Perceptions of the health and convenience characteristics of fresh and dried fruits

Dried fruits consumption has not received much research attention, although these foods are associated with potential health benefits. Therefore, the aim of this study was to compare fresh fruits and dried fruits on measures of health, convenience and consumer feelings.An on-line questionnaire that measured consumers' perceptions of the health benefits and convenience characteristics and their feelings about the consumption of both fresh fruits (apples and plums) and dried fruits (e.g., raisins, dates, and apricots) was completed by 693 respondents (Polish, French, and Dutch).Generally, fresh fruits were perceived to be healthier and less convenient than dried fruits. Consumers also reported more positive feelings about the consumption of fresh fruits compared to dried fruits. The more that the respondents were willing to sacrifice for their health, the more positively they rated the health aspects of both fresh and dried fruits, as well as several perceptions of convenience of both fresh and dried fruits. Health preoccupation was unrelated to most of the convenience perceptions and was associated with lower scores on several perceptions of healthiness. Recommendations for the consumer-oriented development of dried fruits are also provided.     

Influence of Pulsed Electric Field Protocols on the Reversible Permeabilization of Rucola Leaves

Reversible electropermeabilization of plant tissues with heterogeneous structure represents a technological challenge as the response of the different structures within the same specimen to the application of electric field may differ due to different cell sizes, extracellular space configurations, and electrical properties. The influence of five different pulsed electric field protocols with different pulse polarity, number of pulses (25, 50, 75, 100, 250, and 500), and intervals between pulses (no intervals and 1- and 2-ms intervals) on the reversible permeabilization of rucola (Eruca sativa) leaves was investigated. The electric field intensity was 600 V/cm. Electrical resistance of the bulk tissue was measured before and after electroporation, and propidium iodide was used to analyze the electroporation at the surface of the leaf. Leaf viability was assessed from survival in storage, and cell viability was investigated with fluorescein diacetate. Results indicate that the viability of the leaves could not be predicted by measurements of electrical resistance or permeabilization levels of the leaf surface. Higher survival rate was demonstrated when applying bipolar pulses compared with monopolar pulses, but the latter proved to be more effective than bipolar pulses for permeabilizing the surface of the leaves. Longer intervals between bipolar pulses resulted in increased viability preservation, while the number of electroporated cells on the leaf surface was comparable for all tested protocols.     

The Usefulness of Intermediate Products of Plum Processing for Alcoholic Fermentation and Chemical Composition of the Obtained Distillates

In this study, an evaluation of intermediate products of plum processing as potential raw materials for distillates production was performed. Effects of composition of mashes on ethanol yield, chemical composition and taste, and flavor of the obtained spirits were determined. The obtained results showed that spontaneous fermentations of the tested products of plum processing with native microflora of raisins resulted in lower ethanol yields, compared to the ones fermented with wine yeast Saccharomyces bayanus. The supplementation of mashes with 120 g/L of sucrose caused an increase in ethanol contents from 6.2 ± 0.2 ÷ 6.5 ± 0.2% v/v in reference mashes (without sucrose addition, fermented with S. bayanus) to ca. 10.3 ± 0.3% v/v, where its highest yields amounted to 94.7 ± 2.9 ÷ 95.6 ± 2.9% of theoretical capacity, without negative changes in raw material originality of distillates. The concentrations of volatile compounds in the obtained distillates exceeding 2000 mg/L alcohol 100% v/v and low content of methanol and hydrocyanic acid, as well as their good taste and aroma make the examined products of plum processing be very attractive raw materials for the plum distillates production.     

Effects of metal cations on betanin stability in aqueous-organic solutions

An effect of metal cations on betanin stability was investigated in aqueous and organic-aqueous solutions. The presence of organic solvents (methanol, ethanol, and acetonitrile) affects substantially the pigments decomposition in acidic media induced by metal cations whose degrading action in such media is significantly higher than in aqueous solutions. The influence of Cu²⁺ on the stability was studied by spectrophotometry in more detailed manner, because of its ability to form complexes with betanin. The possibility of a complex formation between betanin and Ni²⁺ was also stated at pH 7–8; its relatively high stability in aqueous samples was observed. A presence of numerous products of betanin decomposition was detected in the wavelength range 380–500 nm in spectra obtained for most of metal cations investigated, especially for higher concentrations of the organic solvents.     

Chemical composition and antioxidant activity of Korean cactus (Opuntia humifusa) fruit

The chemical composition and antioxidant activities of the Korean cactus (Opuntia humifusa, OH) fruit were investigated in this study. Major minerals in the OH fruit were P, Ca, and Mg. Total dietary fiber content was 22.8% and the soluble dietary fiber/insoluble dietary fiber ratio was 1:1.3. An 80% ethanol extract was used to investigate antioxidant activities based on DPPH radical scavenging ability as well as total phenolic and flavonoid content. OH fruit extract from 80% ethanol was sequentially fractionated according to the polarity of solvents. Among various fractions, the ethyl acetate fraction showed the highest antioxidant activity as well as the highest total phenolic and total flavonoid contents compared to other fractions. The most abundant phenolic acid in the ethyl acetate fraction was ferulic acid, followed by protocatechuic acid. The most abundant flavonoid was taxifolin, followed by myricetin. The results suggested that OH fruit could be a good potential source of antioxidant.     

Investigation of iodine bioavailability from chicken eggs versus iodized kitchen salt with in vitro method

The goal of the presented studies was to investigate speciation and bioavailability of iodine from chicken eggs versus iodized kitchen salt with an in vitro method. Determination of iodine total content in chicken eggs and iodized kitchen salt was carried out by inductively coupled plasma mass spectrometry (ICP MS). The majority of iodine was accumulated in the yolk—the concentration was even 37 times higher than in white. Chicken eggs were treated with buffer (Tris HCl pH = 7.5) and enzymatic extraction media and analyzed by size exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC ICP MS). The enzymatic extraction being an in vitro bioavailability assessment method was based on two-stage digestion model simulating gastric (pepsin digestion) and intestinal (pancreatin digestion) juices. Speciation analyses along with bioavailability studies presented iodide as the major form in chicken eggs. The bioavailability was established as 33% from white and 10% from yolk and decreased with longer time of boiling. It allows to suggest that the majority of iodine remains in forms bound to non-digestible coagulated and water-insoluble proteins.     

Linear correlation between pH value of stimulated beef and electrical current intensity

The aim of the present study was to determine mathematical relationships between pH changes in beef 24 h post-slaughter and changes in the intensity of electrical current flowing through bull and heifer carcasses during high-voltage electrical stimulation. The electrical stimulation was applied 40 min postmortem for 120 s. The pH values of m. longissimus thoracis et lumborum were analyzed in the function of electrical current intensity changes and its change during electrical stimulation. Mathematical linear correlations of the y = ax ± b type were demonstrated between pH values at 2, 6, and 24 h postmortem and the initial (I_i) and ultimate (I_u) electrical current intensity values, the difference between them and the initial pH values determined before electrical stimulation. High multiple correlation coefficients (R² = 0.416, α ≤ 0.001) between I_u and pH values 24 h post-slaughter enabled concluding that there is a possibility to predict a pH value of stimulated carcass with high accuracy, and thus also beef quality, based merely on the ultimate electrical current intensity values.     

Changes of bioactive components in berry seed oils during supercritical CO2 extraction

The objective of the work was to elucidate the chemical composition of fractions of oil extracts obtained during the supercritical extraction on a semi‐industrial scale from strawberry (Fragaria x ananassa Duch.), chokeberry [Aronia melanocarpa (Michx.)], and raspberry (Rubus idaeus L.) seeds from industrial press cake. The oil extracts differed in terms of their content of bioactive components: carotenoids, tocopherols, chlorophylls, and fatty acids. Raspberry seed oil was the richest source of tocopherols (620.1–2166.7 mg kg^?1) and α‐linolenic acid (above 37%). Chokeberry seed oil had the highest content of linoleic acid (above 70%), and α‐tocopherol (166.0–1104.8 mg kg^?1). Strawberry oil was characterized by the highest content of chlorophylls and α‐linolenic acid (above 30%). It was showed that the oil fraction collected at the beginning of extraction is characterized by a high acid value, which requires purification steps to be used for food purposes.

Practical applications

Strawberry, raspberry, and chokeberry by‐products left over from the production of concentrated juice are a valuable source of oils rich in n‐3 and n‐6 polyunsaturated fatty acids, tocopherols, and carotenoids. The research showed that the fractionation of extracts in the course of supercritical extraction leads to oils with varying amounts of different bioactive compounds, and thus to products with potentially wide applications. Seeds oils have high potential utility as a source of unconventional oil for cosmetic and pharmaceutical sectors and biodiesel. Their targeted utilization may be exploited for economic, environmental and health benefits.     

Characteristics of lactose-free frozen yogurt with κ-carrageenan and corn starch as stabilizers

Frozen yogurt is a type of dairy product that is considered to be a more healthful alternative to conventional ice cream due to its lower fat content and the presence of viable lactic acid bacteria. Lactose-free products are a growing trend in the dairy industry, and lactose-free yogurts and ice creams can both be found on the market. However, lactose-free frozen yogurt has not yet reached the market. In this study, we aimed to investigate the effect of adding κ-carrageenan (0.05, 0.1, and 0.15%) and corn starch (1, 2, and 3%) on acidity, texture, viscosity, overrun, melting properties, color attributes, and sensory characteristics of lactose-free frozen yogurts. Lactose was reduced by enzymatic hydrolysis during the fermentation process. The effectiveness of the hydrolysis was measured by HPLC, and lactose was reduced to 0.05% after 80 min of incubation with the enzyme. The addition of stabilizers did not change overrun and melting properties of frozen yogurt, but it did affect pH, titratable acidity, and color parameters. The product with 0.15% κ-carrageenan had the highest hardness and stickiness values. Moreover, κ-carrageenan had a positive effect on sensory attractiveness of lactose-free frozen yogurt, and it reduced the coarse texture in comparison with the control without stabilizers. A lactose-free frozen yogurt with good quality and nutritional characteristics was produced, particularly with the use of κ-carrageenan as stabilizer.