Properties of lime peel pectin as mainly influenced by ethanol and protein-based purification methods.

BACKGROUND: Lime peel, obtained from juice factory waste, is considered as a source of pectin. Lime peel pectin samples, extracted by three extraction procedures of 90 °C heating for 120 min, 90 °C heating for 90 min and then 32 min of ultrasound, and 80 °C heating for 60 min and then 22 min of ultrasound, and purified by two methods using ethanol and sodium caseinate (SC), were prepared and characterized. RESULTS: The results showed that the purification method significantly affected the lime pectin samples properties. Pectin samples purified with SC had a transparent and film-like appearance, whereas the ethanol-purified pectin samples showed an amorphous and opaque appearance. Pectin samples purified with ethanol showed higher extraction recovery (approximately 20%), whereas the lowest pectin yield was observed for the purification with SC (approximately 10%). Although SC purification did not enhance the pectin yield, it diminished the level of 'non-pectin' components and resulted in purer pectin. The bands at 1045-1076 cm-1 , relating to neutral sugars, had higher intensities in ethanol-purified pectin samples, indicating their higher sugar contents. Also the samples purified with SC exhibited more thermal stability, probably as a result of the presence of protein in their structure. CONCLUSION: In the present study, under the same or varying extraction conditions, the most important element distinguishing pectins in terms of appearance, physicochemical, thermal and Fourier transform infrared characteristics was the type of purification method. Purification with SC may result in pectins with more non-esterified galacturonic acids from the homogalacturonan fraction. © 2023 Society of Chemical Industry.

Physicochemical characteristics of beverage emulsions containing crocetin as a functional ingredient of saffron.

This study aimed to investigate the physicochemical properties of beverage emulsions containing crocetin as a functional ingredient. The effect of different concentrations of gum Arabic (GA; 1-4%), various types of oils (10% sunflower or sesame oil containing 0.1% of crocetin) in the presence of xanthan gum (XG; 0.1%) were studied using a general full factorial design. The dependent variables were pH, opacity, size index, stability index (determined in accelerated and storage conditions), particle size, and steady shear rheological measurements. The main effects of GA concentration were significant (p < 0.001) on all of the physicochemical characteristics. However main effects of oil types were only significant (p < 0.001) on the mean diameter size, size index, and consistency coefficient (k) of prepared crocetin beverage emulsions. Results suggested sunflower oil may be more suitable for formulating a beverage emulsion containing crocetin because of the smaller mean particle size and lower size index.

Mayonnaise main ingredients influence on its structure as an emulsion.

Mayonnaise has a great potential for research and development. Today, consumers are seeking for healthier and natural food products. Generally, it is a blend of oil, egg, salt, lemon juice or vinegar and texture improvers which make its structure as oil in water emulsion. Each of mentioned ingredients has huge effects on mayonnaise emulsion quality. This paper presents information about how these components can change the mayonnaise rheological, stability and sensory attributes.

Effect of washing, soaking and pH in combination with ultrasound on enzymatic rancidity, phytic acid, heavy metals and coliforms of rice bran.

Simultaneous reduction in activity of fat destabilizing enzymes (lipase and lipoxygenase), contaminants heavy metals (As, Cd, Pb, and Hg), antinutrient phytic acid and hazardous coliforms in rice bran was investigated. Application of washing, soaking the washed sample at different pH values (2, 6 and 9) alone or in combination with ultrasonication were examined. While washing was beneficial, its low efficiency acquired further treatment, which was prevailed by application of acidic pH and ultrasound (28 kHz) treatments. Free fatty acids and peroxide value, as indicators of enzymes activity, implied the effectiveness of treatments with adverse impact of sonication on peroxide value. Remarkably, reduction of dominant heavy metals (As, Pb and Zn) and phytic acid were synergistically facilitated by sonication. Coliforms growth was inhibited at pH 2 even at the absence of ultrasonic treatment. Evidently, combination of acidic pH and ultrasound is a practical approach to improve rice bran stability and safety.

Concentrated O/W emulsions formulated by binary and ternary mixtures of sodium caseinate, xanthan and guar gums: rheological properties, microstructure, and stability.

The effects of xanthan gum (XG) (0, 0.3, 0.6 wt%), guar gum (GG) (0, 0.3, 0.6 wt%) and XG:GG mixtures (0.3-0.3, 0.3-0.6, 0.6-0.3 and 0.6-0.6 wt%) on the physical stability of sodium caseinate (CN) stabilized concentrated O/W emulsions (φoil = 0.6) were examined. The emulsion stability, microstructure, droplets size distribution, and rheological properties were evaluated. The findings showed that with increasing total gum concentration up to 0.6% droplets size and emulsion instability significantly decreased (p < 0.05). The emulsion containing a ternary mixture of CN:XG:GG at total gum concentration (0.6%) with a mixing ratio of 0.3:0.3 XG:GG exhibited the best stability with the highest ESI value (98.3%). Above the critical concentration, an excessive increase in storage modulus led to a significant increase in droplet size and emulsion instability. In brief, concentrated emulsions stabilized by binary and ternary mixtures (CN/XG/GG) may be applicable in special food like heavy cream and as a template for fabricating oleogels.

Oleogel production based on binary and ternary mixtures of sodium caseinate, xanthan gum, and guar gum: Optimization of hydrocolloids concentration and drying method.

We report the optimization of oleogel formulation based on sodium caseinate (CN, 0-4 g/100 g), xanthan gum (XG, 0-1 g/100 g), guar gum (GG, 0-1 g/100 g), and drying method (freeze and oven drier) using response surface methodology to achieve the desired oil binding capacity, textural, and rheological attributes. All the selected responses were successfully fitted by a quadratic model with determination coefficient values higher than .95 with the exception of firmness values which was fitted by linear model. There were considerable increases in all the responses for the samples containing ternary mixtures of protein-gum (CN:XG:GG) as well as binary mixtures (CN:GG and CN:XG) compared to samples containing protein or gums alone due to the synergistic effect of CN and gums on formation of highly ordered and strong gel network. Regression modeling demonstrated that freeze drying method led to significantly greater structure recovery values than those of oven drying method. The best formulation was the freeze dried oleogel containing 4 g/100 g CN, 0.43 g/100 g XG, and 0.98 g/100 g GG. Results showed that fabrication of oleogels with at least 94.5 g/100 g sunflower oil and characteristics similar to industrial shortening is feasible.

Effects of tocopherol, rosemary essential oil and Ferulago angulata extract on oxidative stability of mayonnaise during its shelf life: A comparative study.

The purpose of this study was to investigate the effects of tocopherol, rosemary essential oil and ferulago on oxidative stability of mayonnaise during storage. Their efficacy was also compared with tertiary butylhydroquinone (TBHQ) and the control group. During the primary oxidation stage, tocopherol was more efficient than TBHQ, while in the secondary oxidation stage it was the same as other antioxidants. At end of storage, samples with added rosemary essential oil and ferulago extract showed peroxide value (2.29 and 2.80 meq O2/kg oil), anisidine value (11.83 and 12.23), hexanal and heptanal concentration (510.2, 589.9 and 76.6, 75.2 ng/g), respectively, which were meaningfully less than those of the control sample (10.44 meq O2/kg, 18.32, 1339.8 ng/g, and 225.5 ng/g, respectively). Based on the overall results, tocopherol and rosemary essential oil can be recommended as replacement for TBHQ. However, further evaluation needs to be performed on the organoleptic properties of Ferulago extract.

Characterization of sodium caseinate/Hydroxypropyl methylcellulose concentrated emulsions: Effect of mixing ratio, concentration and wax addition.

The effects of mixing ratio (1:1, 2:1 and 4:1 sodium caseinate: Hydroxypropyl methylcellulose, CN:HPMC), HPMC concentration (0, 0.6 and 1.2 wt%), CN concentration (0, 1.25 and 2.5) and beeswax addition (3%) on the physical stability of concentrated O/W emulsions (φoil = 0.6) were investigated. The emulsion stability, particle size distribution, microstructure and rheological properties were measured. The results showed that emulsion stability was significantly improved with increasing HPMC concentration (pvalue < 0.05). The samples with the highest and the lowest biopolymers concentration at mixing ratio of 2:1 had the highest and the lowest ESI (98% and 48%), respectively. In addition, the most stable sample had the smallest volume mean diameter and approximately desirable rheological properties. The beeswax addition considerably improved rheological properties whereas increased droplets diameter and emulsion instability. In summary, concentrated emulsions stabilized by caseinate/Hydroxypropyl methylcellulose complex may be useful for application in particular food such as heavy cream, mayonnaise, oleogels and pharmaceutical products.

Microencapsulation of microbial canthaxanthin with alginate and high methoxyl pectin and evaluation the release properties in neutral and acidic condition.

Canthaxanthin (CX) is an orange-red keto-carotenoid with high antioxidant activity. This functional pigment is sensitive to oxygen, light, pH and heat. In this study, CX was produced by the Dietzia natronolimnaea HS-1 and was encapsulated in Alginate (Alg) and Alg-high methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method to developed resistant microparticles among acidic and neutral pHs. Results showed that initial CX concentration had a significant influence on total CX (TCX), surface CX (SCX), microencapsulation efficiency (EE) and particles size. The highest EE% for Alg (60.21 ±â€¯0.18) and Alg-HMP (70.60 ±â€¯0.68) were obtained with CX initial concentration of 11 and 18 µg/mg, respectively. Alg microparticles showed smaller size compare to Alg-HMP microcapsules. Presence of CX in microparticles and good antioxidant activity was confirmed by FT-IR spectroscopy and DPPH assay, respectively. CX in vitro release was 66% and 49% in acidic condition and 76% and 50% in neutral condition for Alg and Alg-HMP, respectively. Thus, Alg-HMP-CX18 microparticles were selected to be used in both neutral and acidic foods such as milk and fermented milks products as an antioxidant and a colorant agent.

Using ß-cyclodextrin and Arabic Gum as Wall Materials for Encapsulation of Saffron Essential Oil.

Saffron essential oil has a pleasant aroma and medicinal activities. However, it is sensible into the environmental condition. Therefore, it should be protected against unwanted changes during storage or processing. Encapsulation is introduced as a process by which liable materials are protected from unwanted changes. In the present study, different ratios (0:100, 25:75, 50:50, 75:25, and 100:0) of ß-cyclodextrin (ß-CD) and arabic gum (GA) were used as wall martial for encapsulation saffron essential oil. In order to calculate of loading capacity (LC) and encapsulation efficiency (EE), and release (RE), safranal was determined as indicator of saffron essential oil using GC. According to the results, the highest LC and EE were related to the mixture of ß-CD/GA at a 75:25 ratio. In contrast, the lowest encapsulate hygroscopicity (EH) and RE were observed when only ß-CD was applied as wall material (P≤0.05). Comparing the differential scanning calorimetry (DSC) thermograms of the control and encapsulate of ß-CD/GA (75:25) confirmed encapsulation of saffron essential oil. Scanning electron microscopy (SEM) images with high magnifications showed the rhombic structure that partially coated by GA. The mixture of ß-CD/GA at a 75:25 ratio can be recommended for saffron essential oil encapsulation.

Effect of extraction process on composition, oxidative stability and rheological properties of purslane seed oil.

Purslane seed oil could be considered as potential nutritious oil due to its desirable fatty acid composition and other biological active compounds. In this study the effect of three extraction procedure including solvent extraction, cold pressing and microwave pretreatment (MW) followed by cold pressing on oil yield, physicochemical properties, oxidative stability and rheological behaviors of oil was investigated. Solvent extracted oil had the highest extraction yield (72.31%). Pretreatment by microwave before cold press extraction resulted in an increase in extraction yield, total phenolic compound (TPC) and antioxidant activity. Cold press extracted oil had the lowest oxidative stability (4.64h). This property was greatly enhanced by microwave irradiation, so that the longest oxidative stability was found in MW-cold press extracted oil with 9.67h. Furthermore, all extracted oils demonstrated Newtonian flow behaviors. MW-cold press extracted oil had the greatest apparent viscosity and highest sensitivity to temperature changes (Ea=29.18kJ/mol-1).

Industrial Application of Different Heat Treatments and Cream Fat Contents for Improving the Spreadability of Butter.

BACKGROUND: Individual factors, which interfere in the continuous churning, were manipulated to enhance the rheological properties and chemical composition of butter. This process leads to achieve softer; more spreadable, and ultimately healthier product for consumers. In addition it could prevent hardening of texture especially in winter. METHODS: Firstly, Pasteurized cream with different fat contents (40 & 45% fat) was passed through heat treatments, and then it was injected to a continuous churn. Textural and melting behavior and fatty acid composition of butter were analyzed. RESULTS: Increasing the fat content of cream (from 40 to 45 %) and holding time (from 3h to 5h) in mid-temperature (18 ºC) and reducing the churning temperature (from 12 ºC to 10 ºC), resulted in soft butter texture and improved butter spreadability. Loss Tangent (tan δ) was increased from 0.11 to 0.74 (T=15 ºC;f=1Hz). The melting temperature of butter was decreased from 36ºC to 32ºC and total trans fatty acid content was decreased from 3.2 % to 1.87 %. CONCLUSION: It was concluded that such heating process (which has been studied and reported in patents) absorbs the low- SFC fats of the cream, integrates them into the butter texture a softer and more spreadable product.

A comparative study on the in vitro antioxidant activity of tocopherol and extracts from rosemary and Ferulago angulata on oil oxidation during deep frying of potato slices.

There is a tendency towards the use of natural antioxidative substances due to toxic effects of synthetic antioxidants. The purpose of this research was to evaluate the effects of tocopherol and extracts from rosemary and ferulago on oxidation in a mixture (1:1, w/w) of sunflower seed oil and palm olein, during deep frying of potato slices. Besides the control groups, tertiary butylhydroquinone (TBHQ) served as a standard for comparison. The DPPH radical scavenging activities of extracts followed the order of rosemary10% > rosemary1% > rosemary0.1 % > ferulago 10 % > ferulago 1 % > ferulago 0.1 %. Frying performance of antioxidants were tested with regards to primary (peroxide value (PV)) and secondary (anisidine value (AnV), free fatty acids (FFA), total polar compounds (TPC) and volatile oxidation compounds such as hexanal and heptanal) oxidation products and by sensory evaluation. After frying process, rosemary extract treatment exhibited PV (1.2 meq O2/kg), FFA content (0.124 %), TPC (12.2 %), hexanal concentration (62.4 ng/g) and heptanal concentration (73.8 ng/g), which were significantly equal or sometimes less than those of TBHQ treatment ((1.23 meq O2/kg), (0.123 %), (12.6 %), (64.4 ng/g) and (74.1 ng/g), respectively). Whilst the ferulago extract showed higher PV (2 meq O2/kg) than the control sample, it was efficient in delaying secondary oxidative changes. Tocopherol markedly retarded primary stage but its activity fell down toward secondary oxidation products. The overall results of this research suggest that rosemary extract may be a good natural alternative to TBHQ, but further studies are necessary to investigate the use of ferulago extract.

Surface structure smoothing effect of polysaccharide on a heat-set protein particle gel.

This work investigates surface properties of a protein particle gel and effects of polysaccharide on the surface microstructure of such a protein gel. Whey protein isolate (WPI) was used as the primary gelling agent, and a polysaccharide (xanthan) was investigated for its surface smoothing effects. The surface properties of heat-set WPI gels with and without the presence of xanthan (0, 0.05, and 0.25%) were characterized using a surface friction technique. The surface friction force of a gel against a stainless steel substrate was found to be highly dependent on the sliding speed for all three gel samples, and the addition of xanthan caused a general reduction of surface friction. The gel containing no xanthan has the largest surface friction and behaved in the most load-dependent manner, whereas the gel containing 0.25% xanthan has the lowest surface friction and showed the least load dependency. It was inferred that the WPI gel containing no xanthan has the roughest surface among the three samples and the presence of xanthan leads to a smoother surface with probably a thinner layer of surface water. Surface features derived from surface friction tests were confirmed by surface microstructure observation from confocal laser scanning microscopy (CLSM) and environmental electron scanning microscopy (ESEM). Surface profiles from CLSM images were used to quantify the surface roughness of these gels. The mean square root surface roughness R(q) was calculated to be 3.8 +/- 0.2, 3.0 +/- 0.2, and 1.5 +/- 0.2 microm for gels containing 0, 0.05, and 0.25% xanthan, respectively. The dual excitation images of protein and xanthan from CLSM observation and images from ESEM observation indicate a xanthan-rich layer at the surfaces of the xanthan-containing gel samples. We speculate that the creation of the outer surface of a particle gel is based on a different particle aggregation mechanism from that leading to network formation in the bulk.