Vacuum impregnation and air drying temperature effect on individual anthocyanins and antiradical capacity of blueberry juice included into an apple matrix

Vacuum impregnation: Effect on food quality, application and use of novel techniques for improving its efficiency

Vacuum Impregnation (VI) act as promising method for rapidly introducing specific concentration solutions into food matrices using a hydrodynamic mechanism and deformation phenomenon to attain a product with specific tailored functional quality characteristics. VI facilitates rapid introduction of specific solutions into the food matrices. This technique allows efficient incorporation of bioactive compounds and nutritional components, meeting the rising consumer demand for functional foods. Furthermore, VI when combined with non-thermal techniques, opens up new avenues for preserving higher quality attributes and enhancing antimicrobial effects. The unique ability of VI to rapidly infuse specific solutions into food matrices, combined with the advantages of non-thermal processes, addresses the growing consumer demand for products enriched with bioactive ingredients. Hence, the present review aims to explore the potential impact of VI, coupled with novel techniques, on food quality, its practical applications, and the enhancement of process efficiency for large-scale industrial production.

Improving Structural, Physical, and Sensitive Properties of Sodium Alginate-Purple Sweet Potato Peel Extracts Indicator Films by Varying Drying Temperature

Sodium alginate (SA)-purple sweet potato peel extracts (PPE) from industrial waste indicator films were developed at different drying temperatures (25, 30, 35, 40, 45, 50, and 55 °C). The effects of drying temperatures on the film's structural, physical, and sensitive properties were investigated. On the structural properties, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction indicated that compactness, intermolecular interactions, and crystallinity of indicator films were improved at a lower drying temperature. On the physical properties, with the drying temperature increasing, elongation at the break increased significantly (p < 0.05); ΔE and water-vapor permeability decreased significantly (p < 0.05); and thickness and tensile strength initially increased significantly (90.46 → 98.46, 62.99 → 95.73) and subsequently decreased significantly (98.46 → 71.93, 95.73 → 55.44) (p < 0.05), with the maximum values obtained at 30 °C. On sensitivity, the corresponding colors of the films became lighter as the drying temperature increased, and the films exhibited relatively excellent pH and NH3 sensitivity, with easily discernible color changes at lower temperatures. The results of this paper revealed that the overall film characteristics are improved at lower drying temperatures, which will provide valuable references for selecting the drying temperature for preparing indicator films as a guide for industrialized production.

Development and evaluation of a vacuum impregnation system for enhancement of biochemical properties of food materials

Vacuum impregnation is a novel methodology for adding various substances to porous foods. This study aimed to develop a cost effective automate system for vacuum impregnation of food materials to enhance their nutritional, functional and sensory properties depending on the functionality of the impregnation solution. The developed vacuum impregnation system includes a vacuum chamber, vacuum pump and an automation setup for creating and maintaining vacuum conditions, feeding impregnated solutions to the samples and releasing vacuum. Fresh-cut spinach leaves were impregnated with ascorbic acid (AsA) and calcium chloride (Cacl2) (10% concentration) in the setup in order to test the effect of the process on some biochemical properties. Statistical analysis revealed significant effect of vacuum impregnation on the biochemical properties (total soluble solids, total phenolic content, flavonoid content and free radical scavenging activity) and color of spinach leaves during storage up to 4 days. Impregnation process showed significant increase in the total phenolic and flavonoid content of the spinach leaves. Increment up to 78% in antioxidant activity was seen for the uncoated impregnated leaves as compared to 59% activity in untreated samples. Thus, products with desired parameters can be produced with this process with minimal impact on their properties at a lower cost and in a shorter time period.

Assessment of ultrasound-assisted vacuum impregnation as a method for modifying cranberries' quality

Combined vacuum impregnation and ultrasound was proposed as an alternative method to improve the infusion of ascorbic acid in berry fruit. The effect of ultrasound application at different stages of impregnation - vacuum, relaxation, and both stages - on the qualitative characteristics of impregnated cranberries was investigated. The quality assessment was based on porosity, color, antioxidant capacity, anthocyanin, polyphenol and structure compound content. Ultrasound-assisted vacuum impregnation contributed to higher ascorbic acid content, smaller relative color difference, and greater antioxidant properties. It was found that the degree of impregnation varies considerably and depends on the stage of using ultrasound. Due to more favorable quality attributes, the conclusion was reached that ultrasound should be applied during the relaxation stage of vacuum impregnation.

Study of Water Distribution, Textural and Colour Properties of Cold Formulated and Air-Dried Apple Snacks

Vacuum impregnation is considered a cold formulation technology since it allows the incorporation of a desired functional compound into porous plant tissue without applying any heat. It is widely used in combination with the drying process to obtain added-value snacks. The aim of this work was to evaluate the effect of two trehalose concentrations (5 and 10% w/w) on: (i) the water state and texture evolution during the air drying (50 °C, 8 h) of apple snacks vacuum impregnated with blueberry juice, and on (ii) the colour of the final dried apple snacks. The results of nuclear magnetic resonance (NMR) showed that trehalose affects the water mobility of the samples during drying especially after 200–300 min of drying. In terms of textural properties, trehalose could increase the crispier characteristic of the samples impregnated with trehalose at the end of drying. Significative changes were found in terms of chroma and hue angle.

Effects of Processing and Storage Conditions on Functional Properties of Powdered Blueberry Pomace

Promoting a circular economy through valorisation of food processing waste into functional ingredients is a challenge today. The combination of hot air drying with milling is a cheap and highly available option for obtaining powdered products from blueberry pomace, a residue with a large amount of fibre and a high proportion of polyphenols from the fruit. The objective of this work was to analyse the effect of drying temperature (60 °C and 70 °C) and granulometry (coarse and fine) on physicochemical properties, including antioxidant properties and monomeric anthocyanins content. The potential prebiotic effect of blueberry pomace powders, as well as their water and oil interaction properties, were also assessed. Stability of physicochemical properties over 20 weeks of storage was also evaluated. Powders obtained showed a total fibre content higher than 30% with a good proportion between insoluble and soluble fractions and a high retention of monomeric anthocyanins from fresh pomace (75% at 60 °C and 66% at 70 °C). The powders showed good water interaction properties and interesting technological properties, such as solubility and hygroscopicity, which were not affected by differences in particle size. Stability of powders’ physicochemical properties was evidenced throughout the storage period.

Power Ultrasound-Assisted Impregnation of Apple Cubes with Vitamin B12

This work explores the use of ultrasound (US) as a means of intensifying the impregnation of apple cubes with vitamin B12 (cyanocobalamin). The effect of different US power densities (90 and 200 WL−1) and treatment times (5, 10, and 15 min) was evaluated, on vitamin load, vitamin stability, and physicochemical and microstructural properties of the fruit matrix. The US enhanced the impregnation producing high cyanocobalamin content products (0.12–0.19 mg vitamin/g db.). Vitamin losses in the sonication medium due to US application were not significant. Impregnated samples exhibited higher moisture and lower soluble solids with respect to the untreated fruit. Changes in chromatic coordinates were well correlated to vitamin uptake. Only at the highest treatment intensities (200 WL−1, 10, and 15 min) was a marked softening observed, which agreed with the microstructural changes observed in fruit tissues. Results permit US-assisted impregnation to be considered a promising technology in the preparation of vitamin B12 fortified apple cubes.

Bioaccessibility of Anthocyanins on in vitro Digestion Mmodels: Factors Implicated and Role in Functional Foods Development

BACKGROUND

Worldwide, the prevalence of obesity and related non-communicable chronic diseases is high and continues to grow. In that sense, anthocyanins (ANC) have shown beneficial health effects in preventing obesity and metabolic risk factors. Moreover, the demand for functional foods incorporating these compounds has risen significantly in the past years. Thus, there is a need for validations of the functional properties of these formulations; nevertheless, in vivo assays are complex and require a lot of resources. One approach for estimating bioactive compounds' functionality and health benefits is to evaluate their bioaccessibility on a specific food matrix, determined by various factors. This article aims to review different factors influencing the bioaccessibility of ANC evaluated on in vitro digestion models as a functionality parameter, elucidating the effect of chemical composition, raw materials, food matrices, and vehicles for the delivery of ANC.

METHODS

Study searches were performed using PubMed, Web of Science, Scopus, and Science Direct databases.

RESULTS

Different factors influenced bioaccessibility and stability of ANC studied by in vitro digestion which are: i) the raw material used for ANC obtention; ii) food processing; iii) other food components; iv) the extraction method and solvents used; v) the structure of ANC; vi) delivery system (e.g., microencapsulation); vii) pH of the medium; viii) the digestion stage.

CONCLUSION

Simulated digestion systems allow to determine free or encapsulated ANC bioaccessibility in different food matrices, which offers advantages in determining the potential functionality of a food product.

Effect of Different Extraction Methods on the Quality and Biochemical Attributes of Pomegranate Juice and the Application of Fourier Transformed Infrared Spectroscopy in Discriminating Between Different Extraction Methods

This study investigated the effects of extraction methods on the physicochemical, phytochemical, and antioxidant properties of pomegranate juice (cv. Wonderful). In addition, the application of attenuated total reflectance Fourier transformed mid-infrared (ATR-FT-MIR) spectroscopy and chemometrics were explored in order to discriminate between different extraction methods. Juice variants evaluated included juice extracted without crushing the seeds (arils only) using a juice extractor (JE), juice extracted by crushing the seeds using a blender (arils plus seed) (JB), and juice extracted from half fruit using a commercial hand press juicer (CH). Juice extracted from CH had higher total soluble solid (TSS) content (18.20%), TSS/TA ratio (15.83), and color properties (a^* = 32.67, b^* = 11.80, C^* = 34.77) compared with extraction methods JE and JB. The juice extracted from JB showed the highest titratable acidity (2.17%), cloudiness (0.43), and lowest pH value (2.69). The total phenolics and anthocyanin content in the investigated juice ranged from 1.87 to 3.04 g gallic acid equivalent (GAE)/L and 37.74-43.67 mg cyanidin 3-glucoside equivalent/L of crude juice, respectively. Juice extracted from JB and CH was significantly higher in phenolic and anthocyanin compared with JE. Orthogonal partial least squares discriminant analysis (OPLS-DA) and principal component analysis (PCA) were used for classification. Classification accuracy of 100% was achieved between the three methods. The S-line plot revealed that the corresponding wavelength bands within the following regions 1,090, 1,250, 1,750, and 3,200 cm^-1 were responsible for discrimination between the different extraction methods. Our results suggest that the main contributor to the discrimination between extraction methods were TSS, TSS/TA, color attributes, and anthocyanin content. Overall, this study has demonstrated that ATR-FT-MIR spectroscopy provides a powerful way to discriminate between juice extraction methods.

High efficient freeze-drying technology in food industry

Freeze-drying technology is an interdisciplinary and complex technology, combined with freezing and vacuum drying, It has become an important technology for heat-sensitive drugs and food preservation. Freeze-dried foods are classified into meat, vegetables, fruits, fungus, and micro-powders, etc. In this paper, the definition, principle, steps, advantages and disadvantages of freeze-drying are summarized, and the research progress of freeze-drying in food industry in recent years is reviewed, including the technological parameters and influencing factors.

Valorization of Persimmon and Blueberry Byproducts to Obtain Functional Powders: In Vitro Digestion and Fermentation by Gut Microbiota

Globalization of fruit and vegetable markets generates overproduction, surpluses, and potentially valuable residues. The valorization of these byproducts constitutes a challenge, to ensure sustainability and reintroduce them into the food chain. This work focuses on blueberry and persimmon residues, rich in polyphenols and carotenoids, to obtain powders with high added value to be used as ingredients in food formulation. These powders have been characterized, and the changes in the bioactive compounds in in vitro gastrointestinal digestion have been evaluated. The results indicated that the type of residue, the drying process, as well as the content and type of fiber determine the release of antioxidants during digestion. In vitro colonic fermentations were also performed, and it was observed that the characteristics of digested powders had an effect on the composition of the growing microbial community. Thus, carotenoids and anthocyanins maintain an interplay with microbiota that could be beneficial for human health.

Influence of Selected Parameters and Different Methods of Implementing Vacuum Impregnation of Apple Tissue on Its Effectiveness

The study provides comprehensive information on the vacuum impregnation process applied to plant materials. It aims (in traditional applications) to ensure impermeability and elimination of porosity of various materials. The process substantially accelerates mass transfer in the liquid–solid system. The study describes the course of the process and accompanying phenomena as well its effects on plant tissues. The aim of the investigations was to determine the impact of some impregnation parameters (pressure, pressure change rate, vacuum maintenance time, relaxation time, and the coefficient of impregnating liquid viscosity) and the mode of impregnation (wet, dry, cyclic wet) on the degree of filling the plant tissue with the impregnating solution. Jonagold apples were used as the study material. The investigations have revealed that changes in the vacuum impregnation parameters (vacuum maintenance time, relaxation time, pressure change rate in the system) and the impregnation method do not exert a significant impact on the effectiveness of the process as expressed by the degree of permeation of the impregnating solution into the tissue. The pressure value and the viscosity coefficient were the only parameters that had a significant effect on the impregnation yield.

The phenolic profile of virgin olive oil is influenced by malaxation conditions and determines the oxidative stability

Phenolic compounds largely contribute to the nutraceutical properties of virgin olive oil (VOO), the organoleptic attributes and the shelf life due to their antioxidant capabilities. Due to the relevance of malaxation in the oil extraction process, we tested the effects of malaxation time on the concentrations of relevant phenolic compounds in VOO, and we evaluated the influence of performing malaxation under vacuum. An increase in malaxation time significantly decreased the concentrations of aglycone isomers of oleuropein and ligstroside but, conversely, increased the oleocanthal and oleacein contents. Additionally, malaxation under vacuum led to an increase in phenolic contents compared to standard conditions carried out at atmospheric pressure. Finally, we explored the possibility of predicting the VOO oxidative stability on the basis of the phenolic profile, and a model (R² = 0.923; p < 0.0001) was obtained by combining the concentration of the VOO phenolic compounds and the main fatty acids.

Manufacturing personalized food for people uniqueness. An overview from traditional to emerging technologies

Personalized nutrition means that we are unique in the way to absorb and to metabolize nutrients as a consequence of our genetic profile and the microbiome that we host in the gut. With the terminology of Personalized Food Manufacturing we want not only to stress the idea of the capability to manufacture food meeting our unique nutritional needs but - based on the idea that eating is a global experience - also to broad this to meet additional personal requirements and expectations, i.e. taste, texture, color, aspect, etc. To address this aim, traditional and advances technologies will have to be employed in new ways and new technological solutions will have to be implemented. All these considerations motivated our paper by which we want to explore and to discuss the technological options having the potential to produce personalized food. After pointing out the main diet styles, firstly we have analyzed the modern approaches of agricultural and animal nutrition in use to manufacture food for narrow group of consumers. Secondly, we have explored emerging technologies at disposal employable to manufacture customized food that meet our uniqueness. Finally the most important market products belonging in the sector of personalized food production have been considered.

Ultrasound-assisted vacuum impregnation on the fortification of fresh-cut apple with calcium and black carrot phenolics

This study evaluated the simultaneous effect of ultrasound on vacuum impregnation process to enhance infusion of calcium lactate and black carrot phenolics into ready to eat apple tissues. A vacuum - ultrasonic equipment was developed for this purpose and effects of different ultrasound powers (96-198 W) at 35 kHz and stage of ultrasound application at vacuum and restoration periods were investigated. The simultaneous application of 130 W ultrasound during vacuum impregnation did not rupture cellular integrity, but it led to increases in calcium content (13.8%), total phenolics (11.8%), total flavonoids (17.3%), total anthocyanins (24.6%) and antioxidant capacities (23.6%) of apple discs compared to non-ultrasound vacuum impregnation. In addition, total population of psychrophilic and mesophilic microorganisms were enumerated in both black carrot infused and non-infused samples and results showed that ultrasound-assisted vacuum impregnation treatment in the presence of black carrot phenolics were highly effective on inhibition of microorganisms growth in apple discs over storage period.

Enrichment of Apple Slices with Bioactive Compounds from Pomegranate Cryoconcentrated Juice as an Osmodehydration Agent

Pomegranate juice is an important source of bioactive compounds, and cryoconcentrated juice is an interesting osmodehydration agent to enrich a vegetal matrix. This investigation aimed to incorporate bioactive compounds from pomegranate cryoconcentrated juice into apple slices using osmodehydration (OD) assisted by pulse vacuum (PV) and ohmic heating (OH). The apple slices (3 × 4 × 0.5 cm) were osmodehydrated using a 47 °Brix pomegranate cryoconcentrated juice at 30, 40, or 50°C for 180 min with an electric field of 6.66 V/cm (50 V) and a 5 min pulsed vacuum. Over the time, all of the treatments applied to the apple slices increased the soluble solids and bioactive compounds compared with the fresh sample. PVOD/OH at 50°C had the highest content of total anthocyanin during processing, and the best results for the total flavonoids were obtained with OD/OH at 50°C and 40°C. The osmodehydration assisted by pulse vacuum and ohmic heating using a cryoconcentrated juice is a useful combined technique to acquire enriched vegetal samples with bioactive compounds.

Identification of spoilage microorganisms in blueberry juice and their inactivation by a microchip pulsed electric field system

Blueberry juice is a healthy and nutritious food that has become increasingly popular worldwide. However, little is known about the microbial groups of this juice that can cause its spoilage. This study aimed to identify the main spoilage microorganisms in blueberry juice and explore whether a microchip pulsed electric field (MPEF) can effectively inactivate them. We performed polymerase chain reaction (PCR) amplification, as well as 16S rDNA, 18S rDNA, internal transcribed spacer (ITS), and 26S rDNA gene sequence analyses. Nine species belonging to eight genera, including Pantoea, Burkholderia, Pichia, Meyerozyma, Cryptococcus, Aureobasidium, Cladosporium, and Penicillium were identified as spoilage microorganisms. Cryptococcus sp., Meyerozyma sp., and Pichia sp. were specific spoilage organisms (SSO) owing to their rising numbers throughout spoilage progression. The effect of MPEF on the potential inactivation of these microorganisms was to induce significant inactivation of viable Cryptococcus sp., Meyerozyma sp., and Pichia sp. This research provides a theoretical basis for the application of MPEF in improving the quality of blueberry juice.

Combined effect of ultrasound, heat, and pressure on Escherichia coli O157:H7, polyphenol oxidase activity, and anthocyanins in blueberry (Vaccinium corymbosum) juice

The objective of this study was to evaluate the effect of different treatments-heat treatment (HT), sonication (SC), thermosonication (TS), manosonication (MS), manothermal (MT), and manothermosonication (MTS) on Escherichia coli O157:H7, polyphenol oxidase (PPO), and anthocyanin content in blueberry juice. First, samples were treated at different temperatures (30, 40, 50, 60, 70, and 80°C) and power intensities (280, 420, 560, and 700W) for 10min. Subsequently, samples were treated using combinations of power intensity and mild temperature for 10min. For further study, samples were treated using HT (80°C), TS (40°C, 560W), MT (350MPa, 40°C), MS (560W, 5min/350MPa), or MTS (560W, 5min, 40°C/350MPa, 40°C) for 5, 10, 15, 20min for each treatment, and the results compared between treatments. HT significantly reduced PPO activation (2.05% residual activity after only 5min), and resulted in a 2.00-log reduction in E. coli O157:H7 and an 85.25% retention of anthocyanin. Escherichia coli O157:H7 was slightly inactivated by TS after 5min (0.17-log reduction), while residual PPO activity was 23.36% and anthocyanin retention was 98.48%. However, Escherichia coli O157:H7 was rapidly inactivated by MTS (5.85-log reduction) after 5min, while anthocyanin retention was 97.49% and residual PPO activity dropped to 10.91%. The destruction of E. coli cells as a result of these treatments were confirmed using SEM and TEM. Therefore, a combination of sonication, high pressure, and mild heat allows the safety of blueberry juice to be maintained without compromising the retention of desirable antioxidant compounds.