Assessing the use of different chemometric techniques to discriminate low-fat and full-fat yogurts

Physicochemical Characterization of Yogurt Fortified with Microencapsulated Cinnamon (Cinnamomum zeylanicum) and Its Effects on Metabolic Syndrome Induced in Rabbits (Oryctolagus cuniculus)

Chronic noncommunicable diseases are a global health problem causing increased rates of mortality and sick leaves, which can be reduced by controlling dyslipidemia and hyperglycemia. Experimental and clinical studies have demonstrated the antidiabetic, lipid-lowering, antiobesogenic, anti-inflammatory, and antihypertensive properties of cinnamon; therefore, its use in yogurt can help reverse the effects of these diseases. Our study aims to evaluate the effect of a microencapsulated aqueous extract of cinnamon (Cinnamomum zeylanicum) (MCE Cz) incorporated in a yogurt drink on metabolic syndrome (MS) in a rabbit (Oryctolagus cuniculus). Physicochemical, microbiological, and proximal chemical characterization; total phenol, flavonoid, and 2,2-diphenyl-1-picrylhydrazil activity quantification; intestinal bioaccessibility; sensory analysis; MS induction through diet; and treatment with 5, 10, and 20 mg/kg of flavonoids contained in the MCE Cz were performed to help evaluate morphological, biochemical, and lipid peroxidation measurements in the liver and heart. The results show that the addition of MCE Cz in the yogurt modified the yogurt texture, increased its adhesiveness and firmness, and imparted a characteristic cinnamon color and biological value by providing intestinally bioaccessible antioxidants with antioxidant potential by reducing lipoperoxidation in the liver and heart after treatment. MCE Cz reduced the weight of the animals by up to 38.5% and the abdominal circumference by 29%. Biochemically, it decreased glucose levels by 24.38%, total cholesterol levels by 69.2%, triglyceride levels by 72.69%, and low-density lipoprotein levels by 89.25%; it increased high-density lipoprotein levels by 67.08%. Therefore, adding MCE Cz in doses of 5 and 10 mg of flavonoids in drinkable yogurt can be an alternative to preparing functional foods with physicochemical attributes and biological properties that can be consumed at all stages of life without undesirable effects. Moreover, it can act as a potential adjuvant in the treatment of comorbidities related to MS.

Statistical Methods for the Analysis of Food Composition Databases: A Review

Evidence-based knowledge of the relationship between foods and nutrients is needed to inform dietary-based guidelines and policy. Proper and tailored statistical methods to analyse food composition databases (FCDBs) could assist in this regard. This review aims to collate the existing literature that used any statistical method to analyse FCDBs, to identify key trends and research gaps. The search strategy yielded 4238 references from electronic databases of which 24 fulfilled our inclusion criteria. Information on the objectives, statistical methods, and results was extracted. Statistical methods were mostly applied to group similar food items (37.5%). Other aims and objectives included determining associations between the nutrient content and known food characteristics (25.0%), determining nutrient co-occurrence (20.8%), evaluating nutrient changes over time (16.7%), and addressing the accuracy and completeness of databases (16.7%). Standard statistical tests (33.3%) were the most utilised followed by clustering (29.1%), other methods (16.7%), regression methods (12.5%), and dimension reduction techniques (8.3%). Nutrient data has unique characteristics such as correlated components, natural groupings, and a compositional nature. Statistical methods used for analysis need to account for this data structure. Our summary of the literature provides a reference for researchers looking to expand into this area.

Non-Fat Yogurt Fortified with Whey Protein Isolate: Physicochemical, Rheological, and Microstructural Properties

The demand for low- and non-fat products has recently increased due to the health problems, such as obesity, diabetes, and cardiovascular diseases, that have resulted from high-fat products. However, the reduction in fat can affect the quality of products adversely. The objective of this work was to explore the potential of whey protein isolate (WPI) in improving the quality of non-fat yogurt prepared using skim milk powder (SMP). Yogurt mixes (standardized at 14% total solids) were formulated using SMP as a milk base enriched with WPI. The SMP was replaced by WPI in the yogurt mixes at a rate of 3, 5, 7, and 9%. Full-fat and non-fat set-style yogurts were prepared from whole milk and skim milk, respectively, as controls. Yogurts were fermented at 43 °C to get a pH of 4.6 and stored at 4 °C for the next day. The texture, microstructure, rheological characteristics, and sensory properties of the yogurt samples were studied. The incorporation of WPI increased the water holding capacity to 50% as compared to the non-fat control. This improved the rheological properties while the yogurt viscosity increased in direct proportion with increasing the WPI. The firmness of yogurt was inversely proportional to the increase in WPI, which resulted in 180 g firmness when 9% WPI was added to the non-fat yogurt formulations. Yogurts’ microstructure improved by the addition of WPI. The non-fat yogurt incorporated with 3 and 7% WPI had comparable sensory and textural characteristics to the full-fat yogurt. WPI can be used as a fat replacer to develop low-fat yogurt with desired features. WPI may be a natural and economical ingredient for producing low- and non-fat fermented dairy food products.

Building a novel classifier based on teaching learning based optimization and radial basis function neural networks for non-imputed database with irrelevant features

This work presents a novel approach by considering teaching learning based optimization (TLBO) and radial basis function neural networks (RBFNs) for building a classifier for the databases with missing values and irrelevant features. The least square estimator and relief algorithm have been used for imputing the database and evaluating the relevance of features, respectively. The preprocessed dataset is used for developing a classifier based on TLBO trained RBFNs for generating a concise and meaningful description for each class that can be used to classify subsequent instances with no known class label. The method is evaluated extensively through a few bench-mark datasets obtained from UCI repository. The experimental results confirm that our approach can be a promising tool towards constructing a classifier from the databases with missing values and irrelevant attributes.

Chemometric approach based characterization and selection of mid-early cauliflower for bioactive compounds and antioxidant activity

The present study was aimed to analyse bioactive compounds (total phenolics, ascorbic acid and sinigrin) and antioxidant activity in 14 mid-early cauliflower genotypes. Significant differences (pb 0.05) were observed among the genotypes for all bioactive compounds and antioxidant activity. Total phenolics content of curd were ranged from 20.36 to 48.93 mg gallic acid equivalent (GAE) 100 g-1 fresh weight (FW) which showed 2.5 times variation. The ascorbic acid content was maximum in DC522 (88.53 mg 100 g-1 FW) followed by Pusa Sharad (65.64 mg 100 g-1 FW) while minimum in DC310 (39.62 65.64 mg 100 g-1 FW). Wide variation was observed for cupric reducing antioxidant capacity and ferric reducing antioxidant power ranging from 9.04 to 20.83 mg GAE 100 g-1 FW and 13.11 to 26.31 mg GAE 100 g-1 FW, respectively. Sinigrin was found to be highest in DC306 (39.50 µmol 100 g-1 FW) for leaf and in DC326 (36.93 µmol 100 g-1 FW) for curd sample. The cauliflower genotypes were classified based on chemometric approaches namely principal component analysis (PCA) and agglomerative hierarchical clustering (AHC). The first two principal components (PC1 and PC2) explained 50.62% and 23.28% of total variance, respectively. The AHC as revealed by heat map classified cauliflower genotypes into four main groups based on measured traits. The information is useful for developing varieties and/or hybrids rich in bioactive compounds and antioxidant activity.

Sensory, rheological and chemical characteristics during storage of set type full fat yoghurt fortified with barley β-glucan

β-Glucan, is a soluble dietary fiber and is obtained from number of sources including cereals. It possesses the nutraceutical characteristics and acts as functional bioactive ingredient in the fermented dairy product including yoghurt. In this concern, β-glucan isolated from barley having purity of (91.52%) was incorporated in different proportions (0.5, 1, 1.5 and 2%, w/v) during the full fat yoghurt preparation. The analysis of β-glucan carried out initially, indicated that the viscosity, water binding capacity, swelling power and solubility values were 92 Pa s, 3.17 g/g, 18.50 g/g and 3%, respectively, whereas, the total antioxidant activity obtained in terms of DPPH free radical scavenging activity was 27%. Based on these characteristics β-glucan extract had been considered as the choicest material for set type products like yoghurt. Thereafter, physiochemical, rheological and sensory characteristics of β-glucan incorporated yoghurt were evaluated during 1st, 7th and 14th days of refrigerated storage. Addition of β-glucan significantly (p ≤ 0.05) improved whey separation (syneresis), viscosity, texture profile and sensory characteristics during storage. The TPA characteristics such as hardness, cohesiveness and resilience of yoghurt samples improved significantly during storage with the incorporation of β-glucan whereas, β-glucan added yoghurt obtained higher consistency coefficient (K), thus, indicated a thicker and compact texture. Sensory analysis of stored yoghurt indicated that yoghurt samples in the present study containing even higher (1.5-2%) β-glucan level had obtained the higher average overall acceptability (8.1 to 8.3 on 9-point scale) score as compared to a low fat yoghurt containing lower β-glucan level (0.5%) reported in the literature.

Alginate Trisaccharide Binding Sites on the Surface of β-Lactoglobulin Identified by NMR Spectroscopy: Implications for Molecular Network Formation

β-lactoglobulin (BLG) is a promiscuous protein in terms of ligand interactions, having several binding sites reported for hydrophobic biomolecules such as fatty acids, lipids, and vitamins as well as detergents. BLG also interacts with neutral and anionic oligo- and polysaccharides for which the binding sites remain to be identified. The multivalency offered by these carbohydrate ligands is expected to facilitate coacervation, an electrostatically driven liquid-liquid phase separation. Using heteronuclear single quantum coherence NMR spectroscopy and monitoring chemical shift perturbations, we observed specific binding sites of modest affinity for alginate oligosaccharides (AOSs) prepared by alginate lyase degradation. Two different AOS binding sites (site 1 and site 2) centered around K75 and K101 were identified for monomeric BLG isoform A (BLGA) at pH 2.65. In contrast, only site 1 around K75 was observed for dimeric BLGA at pH 4.0. The data suggest a pH-dependent mechanism whereby both the BLGA dimer-monomer equilibrium and electrostatic interactions are exploited. This variability allows for control of coacervation and particle formation of BLGA/alginate mixtures via directed polysaccharide bridging of AOS binding sites and has implication for molecular network formation. The results are valuable for design of polyelectrolyte-based BLG particles and coacervates for carrying nutraceuticals and modulating viscosity in dairy products by use of alginates.

Yogurt and whey beverages available in Brazilian market: Mineral and trace contents, daily intake and statistical differentiation

Mineral and trace elements (Ca, Fe, K, Mg, Na, Pb, Cd, Cr, Cu, and Mn) in commercial strawberry-flavored yogurts and fermented whey beverages in Brazil were investigated. K, Ca, Na, Mg and Fe concentrations ranged from 1.6 to 1.4, 1.4 to 1.1, 0.74 to 0.68, 0.16 to 0.11, and 0.01 mg g-¹ for yogurts and whey beverages, respectively. Similar concentrations of the minerals were observed for both products, except Mg (0.16 mg g-¹ in yogurts and 0.11 mg g-¹ in whey beverages). Cd, Cr, Cu, Mn, and Pb was found below the detection limit (21.4 to 94.1 μg g^-1), demonstrating safety levels for consumption. Regarding the mineral daily intake, consumption of 100 g of the product has relevance for calcium in infants (>40%) and children between 4 and 8 years (>13%), and a greater contribution of yogurt over whey beverage was observed. PLSDA model suggested that Mg analytical determination should be performed to ensure the identity of the product.

Discrimination of Brazilian lager beer by 1H NMR spectroscopy combined with chemometrics

¹H NMR spectroscopy combined with chemometrics was employed to discriminate lager beer samples from two different classes, according to their style and information provided on the label. Partial replacement of barley malt by adjuncts is a common practice adopted by large breweries, which can lead to a decrease in diastatic power, requiring the use of exogenous enzymes. For this reason, small variations in the spectral profile can occur in the carbohydrates region. Many studies have focused on differentiating beers according to type and brewing process. However, there have no studies concerning the discrimination of beers of the same type that differ only in style, using ¹H NMR spectroscopy. In this study PCA (first three components explained 81.5% of the dataset variability), PLS-DA and SIMCA models proved to be powerful tool with predict power higher than 90% for distinguishing lager beers based on the raw materials employed in the brewing process.

Rapid classification of heavy metal-exposed freshwater bacteria by infrared spectroscopy coupled with chemometrics using supervised method

Rapid, cost-effective, sensitive and accurate methodologies to classify bacteria are still in the process of development. The major drawbacks of standard microbiological, molecular and immunological techniques call for the possible usage of infrared (IR) spectroscopy based supervised chemometric techniques. Previous applications of IR based chemometric methods have demonstrated outstanding findings in the classification of bacteria. Therefore, we have exploited an IR spectroscopy based chemometrics using supervised method namely Soft Independent Modeling of Class Analogy (SIMCA) technique for the first time to classify heavy metal-exposed bacteria to be used in the selection of suitable bacteria to evaluate their potential for environmental cleanup applications. Herein, we present the powerful differentiation and classification of laboratory strains (Escherichia coli and Staphylococcus aureus) and environmental isolates (Gordonia sp. and Microbacterium oxydans) of bacteria exposed to growth inhibitory concentrations of silver (Ag), cadmium (Cd) and lead (Pb). Our results demonstrated that SIMCA was able to differentiate all heavy metal-exposed and control groups from each other with 95% confidence level. Correct identification of randomly chosen test samples in their corresponding groups and high model distances between the classes were also achieved. We report, for the first time, the success of IR spectroscopy coupled with supervised chemometric technique SIMCA in classification of different bacteria under a given treatment.

Implementation of chemometrics in quality evaluation of food and beverages

Conventional methods for food quality evaluation based on chemical or microbiological analysis followed by traditional univariate statistics such as ANOVA are considered insufficient for some purposes. More sophisticated instrumental methods including spectroscopy and chromatography, in combination with multivariate analysis-chemometrics, can be used to determine food authenticity, identify adulterations or mislabeling and determine food safety. The purpose of this review is to present the current state of knowledge on the use of chemometric tools for evaluating quality of food products of animal and plant origin and beverages. The article describes applications of several multivariate techniques in food and beverages research, showing their role in adulteration detection, authentication, quality control, differentiation of samples and comparing their classification and prediction ability.

Assessing the effects of different prebiotic dietary oligosaccharides in sheep milk ice cream

The objective of this study was to assess the effects of different prebiotic dietary oligosaccharides (inulin, fructo-oligosaccharide, galacto-oligossacaride, short-chain fructo-oligosaccharide, resistant starch, corn dietary oligosaccharide and polydextrose) in non-fat sheep milk ice cream processing through physical parameters, water mobility and thermal analysis. Overall, the fat replacement by dietary prebiotic oligosaccharides significantly decreased the melting time, melting temperature and the fraction and relaxation time for fat and bound water (T₂₂) while increased the white intensity and glass transition temperature. The replacement of sheep milk fat by prebiotics in sheep milk ice cream constitutes an interesting option to enhance nutritional aspects and develop a functional food.

Characterization of yogurts made with milk solids nonfat by rheological behavior and nuclear magnetic resonance spectroscopy

The effect of adding milk solids nonfat (MSNF) on the physical properties and microstructure of yogurts was investigated. The physical properties of fat free yogurt, fat free with MSNF yogurt, whole fat yogurt, and whole fat with MSNF yogurt were analyzed using shear viscosity, viscoelasticity, and texture analysis. The two yogurts with MSNF had higher consistency coefficient (K), storage modulus (G′), yield stress, and hardness. To gain insight into the multiphase system, nuclear magnetic resonance (NMR) and brightfield microscope images were acquired. The addition of MSNF significantly modified NMR relaxation time; T₁ values were reduced significantly. Brightfield microscope images showed that the size of the protein network of the two yogurts with MSNF added was greater than that of the two yogurts without MSNF added. The microstructural information supported the physical information. The results showed that the increase in MSNF contributed positively to strengthening the physical/mechanical properties of yogurt.

Corn Crisps Enriched in Omega-3 Fatty Acids Sensory Characteristic and its Changes During Storage

Extruded cereal snacks are usually deficient in protein, mineral ingredients, valuable fatty acids. With the rise of health awareness among consumers, food manufacturers and scientists are pressed to take measures in order to develop new functional/health-beneficial foods. The aim of this work was to manufacture extruded crisps enriched with α-linolenic acid (obtained from linseed oil) and to observe whether storage of the product for the period of 6 months would cause its disqualification, primarily due to its sensory properties and secondarily due to its chemical properties. The research demonstrated that the addition of linseed oil to corn crisps at the amount of 5 % enables to obtain functional corn crisps containing over 2 g of ALA in a portion of 100 g even after 6 months of storage at room temperature. ALA-enriched crisps maintain the original sensory profile after 6 months of storage and their sensory profile is similar to the profile of crisps without the addition of linseed oil if they are packed in barrier packaging filled 100 % with argon. Therefore, they may be a healthier alternative to typical corn crisps.

Fatty acids and fat-soluble vitamins in ewe's milk predicted by near infrared reflectance spectroscopy. Determination of seasonality

The aim of the present work was to determine the fatty acid and fat-soluble vitamin composition and the season of ewe's milk production using NIR spectroscopy. 219 ewe's milk samples from different breeds and feeding regimes were taken each month over one year. Fatty acids were analyzed by gas chromatography, and retinol and α-, and γ-tocopherol by liquid chromatography. The results showed that the quantification was more accurate for the milk dried on paper, except for vitamins. Calibration statistical descriptors on milk dried on paper were good for capric, lauric, myristic, palmitoleic, stearic and oleic acids, and acceptable for caprilic, undecanoic, 9c, 11tCLA, ΣCLA, PUFA, ω3, ω6, retinol and α-tocopherol. The equations for the discrimination of seasonality was obtained using the partial least squares discriminant analysis (PLSDA) algorithm. 93% of winter samples and 89% of summer samples were correctly classified using the NIR spectra of milk dried on paper.

Effect of Different Cooking Methods on the Composition of Intramuscular Fatty Acids of Hyla Rabbit

The influence of three cooking methods (stewing, microwaving and Aluminium (Al) foil-baking) was evaluated on the content of intramuscular lipid and the composition of intramuscular fatty acids of Hyla rabbit. The percentage of intramuscular lipid in cooked-longissimus dorsi (LD) (dry weight %) were in the order mentioned below: microwaving > foil-baking > stewing. All treated samples showed decrease in the proportion of polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA), whilst increase in the proportion of saturated (SFA) and n-6/n-3 value during processing. All of the cooked samples had the n-6/n-3 ratio within the recommended range (5-10). By the analysis of partial least squares regression (PLSR), the microwaving treatment was better to keep the stability of unsaturated fatty acids (UFA), whilst the long-time Al foil-baking did the most serious damage to UFA, especially the PUFA. In addition, the heating method showed greater influence on the samples than the processing time. The shorter processing time was better to retain the intramuscular PUFA of Hyla rabbit, especially the LC-PUFAs (C20-22). Considering all the factors, microwaving showed the superiority in reserving the composition of intramuscular fatty acids of Hyla rabbit.

Impact of Altitudes and Habitats on Valerenic Acid, Total Phenolics, Flavonoids, Tannins, and Antioxidant Activity of Valeriana jatamansi

The changes in total phenolics, flavonoids, tannins, valerenic acid, and antioxidant activity were assessed in 25 populations of Valeriana jatamansi sampled from 1200 to 2775 m asl and four habitat types of Uttarakhand, West Himalaya. Significant (p < 0.05) variations in total phenolics, flavonoids, valerenic acid, and antioxidant activity in aerial and root portions and across the populations were observed. Antioxidant activity measured by three in vitro antioxidant assays, i.e., 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) (ABTS) radical scavenging, 2,2'-diphenyl-1-picryylhydrazyl (DPPH) free radical scavenging, and ferric-reducing antioxidant power (FRAP) assays, showed significant (p < 0.05) differences across the populations. However, no clear pattern was found in phytochemicals across the altitudinal range. Among habitat types, (pine, oak, mixed forest, and grassy land), variation in phytochemical content and antioxidant activity were observed. Equal class ranking, neighbor-joining cluster analysis, and principal component analysis (PCA) identified Talwari, Jaberkhet, Manjkhali, and Khirshu populations as promising sources with higher phytochemicals and antioxidant activity. The results recommended that the identified populations with higher value of phytochemicals and antioxidants can be utilized for mass multiplication and breeding program to meet the domestic as well as commercial demand.

Clustering analysis of different hop varieties according to their essential oil composition measured by GC/MS

This study describes the analysis of total hops essential oils from 18 cultivated varieties of hops, five of which were bred in Lithuania, and 7 wild hop forms using gas chromatography-mass spectrometry. The study sought to organise the samples of hops into clusters, according to 72 semi-volatile compounds, by applying a well-known method,

Development of a novel yoghurt based on date liquid sugar: physicochemical and sensory characterization

The addition effect of date liquid sugar (DLS, 1-9 % v/v) to yoghurt milk on the physical (colour, firmness and syneresis), chemical (pH, total titratable acidity (TTA), total phenolic content (TPC) and antioxidant activity), rheological (viscosity and flow behaviour), and sensory attributes was scrutinized. Results showed that the pH value decreased by increasing DLS concentration from 1 to 6 %, while the TTA decreased with an increase in DLS from 6 to 9 % (p < 0.05). The whey syneresis, firmness and viscosity values were considerably influenced by the DLS content and acidity of the yoghurts (p < 0.05). A noticeable increase in antioxidant activity and TPC was found by the increasing DLS content (p < 0.05). Yoghurts containing 6 % v/v DLS also had the lowest syneresis and the highest firmness among the different samples. Moreover, a pseudoplastic rheological behaviour was detected for all the produced yoghurts. An increase in DLS concentration of manufactured yoghurts led to an increase in a, b and total colour difference (TCD) values and a decrease in L value (p < 0.05). The sensory evaluation revealed that there was no significant different in the colour scores. However, the used panelists determined the yoghurt supplemented with 6 % DLS had the highest scores for other investigated attributes.