Short communication: Determination of lactoferrin in Feta cheese whey with reversed-phase high-performance liquid chromatography

Abstract In the current paper, a method is introduced to determine lactoferrin in sweet whey using reversed-phase HPLC without any pretreatment of the samples or use of a separation technique. As a starting point, the most common HPLC protocols for acid whey, which included pretreatment of the whey along with a sodium dodecyl sulfate-PAGE step, were tested. By skipping the pretreatment and the separation steps while altering the gradient profile, different chromatographs were obtained that proved to be equally efficient to determine lactoferrin. For this novel 1-step reversed-phase HPLC method, repeatability was very high over a wide range of concentrations (1.88% intraday to 5.89% interday). The limit of detection was 35.46μg/mL [signal:noise ratio (S/N)=3], whereas the limit of quantification was 50.86μg/mL (S/N=10). Omitting the pretreatment step caused a degradation of the column's lifetime (to approximately 2,000 samples). As a result, the lactoferrin elution time changed, but neither the accuracy nor the separation ability of the method was significantly influenced. We observed that this degradation could be easily avoided or detained by centrifuging the samples to remove fat or by extensive cleaning of the column after every 5 samples

Exploring the Effect of Ultrafiltration/Diafiltration Processing Conditions on the Lactoferrin and Immunoglobulin G Content of Feta Whey Protein Concentrates

In this paper, the production of powder enriched in lactoferrin (Lf) and immunoglobulin G (IgG) from untreated feta cheese whey is studied. More specifically, the influence of transmembrane pressure (Δp) and temperature on flux and separation ability during ultrafiltration combined with continuous diafiltration is investigated. Two different types of membranes were used, a spiral polyvinylidene fluoride (PVDF) (molecular weight cut-off [MWCO 75 kDa) and a set of 18 cylindrical PVDF membranes (MWCO 100 kDa). For the production of the whey powder, two drying methods were compared: spray and freeze drying. All combinations lead to powder with high total protein content and with a notable content in these two bioactive proteins. However, cylindrical membranes (at a temperature of 20C and a transmembrane pressure of 4 bar) in combination with freeze drying resulted in the highest yield from whey into Lf and IgG and excellent sensory characteristics. Practical Applications Whey powder enriched in the multifunctional proteins lactoferrin and immunoglobulin G have very large potential both as nutrition additives and for pharmaceutical purposes. The systematic study of the parameters affecting all unit operations involved leads to the most efficient and cheapest production. In order to achieve this, the methodology was kept as simple and low cost as possible. This way, a strong tool could be created for the utilization of the cheese-making by-product whey, which still causes large environmental problems

A rapid HPLC method for the determination of lactoferrin in milk of various species

This Research Communication describes the adaptation and testing of an RP-HPLC method, previously tested for the determination of lactoferrin (LF) in whey, for its applicability to determine milk lactoferrin content. Milk samples of various species, namely, ovine, caprine, bovine, donkey and human milk, were tested. The advantage of this RP-HPLC method includes speed and convenience, as it does not include extensive pretreatment or separation steps. A simple pre-treatment step was added in order to remove fat and proteins of the casein family and the samples were tested. The results varied in terms of elution of the LF peak both between the milk of the different species as well as from the initial application on whey. The peak resolution was satisfactory in the cases of ovine, bovine and donkey milk samples while for caprine and human milk an interference with other peaks was observed. Nevertheless, quantification of LF was found possible for all samples. This new application of the modified method will allow the determination of LF in milk samples of the tested species either for everyday analysis or as a useful qualitative screening for presence or absence of LF.status: publishe

Development of a Green Methodology for Simultaneous Extraction of Polyphenols and Pigments from Red Winemaking Solid Wastes (Pomace) Using a Novel Glycerol-Sodium Benzoate Deep Eutectic Solvent and Ultrasonication Pretreatment

In this examination, two glycerol-based deep eutectic solvents (DESs) were tested for their efficiency in the recovery of antioxidant polyphenols and anthocyanin pigments from red grape pomace (RGP). The two DESs synthesized had sodium acetate and sodium benzoate as hydrogen bond acceptors, to test the role of the hydrogen bond acceptor polarity on the extraction performance. Furthermore, the process was enhanced by an ultrasonication pretreatment stage. After initial testing with respect to water content, ultrasonication power and liquid-to-solid ratio, the DES composed of glycerol and sodium benzoate (GL-SBz) was shown to be significantly more efficient than the one made of glycerol and sodium acetate (GL-SAc). Further optimization of the extraction with regard to time and temperature demonstrated GL-SBz to be a highly effective solvent for the production of RGP extracts rich in polyphenols including gallic acid, catechin and quercetin, and pigments including malvidin 3-O-glucoside p-coumarate and malvidin 3-O-glucoside. The extracts produced also had significantly higher antiradical activity and reducing power compared to those generated with aqueous ethanol or water. From this study, evidence emerged regarding the role of the hydrogen bond acceptor nature in the extraction efficiency of polyphenols. The process developed is proposed as a green, high-performing methodology for the production of RGP extracts with enhanced polyphenolic content and antioxidant activity

Glycerol-Based Deep Eutectic Solvents for Simultaneous Organosolv Treatment/Extraction: High-Performance Recovery of Antioxidant Polyphenols from Onion Solid Wastes

Onion solid wastes (OSW) are a food side-stream with high polyphenolic load and distinguished polyphenolic profile. This study was conducted in order to explore a novel methodology of production of polyphenol-enriched extracts with antioxidant properties from OSW, using glycerol and green deep eutectic solvents (DES), composed of glycerol/citric acid and glycerol/sodium acetate. The organosolv process developed was appraised by establishing models based on severity, but also response surface methodology. Using a linear model, it was, for the first time, proposed that there is a direct correlation between the yield of the process in total polyphenols and the combined severity factor. Furthermore, response surface optimization enabled the establishment of linear models to predict the effects of time and temperature on the total polyphenol extraction yield. Out of the solvents tested, the DES composed of citric acid and glycerol was found to provide the highest yield in total polyphenols (87.90 ± 3.08 mg gallic acid equivalents per g dry mass) at significantly higher combined severity. However, the extraction efficiency of this solvent was virtually equal to that of the two other solvents tested. On the other hand, the polyphenolic composition of the extract obtained with the glycerol/citric acid DES was characterized by exceptionally high quercetin concentration. This extract also displayed the highest antioxidant activity. Based on the evidence emerged, it was proposed that OSW polyphenol extraction with the DES glycerol/citric acid could be used for production of extracts enriched in the bioactive flavonoid quercetin, with enhanced antioxidant activity. Moreover, using this green methodology, 27.59 ± 0.09 g of pure quercetin could be recovered out of 1 kg OSW. Thus, this methodology could be employed as a sustainable means of producing quercetin, through valorization of food wastes in a biorefinery context

Exploring the Chemical Composition and Antioxidant Properties of Apricot Kernel Oil

Apricot kernels are known to be rich in bioactive compounds such as polyphenols, which have applications in various fields such as cosmetology and the food industry. However, the extraction of these compounds has not been extensively studied. In this study, we aimed to extract oil from apricot kernels and investigate its composition and antioxidant properties. Samples from two years of apricot cannery by-products were used in the study. We employed a common extraction procedure using hexane as a solvent, followed by an analysis of the oil’s fatty acid composition and determination of its antioxidant properties using several methods. Our results indicated that the oil extracted from apricot kernels is rich in oleic and palmitoleic acids, which exhibit health benefits. As regards the volatile compounds of the oil, 2-methyl propanal, benzaldehyde, and benzyl alcohol were detected as the main compounds. Benzaldehyde was also found to be the main component of the essential oil of the kernel. Furthermore, the oil exhibited low antioxidant activity, as demonstrated by its ability to scavenge free radicals. Overall, our findings suggest that apricot kernels are a valuable source of oil with potential applications in the food and cosmetic industries

Stability of microemulsions containing red grape pomace extract obtained with a glycerol/sodium benzoate deep eutectic solvent

The valorization of red grape pomace is significant as grape is one of the most cultivated fruits worldwide and generated by-product quantities are enormous. For this purpose, numerous encapsulation techniques have been developed. However, the studies on microemulsions composed with deep eutectic solvent extracts are very limited. In this study, red grape pomace extract (RGPE) was first prepared by deep eutectic solvent extraction and characterized by HPLC analysis. Rutin, quercetin, catechin and caftaric acid were identified as the main non-pigment phenolic compounds. The RGPE was further encapsulated in microemulsions (MEs) following a low-energy approach using a mixture of low molecular weight surfactants, and the pseudo-ternary phase diagram was constructed. The physical and antioxidant stability of MEs containing 3–15 wt% RGPE was investigated for a period of 30 days. MEs were stable at an ambient temperature of 25 or 37 °C. The radical scavenging activity of encapsulated RGPE was improved up to 13% compared to the free extract. Our results indicate that microemulsions provide protection of valuable phenolic constituents especially under elevated temperature conditions and can therefore be used as systems for applications in nutraceuticals or cosmetics

Exploring the Effect of Ultrafiltration/Diafiltration Processing Conditions on the Lactoferrin and Immunoglobulin G Content of Feta Whey Protein Concentrates

© 2014 Wiley Periodicals, Inc. In this paper, the production of powder enriched in lactoferrin (Lf) and immunoglobulin G (IgG) from untreated feta cheese whey is studied. More specifically, the influence of transmembrane pressure (Δp) and temperature on flux and separation ability during ultrafiltration combined with continuous diafiltration is investigated. Two different types of membranes were used, a spiral polyvinylidene fluoride (PVDF) (molecular weight cut-off [MWCO 75 kDa) and a set of 18 cylindrical PVDF membranes (MWCO 100 kDa). For the production of the whey powder, two drying methods were compared: spray and freeze drying. All combinations lead to powder with high total protein content and with a notable content in these two bioactive proteins. However, cylindrical membranes (at a temperature of 20C and a transmembrane pressure of 4 bar) in combination with freeze drying resulted in the highest yield from whey into Lf and IgG and excellent sensory characteristics. Practical Applications Whey powder enriched in the multifunctional proteins lactoferrin and immunoglobulin G have very large potential both as nutrition additives and for pharmaceutical purposes. The systematic study of the parameters affecting all unit operations involved leads to the most efficient and cheapest production. In order to achieve this, the methodology was kept as simple and low cost as possible. This way, a strong tool could be created for the utilization of the cheese-making by-product whey, which still causes large environmental problems.status: publishe

Recovery of Natural Antioxidants from Olive Mill Wastewater Using Genapol-X080

Abstract The possibility of applying cloud point extraction (CPE) using Genapol X-080 as surfactant for the separation of phenolic compounds from olive mill wastewater was examined. The ability of the surfactant to recover individual and mixtures of polyphenols and tocopherols in various concentrations from aqueous solutions was tested before its application for the recovery of phenols from olive mill wastewater. Many of the examined individual polyphenols were recovered at high percentage. Especially, in the case of Luteolin, low surfactant concentrations were sufficient for quantitative removal. The recovery appeared proportional to the surfactant concentration. The complete recovery of tocopherols was also possible. Total phenol recovery by simple and successive CPE of olive mill wastewater with various concentrations (2, 5 and 20%, v/v) of Genapol X-080 was up to 89.5%