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Volume 13, Issue 2, 2024
Online ISSN: 2182-1054
Volume 13 , Issue 2, (2024)
Published: 18.10.2024.
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18.10.2017.
Original scientific paper
Cytotoxic, antioxidant and antimicrobial properties of red sweet pepper (Capsicum annuum L. var. Llanerón) extracts: In vitro study
Alcoholic and aqueous extracts were obtained from red sweet pepper (Capsicum annuum L.) by different methodologies to evaluate their cytotoxic, antioxidant and antimicrobial properties. Alcoholic extracts (MFP, MSd, SFP, SDP, SSd) from fresh red sweet pepper (FP) and dry pulp (DP) and seed (Sd) were obtained by maceration (M) and Soxhlet (S) equipment using methanol as extraction solvent; whereas aqueous extracts (LFP, LSd) were obtained by decoction followed by lyophilization (L). Human tumoral cell lines from breast (MCF-7 and SKBr3), prostate (PC3) and cervix (HeLa), and fibroblasts (as control) were used to determine the cytotoxic properties by the MTT assay. Antioxidant and antimicrobial properties were determined by DPPH and disc diffusion method, respectively. The extracts SDP and SFP showed the higher cytotoxic activity. The SDP extract had a significant (P < 0.05) in-vitro effect on HeLa (1.9 ± 1.4 µg/mL) and PC3 (< 1 µg/mL) cells with a moderated impact on fibroblasts (26.1 ± 1.2 µg/mL); whereas, SFP had a significant (p < 0.05) effect on MCF-7 cell line (2.1 ± 1.2 µg/mL) with a moderated impact on fibroblasts (25.9 ± 1.0 µg/mL). The higher antioxidant activity was found for MFP (80.3 ± 0.2%) and SFP extracts (75.5 ± 0.5%). Mild antimicrobial activity was only observed for alcoholic extracts. The results showed the potential of red sweet pepper (C. annuum L.) as a source of antioxidant and cytotoxic compounds, and suggest the need of further studies to isolate and characterize the bioactive compounds that impart those properties.
Rosa Raybaudi-Massilia, Alırica I. Suarez, Francisco Arvelo, Alexandra Zambrano, Felipe Sojo, Marıa I. Calderon-Gabaldon, Jonathan Mosqueda-Melgar
18.10.2017.
Original scientific paper
Influences of physicochemical stresses on injury and inactivation behaviour of Listeria innocua
Many minimally processed foods depend on a combination of inhibitory factors to reduce the hazard of foodborne illness. Therefore, inactivation of Listeria innocua was studied according to a 24 factorial experiment designed to draw conclusions about temperature (52.5 °C and 65.0 °C), pH (4.5 and 7.5), water activity (aw=0.95 and 0.99) and solute type (NaCl and glycerol) effects. Three different recovery media were used to assess injured cells. Survival data were fitted with a Gompertz-based model and kinetic parameters (shoulder, maximum inactivation rate – kmax, and tail) were estimated. Results showed that shoulder was affected by temperature, pH and combined effects; kmax was influenced by all factors and their combinations; and tail was affected by aw, temperature and aw/pH combination. Results demonstrated the potential occurrence of microbial cross-protection survival techniques between the various stresses, e.g. heat and osmolarity. Indeed, this work clearly established that, to avoid hazards, Listeria inactivation must be evaluated with a maximum of environmental factors that undergo alterations. Only thus, appropriate food preservation treatments can be developed and consequently, the safety of food products can be assured.
Fatima A. Miller, Barbara Ramos, Maria M. Gil, Teresa R. S. Brandao, Paula Teixeira, Cristina L. M. Silva
18.04.2017.
Original scientific paper
Optimization of microwave vacuum drying parameters for germinated lentils based on starch digestibility, antioxidant activity and total phenolic content
The aim of this study was to optimize the processing parameters of pulse mode microwave-vacuum drying of germinated green and red lentils (CDC Greenland and CDC Maxim) and investigate the changes in their total phenolic content (TPC), total antioxidant activity (TAA) and In-vitro starch digestibility (SD). The lentils were germinated for 5 days and dried by a pulse mode microwavevacuum method, using 2 s to 8 s out of 10 s pulsed mode at 2000W microwave power and varying the vacuum pressure level between 15 and 45 kPa. In-vitro starch digestibility increased significantly with increased microwave power level. The TPC and TAA appeared to vary distinctively in the two varieties of selected lentils. Vacuum pressure levels did not significantly (p>0.05) affect any responses. Green lentils could be dried at 8 s microwave power and 45 kPa vacuum pressure and red lentils could be dried at 5.5 s microwave power and 42.19 kPa vacuum pressure. The microwave-vacuum drying showed great potential for the drying of germinated lentils.
Robbarts Nongmaithem, Venkatesh Meda
18.04.2017.
Original scientific paper
Rheological properties of traditional balsamic vinegar: New insights and markers for objective and perceived quality
The molecular structure of Traditional Balsamic Vinegar (TBV) undergoes shear-induced and timedependent jamming transitions due to the high solute concentration and self-assembling phenomena of high molecular size melanoidins with very-long relaxation times (12 years at least or more than 25). The purpose of this work was to perform a descriptive and quantitative evaluation of relationships between rheological properties, vinegar composition, and perceptual assessment of sensory properties according to the official sensory procedure. With this aim, vinegars having quality traits matching legal requirements for the PDO designation were analyzed for their reducing sugars (glucose and fructose), volatile acidity, fixed acidity, pH, Brix degree, and density as well as for their flow behaviour and dynamic viscosity over a wide range of shear rates. Results showed that flow behaviour of TBV was affected by jamming properties over wide-scale ranges of shear rate producing flow instability below a shear rate of 60 s−1 . Homogeneous, continuous flow was found at medium-high shear rates with thickening and/or thinning traits. A common onset for the structure scaling was mathematically estimated to occur close to when the density was 1.32 gmL−1 . Comparative analysis of rheological, compositional and sensory properties suggested that the colloidal jamming of the vinegar melanoidins dominated the total olfactive and gustative stimuli, and determined the classification of the vinegars that had a higher dynamic viscosity but more homogeneous flow as being of the highest commercial quality category. A robust statistical model was proposed encoding for the top-down decision-making process for quality assignment according to the official sensory procedure, using composition and flow properties as predictor variables.
Pasquale Falcone, Elisa Sabatinelli, Federico Lemmetti, Paolo Giudici
18.10.2017.
Original scientific paper
Drying characteristics of zucchini and empirical modeling of its drying process
The aim of the study was to dry zucchini (Cucurbita pepo) by two different methods (convective hot-air (CHD) and microwave-assisted drying (MWD)). The effect of air temperature (60, 70 and 80°C), microwave (MW) power (180, 360, 540 W) and sample thickness (5 and 10 mm) on some drying characteristics of zucchini were investigated. Thirteen mathematical models available in the literature were fitted to the experimental moisture ratio data. The coefficients of the models were determined by non-linear regression analysis. It was determined that the model that fits the moisture ratio data the best varies at different drying conditions. Increasing drying temperature and MW power and reducing sample thickness improved the drying rate and drying time. Drying in microwave has reduced the drying time by 52-64% for zucchini. It was found that the effective moisture diffusivities increased with increasing temperature and MW power. MWD samples had better rehydration ratios compared to ones dried only in tray drier for 5 mm thickness.
Naciye Kutlu, Asli Isci
18.04.2017.
Original scientific paper
In vitro investigation of antioxidant activities of Launea taraxacifolia and Crassocephalum rubens
Launea taraxacifolia and Crassocephalum rubens are among many wild, underutilized and under cultivated vegetables in Nigeria that are at risk of extinction. Total flavonoid contents (TFC), total phenolic contents (TPC), and antioxidant activities of different concentrations (1-5 mg ml−1 ) were evaluated; using in vitro assays to assess the scavenging properties of 2, 2-diphenyl-1-picryl hydrazyl (DPPHRSP), nitric oxide (NORSP) and hydroxyl (OHRSP). Phenolic profiles of the alcoholic extracts were characterized using high-performance liquid chromatography techniques. The results revealed higher TFC (mg/100g RE) in aqueous (6.06±0.02-78.79±0.01) than alcohol extracts (with methanol 0.93±0.01—12.73±0.04, and with ethanol -0.85±0.01–7.70±0.03). In a similar trend, OHRSP (%) was higher in aqueous extracts (40.83±0.10–91.74±0.19) than alcoholic extracts (with methanol - 11.67±0.3–30.83±0.06; and with ethanol -14.42±0.06-40.27±0.05). TPC (mg/100g GAE) which was higher in alcoholic extracts (with methanol -21.48±0.01–133.20±0.16 and with ethanol -9.45±0.01– 59.73±0.02) than aqueous extracts (14.83±0.01–52.64±0.03) was in agreement with the trend observed for NORSP (28.24±0.05-151.76±0.08 for methanolic extracts, 21.99±0.13–49.93±0.04 for ethanolic extracts and 38.47±0.11–86.15±0.05 for aqueous extracts). DPPHRSP was also higher in alcoholic extracts (methanolic -22.81±0.01-48.41±0.05 and ethanolic–14.53±0.01-62.68±0.07) than aqueous extracts (13.66±0.13–42.86±0.03). TFC, TPC and antioxidant activities showed concentration dependent increase and strong positive correlation with TFC (r= 0.926 – 0.997and r= 0.432 – 1.000) and TPC (r= 0.825 – 0.999 and r= 0.473 - 0.994) for L. taraxacifolia and C. rubens respectively. Caffeic acid, chlorogenic acid, ellagic acid, quercetin and kaempferol were identified as major phenolic components in the extracts. The vegetables have high antioxidant potential for promoting good health; which could be attributed to the identified phytochemicals in them.
Funmilayo B. Borokini, Lajide Labunmi
18.04.2017.
Original scientific paper
Effect of inulin on dough and biscuit quality produced from different flours
One of the methods of improving the nutritional profile of baked-goods is the incorporation of dietary fibre (DF) to the formulation. However, DF retains more water than wheat flour which, affects dough rheological properties and thus the final product quality. Flour is the main ingredient in biscuits and contributes to the baked texture and shape of biscuits. There are large differences in quality among the flours from wheat cultivars and among non-wheat flours used for biscuit production. In previous works, different dietary fibres were tested and inulin was found to have a positive quality effect on biscuits made from an all-purpose wheat flour without the need of introducing significant changes in dough properties. To know whether these results are extended to different types of flours that can be used for biscuit production, this paper aimed to analyse the effects of different levels of inulin incorporation on dough and biscuits quality made from three different wheat flours and one triticale flour. Chemical and physic-chemical characterization of the flour samples was performed and compared (moisture, ashes, gluten, solvent retention capacity (SRC) and protein content). Inulin was incorporated to biscuits formulation in two levels: 6 and 12% (wheat replacement). Dough and biscuits quality was measured by spread rate during baking and biscuit factor, texture and surface colour. Inulin incorporation increased dough spreading and biscuit factor and decreased biscuit hardness. The enhancing effect of inulin was observed in all flour. The results confirmed the effect of inulin on biscuits obtained with all flour assayed, despite the differences in flour quality that was tested.
Maria S. Blanco Canalis, Alberto E. Leon, Pablo D. Ribotta
01.12.2016.
Professional paper
Influences of physicochemical stresses on injury and inactivation behaviour of Listeria innocua
Fátima A. Miller, Bárbara Ramos, Maria M. Gil, Teresa R.S. Brandão, Paula Teixeira, Cristina L.M. Silva
18.10.2016.
Original scientific paper
Antioxidant activities and inhibitory effects of free and bound polyphenols from date (Phoenix dactylifera L.) seeds on starch digestive enzymes
Date (Phoenix dactylifera L.) seeds have gained interest as a valuable by-product of the date fruit industry and have been identified as a rich source of functional and bioactive ingredients. In this study, date seeds from five varieties (Medjool, Deglet Nour, Barhee, Bou Sthammi and Dayrie) cultivated in Australia were analysed for their total phenolic and flavonoid contents, ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and in-vitro inhibition against α-amylase and α-glucosidase. The date seed powders (DSP) were extracted with acetone-methanol-water (2:2:1, v:v:v) to obtain free polyphenols. The bound polyphenols were extracted from the residual solids with butanolHCl (97.5:2.5; v/v) treatment at 100 °C. The greatest quantities of total phenols (4166±227 mg Gallic Acid Equivalents 100g−1 DSP), total flavonoids (52.1±9.6 mg Quercetin Equivalents 100g−1 DSP), FRAP (1589±47 µmol Iron (II) Equivalents g−1 DSP) and TEAC (45.2±1.4 µmol Trolox Equivalents g −1 DSP) were detected in seeds from Deglet Nour variety. Both free and bound polyphenol fractions showed significant (p<0.05) inhibition against rat intestinal α-glucosidase with little or no inhibition against pancreatic α-amylase. Bound polyphenols showed stronger α-glucosidase inhibition compared with free polyphenols. The IC50 for α-glucosidase were reported as mg GAE mL−1 ranged from 0.39±0.02 (Deglet Nour ) to 0.68±0.02 (Medjool) for bound polyphenols, and from 0.907±0.08 (Medjool) to 1.75±0.15 (Barhee-khalal) for free polyphenols. Bound polyphenol fraction, with strong α-glucosidase inhibition and weak α-amylase inhibition, was suggested as a significant source of functional food ingredients with anti-hyperglycaemic properties.
Sameera Sirisena, Ken Ng, Said Ajlouni
18.04.2016.
Original scientific paper
Towards the development of a common starter culture for fufu and usi (edible starch): Screening for potential starters
Fermented cassava products like fufu and usi are important staple foods in many African homes. Natural fermentation time is usually long resulting in slower acidification and inconsistent nutritional composition of products which could be overcome with the use of starter culture. However, most available starters are used for single food fermentation and are uneconomical. This necessitates the development of a starter culture for multiple related food products to reduce cost. Hence, this study aimed at screening for potential starters in the development of a common starter culture for fufu and usi. Fresh, peeled, chipped and grated cassava tubers were spontaneously fermented and lactic acid bacteria were isolated from the fermenting mash at 24 hour intervals. Ninety eight (98) isolates were randomly picked. Lactobacillus plantarum had highest occurrence (50.0%) in both fermentations. All selected isolates did not hydrolyze starch, but produced linamarase and pectinase. Fermenting pH ranged between 6.50 and 3.58 during 72 hours fermentation. Lactic acid concentration ranged from
1.10 g/L to 1.78 g/L at 24 hours, 1.22 g/L to 2.45 g/L at 48 hours and 0.57 g/L to 2.55 g/l at 72 hours. The highest hydrogen peroxide concentration produced was 629 µg/L at 24 hours while the least was 136 µg/L at 72 hours. 1.08 g/L of diacetyl was the least concentration produced at 24 hours while the highest was 2.86 g/L at 48 hours. Five potential starters were identified as Lactobacillus pentosus F2A, L. plantarum subsp. argentolarensis F2B, L. plantarum F2C, L. plantarum U2A and L. paraplantarum U2C.
Kubrat Oyinlola, Anthony A. Onilude, Oluwaseun E. Garuba