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Abstract

The aim of the present study was to find the best extraction parameters to obtain the highest amounts of polyphenols and antioxidants from the walnut. Walnut kernels from ‘Alsószentiváni 117’ cultivar were used for extraction. The extraction methods were as the follows:

Method 1: shaking water-bath at 50 °C for 30 min.

Method 2: shaking water-bath at 50 °C for 30 min, then storing at 5 °C for 20 h.

Method 3: shaking water-bath at 40 °C for 30 min.

Method 4: shaking water-bath at 40 °C for 30 min, then storing at 5 °C for 20 h.

According to our results Method 1 showed the highest FRAP value (34.43 mg AAE g−1), the DPPH value (52,94%) and the highest HPLC peaks for chlorogenic acid, epicatechin and rutin were also seen in extracts obtained using Method 1. TPC values of Method 3 were 26.06 mg GAE g−1 for Method 1 it was 25.65 mg GAE g−1. The results of color values, L* and ΔE* were similar in all extracts as well. In our experiments extraction Method 1 proved to be better than others.

Open access
Progress in Agricultural Engineering Sciences
Authors:
Zsuzsanna Horváth-Mezőfi
,
Emese Bátor
,
Gergő Szabó
,
Mónika Göb
,
Zoltán Sasvár
,
Lien Le Phuong Nguyen
,
Koppány Majzinger
,
Karina Ilona Hidas
,
Anna Visy
,
Géza Hitka
, and
Tamás Zsom

Abstract

Ethylene has key roles in triggering and speeding up ripening processes, which in tomatoes take the form of various qualitative changes. Tomatoes, just like all climacteric fruits, need a continuous ethylene exposure to accelerate ripening. Therefore, it is possible to use ripening regulators preventing ethylene binding. According to some studies, chlorophyll fluorescence measurements can be used at least as efficiently as tristimulus colorimetry classifying tomatoes based on maturity. Measurements were carried out by treating fresh tomatoes with 1-MCP (1-methylcyclopropene) at six different stages of ripening and studying the changes in chlorophyll content related quality characteristics (e.g. surface colour, chlorophyll fluorescence) during postharvest storage (two-week refrigerated storage at 15 °C followed by a two-week shelf life). According to our results, chlorophyll content and photosynthetic activity of the treated samples decreased much less than those of untreated ones. Additionally, anti-ripening treatment proved to be more effective on tomatoes at an earlier stage of ripening.

Open access

Abstract

In this work, the simulated adulteration of coconut drink by dilution with water was investigated using laser-light backscattering (LLB) imaging. The laser vision system consisted of six low power laser modules, emitting 1 mm diameter beams at wavelengths of 532, 635, 780, 808, 850 and 1,064 nm. The backscattering images were acquired by a grey scale camera with 12 bit resolution. Eight parameters were extracted to describe the backscattering profile. The methods of linear discriminant analysis (LDA) and partial least squares (PLS) regression were performed on LLB parameters for classifying and predicting dilution level of adulterated coconut drink samples. Based on the results, LLB signals responded sensitively to adulteration. LDA results showed that adulterated samples were correctly recognized with accuracies between 60 and 100%. PLS models were able to estimate the adulteration level of samples with coefficients of determination of 0.57–0.97 in validation. This result demonstrated the potential of laser-light backscattering imaging as a rapid and non-destructive optical technique for evaluation of coconut drink adulteration.

Open access

Talajnedvesség-tartalom mérése földradarral (GPR) és mezőgazdasági alkalmazhatóságának lehetőségei

Soil water content measurements with ground penetrating radar (GPR) and its application possibilities in the agriculture

Agrokémia és Talajtan
Authors:
András Herceg
and
Csaba Tóth

Measurement of soil water content is complicated due to the soil heterogeneity and environmental variability. No single efficient method has been developed to map the different soil moisture zones at great depth at the field scale without disturbing the soil structure and paths of the waterflow.

Partially or completely non-destructive measurement of soil moisture is provided by ground-penetrating radar (GPR), which offers high resolution and significant penetration depth for medium-scale soil moisture measurements, bridging the methodological gap between small-scale point-based and large-scale remote sensing techniques. In addition, this technique can be used with better time efficiency compared to other destructive or non-destructive procedures.

GPR has been used for soil water content estimation including measuring soil water content profile, identifying specific soil water depths or soil water variation under irrigation conditions.

Despite the high potential of GPR for hydrological investigations, it is important to realize that no single geophysical method is able to perform optimally under all conditions. For example, GPR is mostly restricted to areas with relatively low electrical conductivity (low attenuation of the electromagnetic wave). In addition, some of the GPR interpretation methods require the presence of well identifiable and continuous GPR reflections, which requires sufficient and spatially continuous subsurface contrast in dielectric permittivity.

Soil moisture (considering its flow) is a key variable in the fields of agriculture. It is the essential requirement for plants to grow. Consequently, soil moisture is important for irrigation management particularly in semiarid and arid regions.

In this paper, the literature of the principles of GPR measurements and utilization possibilities is summarized with the emphasis on the agricultural sector. GPR can be a beneficial measuring device that can help in mapping soil moisture distribution, taking into account infiltration, but also water loss caused by evaporation and plant water absorption. Consequently, it can be used in agriculture, due to its precision at high central frequency values, even (fine)root characteristics of the plants, essentially the xylem-water relationship can also be determined (xylem transports water and water-soluble minerals and supply water used during photosynthesis). In addition, GPR can provide valuable information regarding natural stratification and soil compaction. The data interpretation of GPR measurements, in addition to soil compaction causing a decrease in the moisture of soils (as three-phase systems), can in principle be extended to other aspects of agrotechnology, such as soil contamination studying. However, it has not been sufficiently explored, as no recent literature can be found on this subject.

Soil radar can be a useful part of “Smart farming”, which can help in the selection of soil moisture measuring sensors placed in the soil as part of it. Especially when associated with the recently released new simultaneous multi-offset and multi-channel (SiMoc) GPR system, which enables fast soil profile mapping with seven receivers, but at the speed of a traditional single-channel GPR.

If complete non-destruction is the goal, air-coupled GPRs mounted on a drone can provide an opportunity. It should be noted, however, that due to the significant signal attenuation (wave scattering) occurring at the soil-air interface, only a small penetration depth can be achieved.

Open access

Abstract

In order to improve the thermal performance of heat exchangers and air collectors, we insert various forms of artificial roughness, known as ribs, into the useful duct. These ribs promote the creation of turbulent flows and enhance heat transfer by conduction, convection and radiation.

However, the introduction of these ribs leads to an increase in pressure drop, requiring higher mechanical power to pump the heat transfer fluid. This experimental study focuses on estimating, using empirical approaches, the pressure losses induced by rectangular ribs with an inclined top. The ribs are made from 0.4 mm galvanized sheet steel.

An experimental set-up was designed to measure the head losses generated by the ribs, from the point of entry to the point of exit from the useful duct. Using the dimensional analysis method, correlations were established to evaluate head losses as a function of flow regime and rib geometry and configuration (including different geometries for rib arrangement over the configuration area).

Open access

Abstract

Soluble dietary fibre (SDF) is well recognised for its remarkable effectiveness in promoting human health. This study utilised response surface methodology to evaluate the optimal conditions required to extract SDF (U-SDF) from Lentinula edodes via the ultrasonic-assisted hot-water method, and evaluated the hypolipidemic effects and anti-inflammatory effects of U-SDF. The optimal extraction conditions for U-SDF were ultrasonic power of 182 W, extraction time of 2 h, extraction temperature of 81 °C, and solid-liquid ratio of 1:24 (g mL−1). Under these conditions, the extraction rate of U-SDF reached 8.08%. U-SDF treatment significantly improved liver and kidney indices in diabetic mice, markedly reduced the levels of plasma triglycerides (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and significantly increased the level of high-density lipoprotein-cholesterol (HDL-C) in a dose-dependent manner. U-SDF also improved adipose tissue injury in diabetic mice, significantly decreased the levels of cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α), and alleviated inflammation of the abdominal aorta. In conclusion, U-SDF from L. edodes is an excellent source of dietary fibres, which exhibit good hypolipidemic and anti-inflammatory activities, suggesting potential applications as a functional additive in diverse food products.

Restricted access

Abstract

Food industrial bacterial cells eliminate aflatoxin M1 (AFM1) at different ratios. The study aimed to investigate the effect of AFM1 on probiotic industrial bacteria (Lactococcus lactis ssp. lactis R703, Bifidobacterium animalis ssp. lactis BB12, and L. paracasei subsp. paracasei 431) and evaluating their AFM1 binding ability in naturally contaminated milk. The growth of the R703 strain was affected by AFM1 at 1.47 μg L−1 concentration. Peptidoglycan (PG) cell wall fractions of R703 and BB12 bound a significant amount of AFM1 from naturally contaminated milk under one-hour treatment, while L. paracasei 431 was not effective. PG was better absorbent for AFM1 than viable cells of BB12, while the difference was insignificant for the R703 strain. Increasing the time did not significantly change the mycotoxin binding of BB12, while for R703 PG the absorption seemed reversible. BB12 PG needs further analysis for biotechnological application in dairy products.

Open access

Abstract

The aim of this work was to microencapsulate propolis phenolic compounds using polycaprolactone as wall material by double emulsion solvent evaporation (w1/o/w2). Microencapsulation experiments were carried out by investigating the effect of sample/solvent ratio (10–100 mg mL−1), poly(ε-caprolactone) (PCL) concentrations (200–1,000 mg mL−1), poly(vinyl alcohol) (PVA) concentrations (0.5–2.5 g mL−1), and stirring speed (200–1,000 r.p.m.) on the microencapsulation efficiency of total phenolic content (TPC%) and antioxidant activity of propolis. The best microencapsulation conditions were selected according to the total phenolic amount and their antioxidant activity. Experimental results showed that all microencapsulation conditions had significant effects (P < 0.05) on total phenolic content and antioxidant activities. The best conditions were: 30 mg mL−1, 600 mg mL−1, 2 g mL−1, and 400 r.p.m. for sample/solvent ratio, PCL concentrations, PVA concentrations, and stirring speed, respectively, with values of 86.98 ± 0.03% for phenolic encapsulation efficiency, 53.81 ± 0.50% for free radical scavenging activity (DPPH), and 45,480 Trolox equivalent, mg TE/100 g dry weight for ferric reducing antioxidant power (FRAP). Under all encapsulation conditions, a significant positive correlation was observed between ferric reducing antioxidant power, free radical scavenging activity, and phenolic content.

Restricted access
Acta Alimentaria
Authors:
C.V. Raimundi
,
B.C. Scopel
,
A.N. Ito
,
A.A.L. Tribst
,
G.A.R. Sehn
,
D. Cavalheiro
, and
E. Rigo

Abstract

The effects of milk from different species (sheep/cow) and pH adjustment in the production of Requeijão cremoso, a kind of processed cheese, were investigated. The results showed that the sheep's Requeijão cremoso had higher pH (∼3%), lower yellowness index (∼11%), and lower brightness (∼12%) after 5 days of storage, and at least 40% lower hardness compared to the Requeijão made from cow milk. The pH adjustment did not change the visual appearance of the samples but affected their hardness in different ways, with an increase of up to 16% for the cheese from cow milk and a reduction of up to 39% for the cheese produced from sheep milk. The results suggested that the protein-protein interactions were favoured in the Requeijão cremoso from sheep milk, while a protein network with higher water holding capacity and increased hardness was observed for the samples from cow milk.

Restricted access

Abstract

This work used a carrageenan-based thrombosis model to determine the preventative effects of Lactobacillus plantarum YS1 (LPYS1) on thrombus. In thrombotic mice, LPYS1 improved the activated partial thromboplastin time (APTT), while decreasing the thrombin time (TT), prothrombin time (PT), and fibrinogen (FIB) content. In thrombotic mouse serum, LPYS1 decreased the levels of malondialdehyde (MDA), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), nuclear factor kappa-B (NF-κB), and interleukin-1 beta (IL-1β), while also increasing the activities of superoxide dismutase (SOD) and catalase (CAT). Moreover, LPYS1 upregulated the mRNA expression levels of copper/zinc-SOD (Cu/Zn-SOD), manganese-SOD (Mn-SOD), and CAT in the colon tissues of thrombotic mice, while downregulating those of NF-κB p65, IL-6, TNF-α, and interferon-gamma (IFN-γ) mRNA. In tail vein vascular tissues, LPYS1 suppressed the mRNA expression levels of NF-κB p65, intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. The abundances of both beneficial and pathogenic bacteria were altered by LPYS1. These findings show that LPYS1 has the capacity to protect mice from thrombosis, while also revealing some of the underlying mechanisms of this effect.

Open access