Physicochemical Characteristics of Porous Starch Obtained by Combined Physical and Enzymatic Methods, Part 1: Structure, Adsorption, and Functional Properties.

Porous starch can be applied as an adsorbent and encapsulant for bioactive substances in the food and pharmaceutical industries. By using appropriate modification methods (chemical, physical, enzymatic, or mixed), it is possible to create pores on the surface of the starch granules without disturbing their integrity. This paper aimed to analyze the possibility of obtaining a porous structure for native corn, potato, and pea starches using a combination of ultrasound, enzymatic digestion, and freeze-drying methods. The starch suspensions (30%, w/w) were treated with ultrasound (20 kHz, 30 min, 20 °C), then dried and hydrolyzed with amyloglucosidase (1000 U/g starch, 50 °C, 24 h, 2% starch suspension). After enzyme digestion, the granules were freeze-dried for 72 h. The structure of the native and modified starches were examined using VIS spectroscopy, SEM, ATR-FTIR, and LTNA (low-temperature nitrogen adsorption). Based on the electrophoretic mobility measurements of the starch granules using a laser Doppler velocimeter, zeta potentials were calculated to determine the surface charge level. Additionally, the selected properties such as the water and oil holding capacities, least gelling concentration (LGC), and paste clarity were determined. The results showed that the corn starch was the most susceptible to the combined modification methods and was therefore best suited for the production of porous starch.

The Use of Iron-Enriched Yeast for the Production of Flatbread.

The most common cause of iron deficiency is an improperly balanced diet, in which the body's need for iron cannot be met by absorption of this element from food. Targeted iron supplementation and food fortification may be the main treatments for iron deficiency in the population. However, many iron-rich supplements and foods have low bioavailability of this element. In our study, we used yeast enriched with iron ions to produce flatbread. The yeast cells accumulated iron ions from the medium supplemented with Fe(NO3)3·9H2O, additionally one of the cultures was treated with pulsed electric field in order to increase the accumulation. The potential bioavailability of iron from flatbread containing 385.8 ± 4.12 mg of iron in 100 g dry mass was 10.83 ± 0.94%. All the flatbreads had a moderate glycemic index. There were no significant differences in antioxidant activity against DPPH• between flatbread with iron-enriched and non-iron-enriched yeast. Sensory evaluation showed that this product is acceptable to consumers since no metallic aftertaste was detected. Iron enriched flatbread can potentially be an alternative to dietary supplements in iron deficiency states.

Nutritional, Physiochemical, and Biological Value of Muffins Enriched with Edible Insects Flour.

Edible insects are gaining attention as a novel food; however, studies with their use in food are still limited. This study aimed to determine the chemical composition, physical parameters, sensory acceptance, and biological properties of muffins enriched with different levels of cricket (Gryllodes sigillatus) and mealworm (Tenebrio molitor) flours. The approximate composition was analyzed, along with the physical and textural properties, color, and consumer acceptance. Moreover, the antioxidant properties, starch digestibility, and glycemic index were determined in vitro. As we expected, the protein content in muffins supplemented with insect flour increased, while the carbohydrates content decreased. Moreover, the total phenolic content and antioxidant capacity against ABTS·+ and DPPH· increased correspondingly as the percentage of insect flour in the muffins increased. The estimated glycemic index was lower for the fortified muffins than the control (p < 0.05). Additionally, enriched muffins were accepted by consumers, and their taste positively surprised respondents (p < 0.05). Therefore, the results obtained are satisfactory as regards the use of insects for the supplementation of traditional products, and further research into the addition of insects to other nutrient matrices is needed. Furthermore, examining the effect of insect addition on in vivo food biological activity is highly desirable.

Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae.

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 µs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.

Effect of Various Types of Intermittent Fasting (IF) on Weight Loss and Improvement of Diabetic Parameters in Human.

PURPOSE OF REVIEW: A number of recent studies have suggested that intermittent fasting is as effective as traditional calorie restriction (CR) for weight loss and for cardioprotection. However, it is still unclear whether IF improves diabetes risk indicators as does CR. This review provides an overview of various patterns of intermittent fasting and shows the effect of intermittent fasting on human anthropometric such as excess body weight and biochemical parameters for example high glucose and fasting insulin, which are risk factors for diabetes. RECENT FINDINGS: There is a growing body of evidence pointing to the benefits of intermittent fasting for glucose and insulin homeostasis, but this should be confirmed by further studies in population groups with (or at high risk) type II diabetes and insulin resistance. Long-term studies are also needed that could reveal potential negative health effects that some studies report. Eleven studies in overweight/obese adult people that included changes in weight, body composition, and diabetic parameters (fasting glucose, fasting insulin, HbA1c concentration, and HOMA-IR index) were published between 2012 and 2020. Seven studies concerning the effects of alternate day fasting (ADF) on weight loss and diabetic parameters were analyzed. All of them have shown the effects of ADF on weight loss and slight improvement in diabetic parameters. For time-restricted feeding (TRF), a significant improvement in the HOMA-IR index was observed in 2 studies. One study saw an increase in fasting glucose. An analysis of 2 studies using a complete alternate day fasting (CADF) was performed. One study showed decrease in fasting glucose and insulin, and in one a decrease in glycosylated hemoglobin (HbA1c) was observed. CONCLUSION: Different types of intermittent fasting reduce body weight and reduce diabetes parameters such as fasting glucose, fasting insulin, HOMA-IR index, and glycated hemoglobin (HbA1c).

Effect of electroporation in a continuous flow system on bioaccumulation of magnesium, zinc and calcium ions in Lactobacillus rhamnosus B 442 cells.

Biomass of Lactobacillus rhamnosus B 442 was subjected to the continuous electroporation using an electroporator with a flow chamber (length of 10 cm, distance between electrodes 0.25 cm, stream width 0.25 cm, flow speed 10 mL/min) to improve accumulation of calcium, magnesium and zinc in the cells. For all tested ions, the following parameters were applied: voltage of 250 V (E = 1 kV/cm), 570 V (E = 2.28 kV/cm), 950 V (E = 3.8 kV/cm), and 1400 V (E = 5.6 kV/cm, the positive control), a frequency of 10 Hz, a pulse width of 100 µs and 30 electrical pulses. The use of PEF increased the accumulation of magnesium, zinc and calcium by 39, 73 and 162%, respectively, compared to the control. Positive correlation was found between ion accumulation and membrane permeability for zinc and magnesium. For calcium, the initial increase in permeability resulted in higher ion accumulation, but with a further increase of this parameter at 3.8 kV/cm, its decrease was observed caused by a drop in cell viability. Total number of bacteria ranged from 1.67 × 108 (for the cultures supplemented with calcium) to 1.34 × 1012 cfu/mL (for the cultures supplemented with magnesium).

The application of PEF technology in food processing and human nutrition.

During the last decades, many novel techniques of food processing have been developed in response to growing demand for safe and high quality food products. Nowadays, consumers have high expectations regarding the sensory quality, functionality and nutritional value of products. They also attach great importance to the use of environmentally-friendly technologies of food production. The aim of this review is to summarize the applications of PEF in food technology and, potentially, in production of functional food. The examples of process parameters and obtained effects for each application have been presented.

Effect of rapeseed oil aromatisation with marjoram on the content of volatile fraction and antioxidant properties.

The aim of the paper was to study how the process of aromatisation with marjoram affected the composition of volatile fraction and antioxidant properties of rapeseed oil. Different methods of aromatisation were used: direct addition of marjoram essential oil, classical macerations of marjoram herb, and maceration assisted with ultrasound or microwave. The dominant aromatic component in the volatile fraction was γ-terpinene with concentration in the range from 3.15 µg/mL (microwave assisted maceration) to 8.82 µg/mL (classic maceration with shaking). The content of this compound in the mixture of rapeseed oil with essential oil was 152.09 µg/mL. The sample aromatized by the direct addition of essential oil contained the highest amount of volatile substances but simultaneously it had the lowest antioxidant activity.

Influence of Pulsed Electric Field on Accumulation of Calcium in Lactobacillus rhamnosus B 442.

Calcium is an element that performs many important functions in the human body. A study was conducted on the use of a pulsed electric field (PEF) to enrich cells of Lactobacillus rhamnosus B 442 in calcium ions. The highest concentration of calcium ions in bacterial cells (7.30 mg/g d.m.) was obtained at ion concentration of 200 µg/ml of medium and with the use of the following PEF parameters: field strength 3.0 kV/cm, exposure time 10 min, pulse width 75 ms and 20 h of culturing after which bacteria were treated with the field. Cell biomass varied in the range from 0.09 g/g d.m. to 0.252 g/g d.m., and the total number of bacteria ranged from 1010 CFU/ml to 1012 CFU/ml. Microscope photographs prove that calcium ions were situated within the cells of the bacteria, and electroporation contributed to an increase in the effectiveness of the ion bioaccumulation process. Samples containing calcium and subjected to electroporation displayed intensive fluorescence. The significance of this research was the possibility of using probiotic bacteria enriched with calcium ions for the production of functional food in subsequent studies.

Effects of Ultrasound Technique on the Composition of Different Essential Oils.

The objective of the experiment was to investigate the stability of the composition of selected essential oils in the model systems containing methanol and hexane solutions which were treated with ultrasound. Solutions of the oils, with a concentration of 90 mg/ml, were subjected to the effect of ultrasounds with a frequency of 20 kHz and an output power of 200 W for periods of 2 min and 10 min at 50% and 80% power. The experiment has shown no significant effect on the composition of the essential oils resulting from the applied parameters of the process in the tested model systems. The study indicates that the sonication parameters adopted in the experiment can be applied in the case of analogous systems containing essential oils in their composition.

Sensory and chemical evaluation of tea brews prepared with the assistance of ultrasound / Avaliação sensorial e química de infusões de chás preparados com o emprego do ultrassom

ABSTRACT: The aim of the study was to evaluate sensory and phytochemical (polyphenols, flavonoids and caffeine) estimation of black and green tea brews obtained in an alternative way through brewing with the assistance of ultrasound. Brews produced with the application of sonication for 2 minutes and 1 minute were the most preferred by the sensory evaluation team. Evaluation of the brews in terms of component descriptors, i.e. fragrance, flavour and colour, was varied and depended on the kinds of tea and on the applied experimental factors. It was demonstrated that ultrasound have a significant effect on the extraction of active substances, i.e. polyphenols, flavonoids and caffeine, from black and green tea. The application of sonication caused a significant increase in the concentration of flavonoids (by ca. 29% and 73%), polyphenols (by ca. 34% and 41%) and caffeine (by ca. 51% and 60%) in the tea brews.

RESUMO: O objetivo do estudo foi verificar a atividade sensorial e fitoquímica (polifenóis, flavonóides e cafeína) de infusões de chá preto e verde empregando o ultrassom. As infusões produzidas com a aplicação de sonicação por 2 e 1 minutos foram as mais preferidas pela equipe de avaliação sensorial. A avaliação das infusões em termos de descritores de componentes, isto é, fragrância, sabor e cor, foi variada e dependeu dos tipos de chás e dos fatores experimentais aplicados. Foi demonstrado que o ultrassom tem um efeito significativo na extração de substâncias ativas, ou seja, polifenóis, flavonóides e cafeína, do chá preto e verde. A aplicação de sonicação causou um aumento significativo na concentração de flavonóides (em cerca de 29% e 73%), polifenóis (em cerca de 34% e 41%) e cafeína (em cerca de 51% e 60%) das infusões de chá.

Porous starch and its application in drug delivery systems.

In recent years, starch has become a new potential biomaterial for pharmaceutical applications. This biopolymer has unique physicochemical and functional characteristics, as well as various advantages such as low price, relative ease of isolation in pure form from the plant source, non-toxicity, biodegradability, good biocompatibility, and interaction with living cells. Starch is currently used in pharmacy as a binder, disintegrating agent, film-forming material, raw material for production of microspheres and nanoparticles, and a component of drug delivery systems. Porous starch, which can be obtained with physical, chemical and enzymatic methods of modification, has a large specific surface area thanks to the presence of pores and channels. It has excellent adsorption capacity and can be used to enhance the dissolution rate of poorly soluble drugs or as shell material to improve the stability and water-solubility of compounds. As a component of drug delivery systems, porous starch has another advantage: it is biodegradable, so there is no need to remove it from the body after the release of the active agent.

Ultrasonic modification of starch - Impact on granules porosity.

Rice, corn, wheat, and potato starch granules suspended in water or ethanol were treated with ultrasounds at frequency of 20kHz and power 170W for 30min. Porosity of starch was investigated in terms of specific surface area (SBET), average pore size and pore size distribution using low-temperature nitrogen adsorption method. The significant increase of SBET was noted for all the studied starches sonicated in water and for potato starch modified in ethanol. Ultrasonic treatment influenced the average diameter of mesopores (2nm

Effect of pulsed electric fields (PEF) on accumulation of selenium and zinc ions in Saccharomyces cerevisiae cells.

The cultures of Saccharomyces cerevisiae were treated with pulsed electric fields (PEF) in order to obtain a maximum accumulation of selenium and zinc ions (simultaneously) in the biomass. The following concentrations: 100µgSe/ml and 150µgZn/ml medium were assumed to be optimal for the maximum accumulation of these ions, that is 43.07mg/gd.m. for selenium and 14.48mg/gd.m. for zinc, in the cultures treated with PEF. At optimal PEF parameters: electric field strength of 3kV/cm and pulse width of 10µs after the treatment of 20-h culture for 10min, the maximum accumulation of both ions in the yeast cells was observed. Application of PEF caused the increase of ions accumulation by 65% for selenium and 100% for zinc. Optimization of PEF parameters led to the further rise in the both ions accumulation resulting in over 2-fold and 2.5-fold higher concentration of selenium and zinc.

Bioaccumulation of the Selected Metal Ions in Saccharomyces cerevisiae Cells Under Treatment of the Culture with Pulsed Electric Field (PEF).

The obtained results demonstrated an influence of PEF on increase in accumulation of various ions in S. cerevisiae cells. Optimization of particular PEF parameters and ions concentrations in the medium caused twofold increase in accumulation of magnesium and zinc ions and 3.5-fold higher accumulation of calcium ions in the cells. In the case of ion couple, accumulation of magnesium and zinc was, respectively, 1.5-fold and twofold higher in comparison to the control cultures. Yeast cells biomass enriched with Mg(2+), Zn(2+), Ca(2+) as well as Mg(2+) and Zn(2+) (simultaneously) may be an alternative for pharmacological supplementation applied in deficiency of these cations.

Visualization of calcium and zinc ions in Saccharomyces cerevisiae cells treated with PEFs (pulse electric fields) by laser confocal microscopy.

The aim of the present work was to visualize the areas of increased concentration of calcium and zinc ions inside Saccharomyces cerevisiae cells with the use of confocal microscopy and to make an attempt to asses semi-quantitatively their concentration within the limits of the cells. Semi-quantitative analysis revealed that fluorescence inside cells from control samples was three-times lower than that observed for cells from the sample enriched with calcium. Differences in distribution of fluorescence intensity between cells originated from the samples enriched with zinc and control samples were also observed. On the basis of the optical sections, the 3D reconstructions of ion-rich areas distribution in the cell were made. The obtained results showed that confocal microscopy is a useful technique for visualization of the areas in S. cerevisiae cells which contain higher amount of calcium and zinc and it may be also used for semi-quantitative analysis.

Effect of pulse electric fields (PEF) on accumulation of magnesium and zinc ions in Saccharomyces cerevisiae cells.

Cultures of Saccharomyces cerevisiae were treated with PEF to improve simultaneous accumulation of magnesium and zinc ions in the biomass. The results showed that the ions concentration in the medium and their mutual interactions affect accumulation in cells. Increasing the concentration of one ion in the medium reduced the accumulation of the second one, in the control as well as in the cells treated with PEF. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEF of 5.0 kV/cm and 20 µs pulse width, accumulation of magnesium and zinc in yeast biomass reached maximum levels of 2.85 and 11.41 mg/gd.m., respectively, To summarize, optimization of ion pair concentration and PEF parameters caused a 1.5 or 2-fold increase of magnesium and zinc accumulation, respectively, in S. cerevisiae.