier/oil composition was 9g/39g for BGNF and 5g/30g for BGNS. The two emulsions had only 30% and 50% growth in oil droplet diameter respectively by day 5, compared to over 3000% in the unstable ones. The BGNF-stabilized emulsions were more stable than the BGNS-stabilized ones. Emulsions were successfully stabilized with BGNF and BGNS.
Abstract: Metal working fluids were used in the preparation of oil in water emulsions. The size of oil droplets were evaluated by using the analysis of video images taken from the zeta potential measurements. The evaluated size distributions for emulsions were also tested by microscopic analysis. In addition, emulsion stabilities were discussed depending on electrolyte concentration and pH. The results showed that the stability of oil emulsions was strongly related to pH and the concentration of CaCl2. However, the same dependency was not observed for NaCl.