Application of non-invasive techniques for quality assessment of dairy powders

About thesis topic: Application of non-invasive methods (hyperspectral imaging, laser scatter imaging, NIR, etc.) to assess the quality of dairy powder

Multi-level partial least squares (MLPLS) applied to near infrared spectra to evaluate the effect of storage in dairy powders

Spectroscopy in the Visible and Near InfraRed spectral range (Vis-NIRS) has been able to detect changes in dairy powder due to storage allowing assessment of product integrity post storage. The physicochemical properties of the dairy powders affected by storage are dependent on type of dairy powder, which can lead to confounding effects on evaluation on Vis-NIR spectra. This study investigates the use of multilevel partial least square discriminant analysis (MLPLS-DA) to detect changes on Vis-NIRS spectra due to short term storage in dairy powders

Spectroscopy in the Visible and Near InfraRed spectral range (Vis-NIRS) to assess chemical and structural properties in dairy powders

Non-invasive spectroscopic techniques applied on dairy powders are able to differentiate product type, capture chemical and structural changes during storage, and detect undesirable quality changes. This shows its potential to be used on-line and in-situ to achieve better process and quality control in dairy industries as well to provide consumer the assurance on product integrity

Application of hyperspectral imaging to assess the quality of dairy powders

Around 95% of New Zealand milk is exported to the rest of the world, mainly as dairy powders. Dairy powders are desired for their convenient storage, ease of transportation, handling and processing, and their uses in product formulations [1]. The quality of dairy powders is often evaluated by their physicochemical and functional attributes such as easy handling [2, 3] (stickiness, flowability, bulk density), rehydration properties [4] (wettability, dispersibility, and solubility), stability [5] (heat stability, oxidative stability, etc.) . Currently, assessing these quality attributes is time consuming and these are conducted ex-situ in the laboratory. There is a need for the development of non-invasive techniques that could be used on-line and in-situ to monitor the powder attributes in order to achieve better process and quality controls

Non-invasive assessment of dairy powder’s functionality

Covers: use and functionality of dairy powders - what determines the functionality of dairy powders Optical properties of dairy powders, interaction of light with dairy powders, non-invasive stereoscopic devices Case stud

Near infrared spectroscopy applied to non-invasive assessment of physical-chemical attributes of dairy powders

Dairy powders are functional ingredients for a variety of foods from confectionery to infant formula. But compositional and structural changes in milk (which are significant across the season) plus variable processing conditions largely affect powder functionality. Ensuring that powder has the right functionality to achieve its required performance is an ultimate goal to the dairy industry. Yet there is no single non-invasive and efficient way to assess powder functionality attributes such as solubility, wettability, bulk density, which are critical during production. In this work a feasibility study using Visible Near InfraRed Spectroscopy (VIS-NIRS) to assess solubility, bulk density, wettability, moisture, water activity, instrumental colour and free-fat of dairy powders is described. The reflectance spectra (VIS-NIRS: 350- 2500 nm) were collected from two different brands of whole milk powder, skim milk powder, bovine infant milk powders (including stages 1, 2, 3); and 1 brand of goat infant milk powder. The samples were stored for 4 weeks for timeline week 0 to week 3, at temperatures of 21 °C (±2 °C) in the closed can to protect them from direct light. Each sample of dairy powder was analysed in duplicate regularly within the 4 weeks. The relationships between the functionality attributes of dairy powders and VIS-NIR spectra was estimated using Partial Least Squares (PLS). The performance of the predictive models was assessed using repeated cross validation based on R2 and root mean square error for cross validation (RMSECV). The R2 value of 0.89 and RMSECV of 0.003 for surface free fat describes the good ability of predictive modelling of VIS-NIR to assess the presence of free fat in dairy powders. Models fitted to predict other functional attributes also showed good performance: Solubility (R2= 0.74, RMSECV= 0.037); bulk density (R2= 0.82, RMSECV= 0.015), wettability (R2= 0.96, RMSECV= 13.43), moisture (R2= 0.84, RMSECV= 0.37), water activity (R2= 0.74, RMSECV= 0.037), colour L* (R2= 0.95, RMSECV= 0.007), a* (R2= 0.423, RMSECV= 0.021) and b* (R2= 0.560, RMSECV= 0.561). Overall these results suggest that VIS-NIRS could be used as tool for the non-invasive assessment of key attributes assessed during dairy powder

Supramolecular characteristics, morphology and functional properties of commercial fat-filled powders from cow milk, goat milk and soy

The quality of a powder is determined by its functional attributes such as wettability, bulk density, flowability and dissolution, which in fat-filled powders, is associated with supramolecular structure. Processing conditions can change powder structure, and during spray drying, specific components may migrate preferentially toward the powder surface changing powder functional attributes. Such structure-function-processing causative relationships are not always clear. This study investigated the association between supramolecular characteristics and powder functional properties. We compared the structure, morphology and functional attributes of commercial nutritional powders prepared from goat and cow milk and soy. We used correlative microscopy of the same samples using confocal laser scanning microscopy (CLSM), Nile Red/Fast Green stains, and scanning electron microscopy (SEM) and compared against functional attribute data (including wettability, insolubility and density) to look for relationships. CLSM showed a clear difference in the fat supramolecular structure between the different powder types. Although all samples had a similar total fat content, soy-based powders revealed a distinct fat distribution with a higher amount of surface free fat. In contrast, bovine-based powders presented a surface with higher protein content, with fat mainly inside of the particle. The free fat analysis, using solvent extraction technique, validated the CLSM results. The amount of free fat was significantly different between powder types with soy-based showing the highest amount and bovine-based having the lowest amount. SEM revealed that bovine-based samples had smoother surfaces, while goat-based samples showed large amounts of small particles on the surface of larger powder particles. The functional properties of the different powder types were also distinct. Soy-based powders presented highest insolubility and water activity and lower bulk and tapped density, while, goat-based powders had the longest wetting time and highest tapped density. The results show a complex interplay between powder structure and functional properties

Non-invasive assessment of dairy powder quality through Near Infrared Spectroscopy

Over 95% of New Zealand milk is exported to the rest of the world, mainly as dairy powders. Dairy powders are frequently used for convenience of transportation, handling, and further processing. The powder characteristics are dependent on the starting raw material, processing parameters and subsequent storage conditions. These powder characteristics determines its physicochemical and functional properties such as wettability, flowability, and oxidative stability. These properties are crucial aspects of the product quality for its end use. Assessing these functional attributes requires several assays performed in the laboratory; hence there is a motivation for the development of non-invasive techniques that could be used on-line to achieve better process control and quality assurance. This study investigates the potential application of spectroscopy in the near infrared (NIR) region for the functionality assessment (bulk and tapped densities, insolubility index, surface free fat and moisture content) of dairy powders during long term storage. Commercial dairy powders varying in batch, brand, type and length of storage (n=360) with a broad range of composition and physicochemical characteristics were investigated. The NIR spectroscopic information was collected via hyperspectral imaging system, benchtop Vis-NIR spectrophotometer and a portable Vis-NIR spectrophotometer. Data collected from non-invasive analysis were correlated with the traditional physicochemical measurement using partial least squares regression (PLSR) models. An external validation data set was collected with a separate set of samples (n=64). Internal validation and external validation both illustrated the robustness of models developed using the benchtop Vis-NIR spectrophotometer and hyperspectral imaging system (Rcv2>=0.8 for insolubility, surface free fat, tapped density and moisture content, and Rcv2>=0.7 for bulk density). The results show that NIR spectroscopy combined with chemometric analysis is a rapid and non-invasive technology for assessing the functionality of dairy powders. The approach also has the potential to be used online for quality assurance of dairy powders

DataSheet_1_Optimum non-invasive predictive indicators for metabolic dysfunction-associated fatty liver disease and its subgroups in the Chinese population: A retrospective case-control study.docx

ObjectiveMetabolic dysfunction-associated fatty liver disease (MAFLD) affects 25% of the population without approved drug therapy. According to the latest consensus, MAFLD is divided into three subgroups based on different diagnostic modalities, including Obesity, Lean, and Type 2 diabetes mellitus (T2DM) MAFLD subgroups. This study aimed to find out the optimum non-invasive metabolism-related indicators to respectively predict MAFLD and its subgroups.Design1058 Chinese participants were enrolled in this study. Anthropometric measurements, laboratory data, and ultrasonography features were collected. 22 metabolism-related indexes were calculated, including fatty liver index (FLI), lipid accumulation product (LAP), waist circumference-triglyceride index (WTI), etc. Logistic regression analyzed the correlation between indexes and MAFLD. Receiver operating characteristics were conducted to compare predictive values among 22 indicators for screening the best indicators to predict MAFLD in different subgroups.ResultsFLI was the best predictor with the maximum odds ratio (OR) values of overall MAFLD (OR: 6.712, 95%CI: 4.766-9.452, area under the curve (AUC): 0.879, P 2DM MAFLD subgroup (OR: 14.725, 95%CI: 3.712-58.420, AUC: 0.958, P ConclusionThe best predictors of overall MAFLD, Obesity, Lean, and T2DM MAFLD subgroups were respectively FLI, LAP, WTI, and FLI.</p

Melanoma cell surface-expressed phosphatidylserine as a therapeutic target for cationic anticancer peptide, temporin-1CEa

<p>We have previously reported that temporin-1CEa, a cationic antimicrobial peptide, exerts preferential cytotoxicity toward cancer cells. However, the exact molecular mechanism for this cancer-selectivity is still largely unknown. Here, we found that the negatively charged phosphatidylserine (PS) expressed on cancer cell surface serves as a target for temporin-1CEa. Our results indicate that human A375 melanoma cells express 50-fold more PS than non-cancerous HaCaT cells. The expression of cell surface PS in various cancer cell lines closely correlated with their ability to be recognized, bound and killed by temporin-1CEa. Additionally, the cytotoxicity of temporin-1CEa against A375 cells can be ameliorated by annexin V, which binds to cell surface PS with high affinity. Moreover, the data of isothermal titration calorimetry assay further confirmed a direct binding of temporin-1CEa to PS, at a ratio of 1:5 (temporin-1CEa:PS). Interestingly, the circular dichroism spectra analysis using artificial biomembrane revealed that PS not only provides electrostatic attractive sites for temporin-1CEa but also confers the membrane-bound temporin-1CEa to form α-helical structure, therefore, enhances the affinity and membrane disrupting ability of temporin-1CEa. In summary, these findings suggested that the melanoma cells expressed PS may serve as a promising target for temporin-1CEa or other cationic anticancer peptides.</p