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Τρίτη 6 Αυγούστου 2019

Chemical profiling and functional properties of dietary fibre rich inner and outer bracts of culinary banana flower

Abstract

The present study endeavoured to evaluate the nutritional, phytochemical and functional properties of outer and inner bracts of culinary banana flower which is a by-product of banana production. Both outer and inner bracts were found to be rich in dietary fibre (61.13 and 66.22%, respectively) along with other chemical compositions including proximate, minerals, and antioxidant-rich phenolics both free and bound. In addition, the functional properties including glucose dialysis retardation index (GDRI) of outer and inner bracts were also studied. The outer and inner bracts exhibited total polyphenols 7.56 and 9.44 mg phenols/g dry sample, respectively. The polyphenol profile by HPLC, revealed the presence of significant amount of free and bound phenolics in both outer and inner bracts. Functional properties of these dietary fibres-rich fractions of culinary banana flower exhibited lower bulk density, higher water-holding capacity, oil-holding capacity, and water-swelling capacity in outer and inner bracts than cellulose. The outer and inner bracts showed relatively higher GDRI compared to control and cellulose. The results revealed that both the outer and inner bracts of culinary banana flower are rich source of dietary fibre along with high antioxidant activity and could be one of the promising functional ingredients for low-calorie and high-fibre food product.

A critical review of analytical methods for determination of curcuminoids in turmeric

Abstract

Turmeric (Curcuma longa) is one of the most important ingredients in Indian and Chinese cuisine. Curcuminoids and volatile oils present in turmeric are known for their functional and nutraceutical properties. Health benefits attributed to curcuminoids have resulted in their wide utilization in food and pharmaceutical formulations. Therefore, characterization and estimation of the curcuminoids in fresh/dry turmeric, food and nutraceutical products are essential for their quality control during processing and storage. To meet the demand for analytical methods of curcuminoids, several methods have been developed for their quantification in turmeric powder and food formulations. In the present review, various analytical methods (spectrophotometric, chromatographic, capillary electrophoresis and biosensor techniques) which are used for monitoring curcuminoids have been thoroughly summarized and discussed. The spectrophotometric method is not useful when individual components of curcuminoids are required. Mobile phase optimization, the broadness of spots, plate-to-plate variations are significant limitations for TLC and HPTLC methods. Many analysts believe that HPLC method is the best choice for curcuminoids determination because of its rapid analysis. Spectrofluorimetry and Electrochemical methods are the more advanced methods with high sensitivity as well as rapid analysis. However, the selection of analytical method for curcuminoids analysis depends on the type of sample matrix, purpose of the analysis and limit of detection and limit of quantitation of the method.

Changes in physicochemical characteristics and oxidative stability of pre- and post-rigor frozen chicken muscles during cold storage

Abstract

The objective of this study was to investigate the effects of rigor state on physicochemical characteristics and the oxidative stability of chicken leg and breast muscles as a function of freezing time. Breast and leg muscles were excised from 24 broiler chickens at 30 min or 1.5 h postmortem (PM), frozen overnight at − 75 °C immediately, and then stored at − 20 °C for 90 days to measure the meat quality traits. Results showed that longer freezing led to deterioration of meat quality with higher deterioration for post-rigor frozen muscles. Pre-rigor frozen muscles had higher pH, water holding capacity (around 90%), and sarcomere length with a lower thaw and cook loss than post-rigor frozen muscles. The Warner–Bartzler shear force (WBSF) values for chicken leg and breast muscles were insignificant (except pre-rigor leg muscles which had significantly higher WBSF value only at 90th day of storage). The lightness (L*) value increased significantly with increasing storage for all samples. Post-rigor muscles had significantly higher TBARS values (0.62 mg MDA/kg) than the pre-rigor muscles. The leg muscles had better physicochemical characteristics compared to breast muscles, except for the cook loss. Therefore, immediate freezing (prior to onset of rigor) could be an effective way to minimize the quality deterioration of frozen chicken muscles.

Functionality of Mozzarella cheese analogues prepared using varying protein sources as influenced by refrigerated storage

Abstract

The functional properties (shredability, meltability, fat leakage, stretchability) of Mozzarella Cheese Analogue (MCA) prepared using acid casein (ACMCA), rennet casein (RCMCA) and their admixture (ARCMCA) were monitored with those of Natural Mozzarella Cheese (NMC) during refrigerated storage. The shredability of analogues was superior over such attribute of NMC. The MCAs had good shredability up to 28 days, while that of NMC started deteriorating from 21 days onwards. The meltability of both NMC and MCAs improved with advancement of storage; the extent of increase in meltability during span of 35 days period was 2.65, 2.85, 2.78 and 2.63 for NMC, ACMCA, RCMCA and ARCMCA respectively. The stretch value of the MCAs exhibited an increase up to 21 days of refrigerated storage followed by decline up to 35 days, whereas NMC exhibited a linear increase in stretch value with advancement of storage till 35 days. There was a steady decline in the fat leakage in case of any of the MCAs with advancement in storage period; the difference in the values of fat leakage up to 35 days was to the tune of 1.50 cm2, 1.39 cm2 and 1.43 cm2 for ACMCA, RCMCA and ARCMCA respectively. Conversely, NMC exhibited linear increase in fat leakage with progressive storage up to 35 days. It is concluded that MCAs had better functional stability as compared to NMC during refrigerated storage. Amongst MCAs, ARCMCA performed better in terms of baking qualities than those prepared using AC or RC alone. MCAs had better storage stability as compared to NMC.

Characterization and classification of wines according to geographical origin, vintage and specific variety based on elemental content: a new chemometric approach

Abstract

A highly informative chemometric approach using elemental data to distinguish and classify wine samples according to different criteria was successfully developed. The robust chemometric methods, such fuzzy principal component analysis (FPCA), FPCA combined with linear discriminant analysis (LDA), namely FPCA-LDA and mainly fuzzy divisive hierarchical associative-clustering (FDHAC), including also classical methods (HCA, PCA and PCA-LDA) were efficaciously applied for characterization and classification of white wines according to the geographical origin, vintage or specific variety. The correct rate of classification applying LDA was 100% in all cases, but more compact groups have been obtained for FPCA scores. A similar separation of samples resulted also when the FDHAC was employed. In addition, FDHAC offers an excellent possibility to associate each fuzzy partition of wine samples to a fuzzy set of specific characteristics, finding in this way very specific elemental contents and fuzzy markers according to the degrees of membership (DOMs).

Synthesis, characterization and cellular mineral absorption of nanoemulsions of Rhododendron arboreum flower extracts stabilized with gum arabic

Abstract

To assess the cellular mineral uptake and oxidative stability of flower extract, a nanoscale gum arabic stabilized Rhododendron arboreum flower extract emulsion was formulated. Four different concentrations of flower extract (1–5%) were used for the optimization of the nanoemulsion. A significant (P < 0.05) difference was observed in average droplet size (43.51–55.87 nm) of the nanoemulsion. FTIR spectrum confirmed mainly C=C, aliphatic C–H, aliphatic and aromatic galacto-proteins, and polymeric-OH groups present in nanoemulsion. Smooth type of nanoemulsion was confirmed by inverted light microscopy. Ionic strength was evaluated and significant (P < 0.05) increase in particles size was attributed, whereas significant (P < 0.05) decrease in zeta potential was observed by increased NaCl concentration. Iron and calcium showed a non-significant difference in terms of mineral bioavailability. Calcium revealed significantly higher cellular uptake (52.11%) in comparison with iron (50.25%) and zinc (45.32%) during transwell assay. Higher cellular iron uptake unveiled a satisfactory amount of ferritin content

Determination of 17β-estradiol in commercial pasteurized and sterilized milk samples in Mashhad, Iran

Abstract

Due to nutritional facts of milk in human life, the quality assessment of dairy products is of the utmost importance. The aim of the current study was to determine the 17β-estradiol level in commercial pasteurized and sterilized milk brands in Mashhad, Iran. In this regard, 160 samples including 80 pasteurized (40 high-fat and 40 low-fat) and 80 sterilized milk (40 high-fat and 40 low-fat) of widely used brands from different supermarkets were collected. The mean level of 17β-estradiol was 8.2 ± 0.59 pg/ml. The mean amount of estradiol was found to be 7.6 ± 0.47, 7.9 ± 0.45, 8.6 ± 0.63, and 8.9 ± 0.54 pg/ml for the low-fat pasteurized, low-fat sterilized, high-fat pasteurized and high-fat sterilized milk, respectively. There was no significant difference between the amount of estradiol in pasteurized and sterilized milk. As expected, the level of estradiol was statistically higher in high fat milks than that of low-fat milks. Considering the levels of 17β-estradiol measured here and the maximum permissible daily level of external estradiol entered to body through edible products recommended by EU and CAC (3.5 µg), at least in the short term, there will be no remarkable impact on the endocrine system. However, judging the long-term effects of using these products is not easy and simple at all, as cancers develop during a long period of time and has a multifactorial etiology.

Development and characterization of blends formulated with banana peel and banana pulp for the production of blends powders rich in antioxidant properties

Abstract

The food product industry is increasingly looking for foods with nutritional properties that can provide health benefits. Additionally, a challenge for the food industry is the use of all raw materials. For these reasons, banana peel that is a raw material from Banana (Musa spp.) fruit emerges as potential for new food product development. Here, we developed powder blends using a lyophilization process for the preparation of flour to potential use in cookies, bread, and pasta products. Three formulations were designed; the main difference in the formulations was the use of banana peel concentration. Our results showed that blends produced with banana peel presented physical–chemical properties considered suitable for use in food industry. Moreover, the evaluated morphological parameters reveal the properties of the powders. The blends formulated with banana peel have more antioxidant properties, showing that the banana peel may be an attractive option to generate powders with high antioxidant properties.

Preliminary study of the influence of mineral content on quality parameters of Jordanian-origin honey collected from different geographical regions

Abstract

In this work, physicochemical properties of eight honey samples harvested from different regions over Jordan were investigated. Quality parameters including free acidity, pH, conductivity, 5-hydroxymethylfurfural (5-HMT) and diastase activity were monitored for freshly harvested samples and during storage time over 24-month. The level of minerals (Na, K, Mg, Ca, Fe, Ni, Cu, Hg, Pb and As) in samples were quantified and found to be highly variable. The combined mineral content in the collected honeys was following the trend: multi-floral-Madaba (275.17 mg/kg) < multi-floral-Southern Shouna (600.83 mg/kg) < Centaurea iberica-Irbid (654.42 mg/kg) < Ziziphus Spina Christi-Al-Ghour (747.14 mg/kg) < Urginea maritima-Petra (752.52 mg/kg) < Echinopspolyceras-Karak (830.41 mg/kg) < Eucalyptus-Al-Azraq (1117.1 mg/kg) < multi-floral-Jerash (2297.57 mg/kg). As indicated from the trend, the mineral content in multi-floral-Jerash was notably high even when compared with international values. Harmful elements such as Cu, Hg, Pb and As were not detected providing higher nutritional value for the local honey. For fresh honeys, analysis revealed that samples rich with minerals have lower moisture, higher acidity, lower pH, and lower diastase activity. After 24-month storage, samples of higher minerals manifested higher values of 5-HMF and this supported that minerals would speed up glucose conversion.

Identification of endophytic bacteria in medicinal plants and their antifungal activities against food spoilage fungi

Abstract

Endophytes are fungi or bacteria living in the intracellular parts of the plants. In this study, 12 medicinal plants were examined for the presence of endophytic bacteria. Antifungal activities of the isolates were determined against Aspergillus flavus PTCC 5006, Penicillium citrinum PTCC 5304, Aspergillus fumigatus PTCC 5006, Fusarium oxysporum MTCC 284, and Rhizopus stolonifer. In order to determine the metabolites characteristics of these isolates, catalase and proteolytic enzyme treatments were assessed. Moreover, approximate molecular weights of the antifungal substance were measured by fractionation method and the volatile compounds were determined by using GC-mass spectroscopy. Finally, 16s rRNA gene sequencing confirmed the strain of the bacteria. Twenty-one endophytic bacteria, out of a total of 82 isolates, showed antifungal activities against all five spoilage fungi. The results of the PCR assay revealed two species: Bacillus pumilus and B. safensis. Proteolytic enzyme activities and the fractionation of the supernatants proved that more than one compound was responsible for the antifungal activities. This compound could be proteins, peptides, and other low-molecular compounds, such as Butanal, 3-methyl-, Propene, 2-butene, 2-heptanone, 6-methyl-5-methylene-, and 6-oxabicyclo[3.1.0] hexane, which all were identified in the headspace of the GC-mass spectroscopy.

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