Pigment identification,nutritional composition,bioactivity, and in vitro cancer cell cytotoxicity of Rivina humilis L. berries,potential source of betalains

Ripened berries of Rivina humilis L. (pigeon berry) were investigated for pigment and nutritional composition, in vitro bioactivities, and cancer cell cytotoxicity of its extracts. Ten betalain pigments (total content–0.35 g/100 g fresh weight, and 1.7 g/100 g dry weight) with high level of betaxanthins were characterised. Carbohydrates (6.2 g), proteins (1.1 g), lipids (0.7 g), phenols (105.7 mg gallic acid equivalent), niacin (5.3 mg), and total tocopherols (0.77 mg) in 100 g fresh weight were observed. Antioxidant bioactivity of MeOH extract (maximum at 100 μg/mL) against OH and β-carotene oxidation was studied. The extract (1000 μg/mL) effectively protected kidney lipid peroxidation compared to butylated hydroxy anisole. Betalains rich extract, and purified betacyanins and betaxanthins revealed EC₅₀ against DPPH (51.0, 0.29, 0.11 μg/mL), and reducing power (39.3, 2.79, and 1.34 μg/mL) which was higher than that of gallic acid and ascorbic acid. In vitro cancer cell cytotoxicity was assessed through MTT assay on HepG2 cells after exposing to betalains rich extract, betacyanins and betaxanthins for 24 h; only betaxanthins exhibited cytotoxicity (EC₅₀ 12.0 μg/mL). After 48 h of exposure, betacyanins and betaxanthins showed elevated cytotoxicity.     

Optimization of culture parameters of selenium-enriched yeast (Saccharomyces cerevisiae) by response surface methodology (RSM)

Effect of culture conditions (temperature, initial pH value and volume) on the bioaccumulation of selenium (Se) in yeast (Saccharomyces cerevisiae) were investigated by response surface methodology (RSM) in this paper. The combined effects of culture conditions on Se yield were studied using a three-level three-factor Box-Behnken design. Fermentation was carried out at different temperature (24-32 °C), initial pH value (4-7) and volume (40-100 mL). The results showed that the optimum conditions for Se enrichment of yeast were found at temperature 27.4 °C, initial pH value 5.8 and volume 89.4 mL. Total Se yield was significantly affected by culture temperature (P < 0.05), initial pH value (P < 0.01) and volume (P < 0.01).Using a culture medium supplemented with 15 μg/mL sodium selenite (Na₂SeO₃) added at 9 h after inoculation which is the logarithmic growth phase, the maximum biomass and total Se yield in yeast could reach 9.23 g/L and 5.90 mg/L, respectively, which were significantly higher (P < 0.05) than that of the control (8.82 g/L and 4.31 mg/L)     

Betacyanins in dragon fruit peels: the kinetic models of their degradation under different treatment conditions

In this study, after purification, the content of betacyanins in dragon fruit peels was 9.22 mg g⁻¹ dry sample. The stability of betacyanins under the effect of different concentration of metal cation (K⁺, Na⁺, Cu²⁺, Fe²⁺, Fe³⁺, Mg²⁺, Al³⁺) solutions and sugars (glucose, sucrose, fructose, maltose and lactose) solutions was observed. The results showed that 10% lactose and 0.08 mol L⁻¹ potassium chloride solution increased the stability of betacyanins and could be used as stabiliser agents. The degradation reaction under different temperatures (20, 30, 40, 50, 60, 70, 80 °C), pH (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0) and light conditions (light and dark) of mixed solution (betacyanins and stabiliser), including aqueous pigments solution (APS), lactose pigments solution (LPS) and potassium chloride pigments solution (PCPS), accorded with the first-order reaction kinetics. The t_1/2 values (the hours needed for 50.0% degradation of betacyanins) of LPS even up to 330.0 h at 20 °C and dark condition.     

Carotenoid pigment loss of freeze-dried plant samples under different storage conditions

Enzyme extracted carotenoid pigments from orange peel, sweet potato and carrot samples were freeze-dried and stored at 25°C light, 25°C dark, 4°C and 40°C. Color losses of freeze-dried pigments under these storage conditions were compared with the non-dried samples. For the freeze-dried samples, the highest pigment loss was in carrot pigments stored at 40°C (98.1 g/100 g) while the lowest loss was in sweet potato pigments stored in 4°C (11.3 g/100 g) during 45 days of storage. For all three samples, pigment loss was minimum at 4°C and maximum at 40°C as expected. Storage under light did not have significant effect on the carotenoid loss compared with the samples stored at dark. Freeze-drying lowered the pigment loss for all samples under all storage conditions.     

Impact of inulin and okara on Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 viability in a fermented soy product and probiotic survival under in vitro simulated gastrointestinal conditions

The effect of inulin and/or okara flour on Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 viability in a fermented soy product (FSP) and on probiotic survival under in vitro simulated gastrointestinal conditions were investigated throughout 28 days of storage at 4 °C. Employing a 2² design, four FSP trials were produced from soymilk fermented with ABT-4 culture (La-5, Bb-12, and Streptococcus thermophilus): FSP (control); FSP-I (with inulin, 3 g/100 mL of soymilk); FSP-O (with okara, 5 g/100 mL); FSP-IO (with inulin + okara, ratio 3:5 g/100 mL). Probiotic viabilities ranged from 8 to 9 log cfu/g during the 28 days of storage, and inulin and/or okara flour did not affect the viability of La-5 and Bb-12. Bb-12 resistance to the artificial gastrointestinal juices was higher than for La-5, since the Bb-12 and La-5 populations decreased approximately 0.6 log cfu/g and 3.8 log cfu/g, respectively, throughout storage period. Even though the protective effect of inulin and/or okara flour on probiotic microorganisms was not significant, when compared to a fresh culture, the FSP matrix improved Bb-12 survival on day 1 of storage and may be considered a good vehicle for Bb-12 and could play an important role in probiotic protection against gastrointestinal juices.     

Colour changes of fillets of rainbow trout (Oncorhynchus mykiss W.) fed astaxanthin or canthaxanthin during storage under controlled or modified atmosphere

Rainbow trout were fed diets containing two levels of lipids (9 g/100 g and 24 g/100 g) associated with two keto-carotenoid pigments (80 mg of astaxanthin or of canthaxanthin/kg of diet) for 4 months. After slaughter colour stability of fillets was studied during a 4-week storage at +4 °C under controlled (CA) and modified (MA) atmospheres under 100% air, 60:40 N₂-CO₂ mix and 60:40 air-CO₂ mix. Fillets from fish fed high fat level diets showed higher chroma and higher a^* and b^* colour parameters than those from fish fed low fat level diets. Storage time increased lightness and hue angle in CA but only lightness under MA. After storage at +4 °C lightness of fish fillets stored under MA were lower (P<0.05) than those stored under CA. Carotenoid source resulted in differences in chroma and hue angle of fish fillet stored under CA and MA. Dietary lipid levels resulted in differences in chroma under CA. Under CA the lower (P<0.05) differences between stored-initial values was for N₂-CO₂ and the higher (P<0.05) for air. Under MA, air-CO₂ and N₂-CO₂ gave similar results for L^*, C^* and H(°)_ab. Our experiment demonstrated that colour parameters of fish fillets reacted differently according to gas mixture and storage time.     

Study of spray drying of the Aloe vera mucilage (Aloe vera barbadensis Miller) as a function of its rheological properties

Spray Drying (SD) was used to obtain Aloe vera powder from fresh plants. The powder was reconstituted in an aqueous medium and its rheological properties, particle size distribution (PSD), thermal properties (differential scanning calorimetry, DSC), and morphology (scanning electron microscopy, SEM) were evaluated in order to find an alternative to natural gum to be used in the food industry. Rheological measurements were conducted at 25 °C in aqueous concentrations of 3 g/100 mL and 6 g/100 mL. A 2³ factorial design was used with three central points to evaluate yield, efficiency and the rheological properties of reconstituted powders, results were compared with a liophilized (FD) sample of A. vera mucilage. Experimental results showed that the shear viscosity decreased with the increase of the inlet air temperature and the speed of atomization, and it increased with increasing feed flow in SD. Additionally, most powders obtained in all treatments have an average particle diameter of ∼10 μm with a modal distribution (PSD). The best conditions of SD in order to obtain a good thickening agent were: 150 °C inlet temperature, 1.5 L/h feed rate and atomization speed of 275,000 rpm, and with rheological properties very close to those of the FD sample.     

Addition of ice-nucleation active bacteria: Pseudomonas syringae pv. panici on freezing of solid model food

Ice-nucleation active bacteria (INAB), Pseudomonas syringae pv. panici, were cultured at 26 °C in a nutrient broth and harvested at late log phase. The ice-nucleation activity unit per unit volume of the bacterial culture measured by the droplet-freezing assay developed by Vali was 3.29 × 10⁴ INA/mL. A differential scanning calorimetry (DSC) analysis of 77 g/100 g Tylose samples showed that the addition of bacteria had no obvious effect on the glass transition temperature and heat of fusion of the samples. Freezing operations carried out at −20 °C showed that the addition of INAB produced no obvious change in the freezing time. The scanning electronic microscope (SEM) observation of microstructure of the model food indicated that the mean ice crystal size was reduced from 25.7 μm to approximately 15 μm by the addition of INAB.     

Characterisation and stability evaluation of bixin nanocapsules

The aim of this study was to produce bixin nanocapsules by the interfacial deposition of preformed poly-?-caprolactone (PCL). PCL (250 mg), capric/caprylic triglyceride (400 μL), sorbitan monostearate (95 mg) and bixin were dissolved in a mixture of acetone (60 mL) and ethanol (7.5 mL) under stirring (40 °C). This organic solution was added to the aqueous solution (130 mL) containing Tween 80 (195 mg). The size distributions in the formulations with bixin concentration from 11 to 100 μg/mL were evaluated periodically during 3 weeks of storage at ambient temperature. The optimal formulation (bixin concentration of 16.92 ± 0.16 μg/mL) was characterised in terms of particle size distribution, zeta potential, bixin content and encapsulation efficiency, and showed a volume-weighted mean diameter (D_4,3) of 195 ± 27 nm, around 100% of encapsulation efficiency and the nanocapsules were considered physically stable during 119 days of storage at ambient temperature.     

Evaluation of chitosan nanoparticles as a glazing material for cryogenically frozen shrimp

The potential of chitosan (CH) combined with sodium tripolyphosphate (TPP) nanoparticles as a glazing material for shrimp was investigated. Two CH–TPP nanoparticles glazing solutions were prepared: (1). A solution containing CH–TPP nanoparticles with 0.25 (g/100 mL) CH and 0.083 (g/100 mL) TPP (25CH–TPP) and (2). A solution containing CH–TPP nanoparticles with 0.5 (g/100 mL) CH and 0.167 (g/100 mL) TPP (50CH–TPP). Frozen shrimp samples were glazed with 25CH–TPP, 50CH–TPP, CH, TPP, acetic acid, and/or distilled water and then stored at −21 °C for 30 days. Glazed and non-glazed shrimp (NG) samples were analyzed for moisture content, glazing yield, weight loss, color, cutting force, thiobarbituric acid reactive substances (TBARS), yeasts, molds, coliforms and aerobic counts after 1, 3, 5, 20, and 30 d storage. Triplicate experiments were conducted and data statistically analyzed (α = 0.05). Glazed shrimp had higher moisture than NG after 30 d storage. Among the glazes, 25CH–TPP and 50CH–TPP were the most effective in controlling lipid oxidation and reducing aerobic counts and yeasts and molds in shrimp.     

Carotenoid and flavanone content during refrigerated storage of orange juice processed by high-pressure, pulsed electric fields and low pasteurization

The impact of different processing technologies, including non-thermal technologies, on bioactive compounds of orange juice was investigated. Freshly squeezed orange juice was treated by high pressure (HP) (400 MPa/40 °C/1 min), pulsed electric fields (PEF) (35 kV cm⁻¹/750 μs) and low pasteurization (LPT) (70 °C/30 s). The stability of main carotenoids and flavanones was studied just after treatment and during 40 days of refrigerated storage at 4 °C. Just after treatment, HP juice showed a significant increase on total carotenoid and flavanone content extracted (45.19 and 15.46%, respectively) and on vitamin A value (30.89%) with regard untreated juice, whereas no significant changes were observed for PEF and LPT juices. For all treated orange juices, flavanone content decreased significantly (around 50%) during the first 20 days of storage at 4 °C while carotenoid content showed a moderate decrease (less than 11%) that took place during the last 20 days. In general, during refrigerated storage, carotenoids and flavanones remained higher in HP juice than in LPT and PEF juices. Hence, HP and PEF technologies were as effective o even more than LPT to preserve bioactive compounds in orange juice during refrigerated storage.     

Effects of drying on the phenolics content and antioxidant activity of muscadine pomace

Three drying technologies [i.e., vacuum belt drying (VBD), hot air drying (HAD), and freeze drying (FD)] were evaluated for the processing of muscadine pomace in terms of their impact on drying time requirement, moisture content (MC), water activity (a_w), total phenolics content (TPC), and antioxidant activity (AA). Muscadine pomace discs of two thicknesses (2 and 4 mm) were dried using 16 different time-temperature combinations for VBD, 12 different time-temperature and air velocity combinations for HAD, and one treatment for FD. The TPC and AA in lyophilised samples were 583 ± 8 and 608 ± 16 μmol GAE/g d.w. and 2.21 ± 0.15 and 2.30 ± 0.17 mmol Fe²⁺ E/g d.w. for the 2 and 4 mm thick discs, respectively. The VBD treatment of 60-80-100-100 °C for 60 min (i.e., TV2) for 2 mm thick discs showed the highest TPC value, and no significant (P > 0.05) differences were observed in AA of 2 mm thick discs dried by VDB and FD. The TPC and AA for the VBD treatment of 60-80-100-100 °C for 90 min and HAD treatment of 70 °C at 0.6 m/s for 3 h for the 2 mm thick discs were not significantly (P > 0.05) different compared to freeze dried samples. For 4 mm thick samples, the TPC and AA for the VBD treatments of 60-80-100-100 °C, 60-90-120-120 °C, 70-90-110-110 °C, 80-90-100-100 °C, and 90-105-120-120 °C for 90 min as well as 70-90-110-110 °C for 60 min were not significantly (P > 0.05) different compared to those for freeze dried discs. VBD is a promising drying technology, as the resultant products possessed high TPCs and were dried in less than ¼ of the time compared with that of FD.     

Effects of packaging materials,storage conditions and variety on oxidative stability of shelled walnuts

The effects of storage temperature, oxygen permeability of packaging material and variety on oxidative stability of vacuum-packaged walnut kernels were studied over a 12 months storage period. The oxidation experiments applied to two popular walnut varieties (Yalova-1 and Yalova-3) grown in Turkey. The peroxide values and hexanal contents of walnut samples significantly increased (p < 0.01) during storage at 30 °C. The highest hexanal content (4464.5–6406.9 μg/kg) were observed in Yalova-3 variety stored at 30 °C for 12 months in Polyamide/Polyethylene film pouches (oxygen permeability: 63.4 ± 0.4 mL/m²/24 h (23 °C)) with 90 μm total thickness. The effect of storage temperature and variety on lipid oxidation was found to be higher than the effect of oxygen permeability of the packaging material. It was concluded that for vacuum-packed walnut kernels in PA/PE film pouches having 63.4 ± 0.4 mL/m²/24 h (23 °C) oxygen permeability, 20 °C is sufficient to protect against oxidation for 12 months.     

Renal excretion of antioxidative constituents from red beet in humans

The aim of the present study was to assess the renal excretion of red beet juice (RBJ) antioxidants in six healthy humans. After a single oral dose of RBJ. The pharmacokinetic parameters obtained from urine were compared to those obtained after ingestion of water on an intra-individual basis. Urine was collected in intervals up to 24 h post-intake. After RBJ ingestion, the betacyanins betanin and isobetanin were excreted in the volunteers’ urine (0.28% of the administered dose) and unambiguously identified by HPLC–ESI-MS/MS. Compared to the ingestion of water, RBJ consumption resulted in a significantly increased urinary excretion of total phenolics (51.1% of the administered phenolics) and other antioxidant compounds (43.9% of the administered compounds) within 24 h.     

Selenium enriched green tea increase stability of Lactobacillus casei and Lactobacillus plantarum in chitosan coated alginate microcapsules during exposure to simulated gastrointestinal and refrigerated conditions

The effects of selenium enriched green tea (SGT; 85.8–96 mg/kg) in different concentrations of 1 g and 2 g/100 mL, on the in vitro exposure to simulated gastrointestinal juice and refrigerated storage of encapsulated Lactobacillus casei and Lactobacillus plantarum were investigated in chitosan coated alginate beads. The encapsulation yield of viable cells in chitosan coated alginate beads with and without SGT was not significantly different (P < 0.05). These results together with the study about the survival of probiotic bacteria in microspheres with SGT during storage at 4 °C, demonstrated significantly higher number (P < 0.05) of survival bacteria in microcapsules with SGT 2 g/100 mL. Microencapsulated L. casei and L. plantarum with SGT 1 g and 2 g/100 mL were resistant to simulated gastric conditions (pH 2.0, 2 h) and bile solution (3 g/100 mL, 2 h) resulting in significantly (P < 0.05) improved survival when compared with microencapsulation without SGT addition.     

Production of new antioxidant compound from mycosporine-like amino acid,porphyra-334 by heat treatment

In this study, we evaluated the antioxidant activity (diphenylpicrylhydrazyl (DPPH)-radical scavenging activity) of the low-molecular weight fraction of water-soluble Susabinori (Porphyra yezoensis) extract (LMF). DPPH-radical scavenging activity of LMF (65.5 μmol-Trolox eq/ml) was enhanced at temperatures over 100 °C (1.4, 2.0 and 2.4 times higher at 100, 110 and 120 °C, respectively). As a result of HPLC separations, a newly produced peak was observed in heat treated LMF, while a marked decrease of another peak was found after heat treatment of LMF. The decreased peak was identified as porphyra-334, which is a typical mycosporine-like amino acid, by ESI/MSⁿ analysis (protonated molecule [M + H]⁺ at m/z 347.1 and its fragment ion 303.1). The newly produced compound with [M + H]⁺ at m/z 329.1 was found to be a dehydrated compound of porhyra-334. The compound exhibited an extremely high-IC₅₀ value of 10.1 μg/ml in DPPH-radical scavenging activity, compared to porphyra-334 (>1000 μg/ml).     

Effects of supercritical CO2 fluid parameters on chemical composition and yield of carotenoids extracted from pumpkin

Pumpkin is a traditional food that is grown extensively worldwide and is believed to be beneficial to human health due to its high contents of carotenoids. The carotenoids in pumpkin were extracted by organic solvents and by supercritical carbon dioxide (SC-CO₂), and then they were identified, quantified, and compared. β-carotene (31 to 40 g per 100 g of total carotenoids) was the predominate carotenoid in pumpkin. Lutein and lycopene contents were much higher in SC-CO₂ extracts than those in organic solvent extract. Cis-β-carotene increased by more than two times in the SC-CO₂ extracts, even at a relatively low temperature of 40 °C, over those in the solvent extracts, indicating both enhanced solubility and isomerization from trans- to cis-β-carotene. The influences of modifier (10 mL/100 mL), temperature (40-70 °C), and pressure (25-35 MPa) of SC-CO₂ extraction on the change of carotenoid yields were also investigated. The highest yield (109.6 μg/g) was obtained at 70 °C and 35 MPa, with a 73.7% recovery. Selective extraction could be achieved by adjusting the temperature and pressure. Higher proportions of all-trans-β-carotene extracts were achieved at 40 °C under both 25 MPa and 35 MPa conditions. In order to extract more cis-isomers, a higher temperature of 70 °C was preferred.     

Selenium analysis of selected Egyptian foods and estimated daily intakes among a population group

The selenium (Se) content of 67 local foods had been determined using electrothermal (ETAAS) and hydride generation (HGAAS) atomic absorption spectrometry. The richest sources of Se were chicken (323±35 μg kg⁻¹); eggs (166±19.4 μg kg⁻¹) and fish (306±5.2 μg kg⁻¹). Vegetables and fruits contained trace amounts of Se (1–33 μg kg⁻¹). Wide variations in Se content were reported between various bread types and values ranged from 14 (home-made bread) to 152 (flattened bread) μg kg⁻¹, respectively. The estimated adult Se intake was 49 μg kg⁻¹; bread being the major contributor (63.6%). ©     

Performance of whey protein hydrolysate–maltodextrin conjugates as emulsifiers in model infant formula emulsions

Model infant formula emulsions containing 15.5, 35.0 and 70.0 g L⁻¹ protein, soybean oil and maltodextrin (MD), respectively, were prepared. Emulsions were stabilised by whey protein hydrolysate (WPH) + CITREM (9 g L⁻¹), WPH + lecithin (9 g L⁻¹) or WPH conjugated with MD (WPH–MD). All emulsions had mono-modal oil droplet size distributions post-homogenisation with mean oil droplet diameters (D_4,3) of <1.0 μm. No changes in the D_4,3 were observed after heat treatment (95 °C, 15 min) of the emulsions. Accelerated storage (40 °C, 10 d) of unheated emulsions resulted in an increase in D_4,3 for CITREM (2.86 μm) and lecithin (5.36 μm) containing emulsions. Heated emulsions displayed better stability to accelerated storage with no increase in D_4,3 for CITREM and an increase in D_4,3 for lecithin (2.71 μm) containing emulsions. No increase in D_4,3 over storage was observed for unheated or heated WPH–MD emulsion, indicating its superior stability.     

Fate of Listeria monocytogenes during freezing,thawing and home storage of frankfurters

Little information is available regarding the fate of Listeria monocytogenes during freezing, thawing and home storage of frankfurters even though recent surveys show that consumers regularly store unopened packages in home freezers. This study examined the effects of antimicrobials, refrigerated storage, freezing, thawing method, and post-thawing storage (7 °C) on L. monocytogenes on frankfurters. Inoculated (2.1 log CFU/cm²) frankfurters formulated without (control) or with antimicrobials (1.5% potassium lactate plus 0.1% sodium diacetate) were vacuum-packaged, stored at 4 °C for 6 or 30 d and then frozen (−15 °C) for 10, 30, or 50 d. Packages were thawed under refrigeration (7 °C, 24 h), on a countertop (23 ± 2 °C, 8 h), or in a microwave oven (2450 MHz, 1100 watts, 220 s followed by 120 s holding), and then stored aerobically (7 °C) for 14 d. Bacterial populations were enumerated on PALCAM agar and tryptic soy agar plus 0.6% yeast extract. Antimicrobials completely inhibited (p < 0.05) growth of L. monocytogenes at 4 °C for 30 d under vacuum-packaged conditions, and during post-thawing aerobic storage at 7 °C for 14 d. Different intervals between inoculation and freezing (6 or 30 d) resulted in different pathogen levels on control frankfurters (2.1 or 3.9 log CFU/cm², respectively), while freezing reduced counts by <1.0 log CFU/cm². Thawing treatments had little effect on L. monocytogenes populations (<0.5 log CFU/cm²), and post-thawing fate of L. monocytogenes was not influenced by freezing or by thawing method. Pathogen counts on control samples increased by 1.5 log CFU/cm² at d-7 of aerobic storage, and reached 5.6 log CFU/cm² at d-14. As indicated by these results, consumers should freeze frankfurters immediately after purchase, and discard frankfurters formulated without antimicrobials within 3 d of thawing and/or opening.