Property changes and cholesterol-lowering effects in evening primrose oil-enriched and cholesterol-reduced yogurt

Harnessing the untapped potential of indigenous cow milk in producing set-type yoghurts: case of Thamankaduwa White and Lankan cattle

This research paper assessed textural, microstructural, sensory and colour properties of set-yoghurts produced using milk from two indigenous cattle types, Thamankaduwa White (TW) and Lankan cattle (LC) compared to two generic cattle breeds, Friesian and Jersey. Instrumental texture profile (firmness, adhesiveness, cohesiveness and springiness), colour space (L* a* b*) and scanning electron micrographs of set-yoghurts during 21 d of storage (4 ± 1°C) were evaluated. Sensory quality attributes were evaluated with 40 untrained panellists using a five-point hedonic scale. Set-yoghurts prepared using indigenous cow milk showed higher (P < 0.05) firmness, cohesiveness and apparent viscosity values compared to those prepared using generic cow milk. As revealed by micrographs, set-yoghurts made from TW milk had lesser and smaller void spaces and a dense protein gel network than gels made from LC and the two generic breeds. The gel network made from Friesian milk showed a comparatively larger porous gel structure and thinner protein strands resulting in a weaker gel than other milk gels. The highest lightness (L*) and yellowness (b*) were observed from set-yoghurt produced from Friesian and LC milk, respectively. Set-yoghurts from TW milk had the highest (P < 0.05) sensory scores for all sensory attributes. The lowest sensory acceptance was recorded in set-yoghurt made from Friesian milk. Thus, milk from TW and LC is likely to be suitable in producing set-yoghurts with superior textural, microstructural and sensory properties, compared to milk from Jersey and Friesian. Our results suggest the merits of using indigenous cow milk in producing set-yoghurts and, thereby, prioritizing the preservation of the genetic pool of these indigenous breeds.

The effect of treatment conditions on color characteristics and measure of cholesterol removal from milk by beta-cyclodextrin application

Long-term high cholesterol intake is one of the most critical risk factors of cardiovascular diseases (CVD). As milk and dairy products are rich in cholesterol and are consumed on a large scale, the production of low-cholesterol content products could decrease effectively high cholesterol intake what would be one of the crucial steps in CVD prevention. Thus, this study is aimed at optimization of treatment conditions (mixing speed, time, and temperature) and β-cyclodextrin addition affecting the measure of cholesterol removal in milk. As found, the optimal conditions were identified such as mixing speed 840 rpm, mixing time 10 min, and the temperature of mixing 25 °C while the most effectivity in cholesterol decrease content (98.1%) was observed after 2.0% β-cyclodextrin addition. The cholesterol removal process did not affect considerably the lightness values L* of treated milk, slight differences were noticed in terms of a* and b* color values but ΔE values were statistically insignificant, i.e., the process of cholesterol removal did not affect visual characteristics of treated milk. So, these conditions can be applied for the production of milk base functional foods with the decreased cholesterol content.

Studying the Influence of Apple Peel Polyphenol Extract Fortification on the Characteristics of Probiotic Yoghurt

The aim of the current study was to evaluate the effect of apple peel polyphenol extract (APPE) on the physicochemical and microbiological properties of probiotic yoghurt. Five concentrations of APPE were added in probiotic yoghurt as: (1) CTL, control without APPE; (2) AE1, addition of 1% APPE; (3) AE2, addition of 2% APPE; (4) AE3, addition of 3% APPE; (5) AE4, addition of 4% APPE; and (6) AE5, addition of 5% APPE. The prepared probiotic yoghurt was stored at 4 °C for 21 days and analyzed for physicochemical and microbiological properties. The initial viable count of L. bulgaricus, S. thermophilus, B. lactis and L. acidophilus were similar in all yoghurt samples at day 1. The maximum viability loss of probiotics was observed in CTL (p < 0.05). The lowest viability loss of probiotics was observed in AE5 samples (p < 0.05). The acidity, water holding capacity and viscosity were increased with the addition of APPE. No significant effects were observed on milk fat and total solid contents of probiotic yoghurt with the addition of APPE. The total phenolic contents of probiotic yoghurt increased significantly as 0.59, 0.71, 0.97, 1.18, 1.35 in AE1, AE2, AE3, AE4 and AE5, samples respectively. It was observed that AE3 and AE4 samples had better taste, flavour and colour with good texture. The survival of probiotics and antioxidant activity of the yoghurts were enhanced with the addition of APPE. In conclusion, apple peels could be successfully used as prebiotic in yoghurt with increased viable counts of probiotics.

The Influence of β-Cyclodextrin on the Reduction of Cholesterol Content in Egg and Duck Liver Pâté

The use of β-cyclodextrin (β-CD) to reduce cholesterol is increasing in food research due to its affinity for non-polar molecules such as cholesterol. The objective of this study was to study the ability of β-CD to remove cholesterol in natural egg, powdered egg, and duck liver pâté and its effect on individual fatty acids. A concentration of 5% of β-CD was found to be a suitable amount to remove 80.04 ± 4.96–82.12 ± 5.36% of cholesterol from yolk and powdered eggs and 80.21 ± 5.28% of cholesterol from duck liver pâté. β-CD complexed to cholesterol was precipitated and removed by centrifugation. Individual fatty acid compositions did not differ (p < 0.05) between the controls and the products treated with 5% β-CD.

Use of Fish Oil Nanoencapsulated with Gum Arabic Carrier in Low Fat Probiotic Fermented Milk

Fish oil consists of omega-3 fatty acids which play an important role in human health. Its susceptibility to oxidation causes considerable degradation during the processing and storage of food products. Accordingly, encapsulation of this ingredient through freeze drying was studied with the aim of protecting it against environmental conditions. Gum arabic (GA) was used as the wall material for fish oil nanoencapsulation where tween 80 was applied as the emulsifier. A water-in-oil (W/O) emulsion was prepared by sonication, containing 6% fish oil dispersed in aqueous solutions including 20% and 25% total wall material. The emulsion was sonicated at 24 kHz for 120 s. The emulsion was then freeze-dried and the nanocapsules were incorporated into probiotic fermented milk, with the effects of nanocapsules examined on the milk. The results showed that the nanoparticles encapsulated with 25% gum arabic and 4% emulsifier had the highest encapsulation efficiency (EE) (87.17%) and the lowest surface oil (31.66 mg/100 kg). Using nanoencapsulated fish oil in fermented milk significantly (p<0.05) increased the viability of Lactobacillus plantarum as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents. The fermented milk sample containing fish oil nanoencapsulated with 25% wall material and 4% emulsifier yielded the greatest probiotic bacterial count (8.41 Log CFU/mL) and the lowest peroxide value (0.57 mEq/kg). Moreover, this sample had the highest EPA and DHA contents. Utilizing this nanoencapsulated fish oil did not adversely affect fermented milk overall acceptance. Therefore, it can be used for fortification of low fat probiotic fermented milk.

Effect of Beta Cyclodextrin on the Reduction of Cholesterol in Ewe's Milk Manchego Cheese

Beta-cyclodextrin (β-CD) is a cyclic oligosaccharide consisting of seven glucose units and is produced from starch using cyclodextrin glycotransferase enzymes to break the polysaccharide chain and forming a cyclic polysaccharide molecule. The use of β-CD in food research for reduction of cholesterol is increasing due to its affinity for non-polar molecules such as cholesterol. The aim of this study was to evaluate the feasibility of using β-CD in cholesterol removal from pasteurized ewe’s milk Manchego cheese and evaluate the effect on the main components of the milk, lipids, and flavor characteristics. Approximately 97.6% cholesterol reduction was observed in the cheese that was treated using β-CD. Physicochemical properties (fat, moisture and protein) were not changed by the β-CD treatment, except the soluble nitrogen and non-protein nitrogen that showed slight differences after the treatment. The amount of the different components of the lipid fraction (fatty acids, triglycerides and phospholipids) were similar in cheeses treated and not treated with β-CD. Flavor compound and short chain free fatty acids were not mostly significantly influenced by the effect of the β-CD. β-CD molecules are edible and nontoxic and as a result they can be used safely for cholesterol removal processing in cheese manufacturing. Therefore, the present study suggests that β-CD treatment is an effective process for cholesterol removal from Manchego cheese while preserving its properties.

Promising features of mango (Mangifera indica L.) kernel oil: a review

Mango kernel contains about 15 % good quality edible oil, that is comparable to soybean and cottonseed, which contain about 18-20 % oil. Mango kernel oil (MKO) has lower free fatty acids, carotenoid content and peroxide value, and is usually used without any processing, which is otherwise mandatory for commercial vegetable oils. Palmitic, stearic and oleic acids are the major fatty acids, triglyceride composition and fatty acid profile suggest wide range of trans free options. With 32-36 °C melting point, MKO is solid at room temperature, thus, does not require partial hydrogenation for application in foods. MKO can be used as an alternative of cocoa butter, which is used in chocolates and confectionaries. Total phenolic contents and induction period of MKO is greater than many commercial vegetable oils; thus, it can be used as an alternative of synthetic antioxidants for the preservation of fats and oils. Mangiferin, chlorogenic acid, quercetin and caffeic acid are the major phenolic compounds present in MKO. Functional properties of MKO can be further improved through fractionation, transesterification and interesterification for increased industrial applications.

Rheological and physical properties of yogurt enriched with phytosterol during storage

Phytosterols enriched products are innovative types of functional foods, in which dairy products, like low fat yogurt are ideal vehicles for this functional component. In this study, phytosterol dispersions were prepared using an oil/water (O/W) emulsion. The emulsion was added to yogurt milk. pH, titratable acidity (TA), syneresis, firmness and apparent viscosity of enriched yogurt were determined during storage. Moreover, phytosterols distribution in different parts of enriched yogurt was studied. Results indicated that in enriched yogurt, apparent viscosity and syneresis were lower and firmness was higher compared to the control. Addition of phytosterol to the yogurt had significant effect on acidity. Distribution of phytosterols in different parts of one sample was not uniform. Sensory results showed that there was no significant difference between enriched and control on texture, appearance, flavor and overall acceptance.

Cholesterol extraction from ghee using glass beads functionalized with beta cyclodextrin

Beta-cyclodextrin (β-CD) was covalently immobilized on glass surface. Functionalized glass surface was characterized by X-ray photoelectron spectroscopy (XPS) and elemental analysis. Glass surface functionalized with β-CD was used to remove cholesterol from ghee (clarified butter fat). 78.8 % cholesterol was reduced in 2 h at 25 °C and 170 rpm. Same surface was used repeatedly for 10 cycles and no reduction in cholesterol removal efficiency was observed. Modified glass surface showed almost no degradation in repeated use in cholesterol reduction experiments.

Physicochemical and sensory properties of yogurt enriched with microencapsulated fish oil

Encapsulation of marine omega-3 oil by complex coacervation technique has been introduced as most effective approach to delay its oxidation and extend shelf life of ω(3)-enriched food products. Therefore, to produce enriched yogurt, fish oil containing long-chain omega-3 polyunsaturated fatty acids was microencapsulated in complex coacervates of gelatin/acacia gum. Then, the microcapsules were dried and their surface oil was extracted. Set yogurt was prepared by enriched milk with microcapsules powder. Physicochemical and sensory properties of enriched yogurt were measured during 21 days storage. Acidity, apparent viscosity and water holding capacity of enriched samples were higher and gel strength and amount of whey separation were lower compared to the control. The enriched yogurt samples were more yellowish compared to control. The peroxide value of free and encapsulated fish oil in enriched yogurt samples, after 22 days storage, were increased to 72% and 260%, respectively. Fish oil release of microcapsules was not detected by gas chromatography in extracted oil from enriched yogurt. Sensory results showed that untrained panelists evaluated overall acceptance of enriched yogurt with treated-fish oil microcapsules by lime juice as 'neither liked nor disliked to slightly liked'.

Single- and 14-day repeat-dose toxicity of cross-linked β-cyclodextrin in rats

The present study was carried out to investigate the oral single and repeat toxicity of cross-linked β-cyclodextrin (β-CD) made with adipic acid. Ten each of female and male rats were orally administered a 5000 mg/kg single dose. At this dose, mortality or macroscopic changes of internal organs were not observed. Dose levels 500, 1000, or 2000 mg/kg of β-CD were given daily to 5 each of female and male rats by oral gavage for 14 days. Body and organ weights were not significantly different during the study (P < .05). Hematology and clinical chemistry did not show any toxicity from the cross-linked β-CD. Macroscopic or microscopic changes were not observed between the controls and the treated rats. Based on these results, the cross-linked β-CD did not produce any signs of toxicity or other adverse effects at dose levels up to 2000 mg/kg per d for 14 days.

Properties of Cholesterol-Reduced Butter Made with β-Cyclodextrin and Added Evening Primrose Oil and Phytosterols

The present study was carried out to examine changes in the chemical and sensory properties of butter in which the cholesterol was reduced and to which evening primrose oil (EPO) and phytosterols were added. Crosslinked beta-cyclodextrin (beta-CD) made from adipic acid was used, and approximately 90% of the cholesterol was removed. The color measurement values "L" and "a" were significantly different between the control (butter with no beta-CD treatment and no added EPO and phytosterols) and treatment A (butter treated with 10% crosslinked beta-CD); however, the color values for "L" and "a" were similar. The color value "b" in treatment B (butter treated with 10% crosslinked beta-CD and 5% phytosterols and 3% EPO added) was significantly higher than in the other treatments. The thiobarbituric acid value of treatment B was significantly higher than that of the control and treatment A. Scores for hardness, elasticity, and cohesiveness were significantly lower in the control than in treatment A. Differences in sensory characteristics did not result from the beta-CD treatment but from the addition of EPO and phytosterols. In microscopic examinations, no noticeable differences were found among the treatments, and a smooth texture and a fine, uniform crystalline structure were observed. Results indicated that about 90% of the cholesterol was reduced by crosslinked beta-CD and that the beta-CD treatment itself did not adversely influence the chemical and sensory properties of the butter. However, the addition of EPO and phytosterols to the butter appeared to impair its sensory properties, especially in terms of rancidity and overall acceptability.