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3 pages, 202 KiB

Open AccessEditorial

Special Issue: Processing Foods: Process Optimization and Quality Assessment

by Péter Sipos and Milivoj Radojčin

Processes 2023, 11(3), 851; https://doi.org/10.3390/pr11030851 - 13 Mar 2023

Cited by 1 | Viewed by 1200

Abstract

For a long time, the basic as well as the only function of foods is to provide the nutrients and energy needed for human physiological processes [...] Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

Research

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22 pages, 4037 KiB

Open AccessFeature PaperArticle

Effects of Osmotic Dehydration on the Hot Air Drying of Apricot Halves: Drying Kinetics, Mass Transfer, and Shrinkage

by Ivan Pavkov, Milivoj Radojčin, Zoran Stamenković, Krstan Kešelj, Urszula Tylewicz, Péter Sipos, Ondrej Ponjičan and Aleksandar Sedlar

Processes 2021, 9(2), 202; https://doi.org/10.3390/pr9020202 - 21 Jan 2021

Cited by 21 | Viewed by 4116

Abstract

This study aimed to determine the effects of osmotic dehydration on the kinetics of hot air drying of apricot halves under conditions that were similar to the industrial ones. The osmotic process was performed in a sucrose solution at 40 and 60 °C [...] Read more.

This study aimed to determine the effects of osmotic dehydration on the kinetics of hot air drying of apricot halves under conditions that were similar to the industrial ones. The osmotic process was performed in a sucrose solution at 40 and 60 °C and concentrations of 50% and 65%. As expected increased temperatures and concentrations of the solution resulted in increased water loss, solid gain and shrinkage. The kinetics of osmotic dehydration were well described by the Peleg model. The effective diffusivity of water 5.50–7.387 × 10⁻⁹ m²/s and solute 8.315 × 10⁻¹⁰–1.113 × 10⁻⁹ m²/s was calculated for osmotic dehydration. Hot air drying was carried out at 40, 50, and 60 °C with air flow velocities of 1.0 m/s and 1.5 m/s. The drying time shortened with higher temperature and air velocity. The calculated effective diffusion of water was from 3.002 × 10⁻¹⁰ m²/s to 1.970 × 10⁻⁹ m²/s. The activation energy was sensitive to selected air temperatures, so greater air velocity resulted in greater activation energy: 46.379–51.514 kJ/mol, and with the osmotic pretreatment, it decreased to 35.216–46.469 kJ/mol. Osmotic dehydration reduced the effective diffusivity of water during the hot air drying process. It also resulted in smaller shrinkage of apricot halves in the hot air drying process. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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15 pages, 2320 KiB

Open AccessArticle

Optimising Tropical Fruit Juice Quality Using Thermosonication-Assisted Extraction via Blocked Face-Centered Composite Design

by Norazlin Abdullah and Nyuk Ling Chin

Processes 2021, 9(1), 3; https://doi.org/10.3390/pr9010003 - 22 Dec 2020

Cited by 2 | Viewed by 2370

Abstract

Extraction of tropical fruit juice using simple, efficient, and environmentally friendly technologies is gaining importance to produce high quality juices. Juice from pink-fleshed guava, pink-fleshed pomelo, and soursop was extracted using direct and indirect thermosonication methods by varying intensity, time, and temperature, and [...] Read more.

Extraction of tropical fruit juice using simple, efficient, and environmentally friendly technologies is gaining importance to produce high quality juices. Juice from pink-fleshed guava, pink-fleshed pomelo, and soursop was extracted using direct and indirect thermosonication methods by varying intensity, time, and temperature, and compared to those extracted using water bath incubation. Improvised models of juice yield, ascorbic acid, and total soluble solids responses were generated by eliminating insignificant model terms of the factors in full quadratic model using backward eliminating procedure. Main effects, 3D, or 4D plots for each response were developed based on factors that influenced the response. Results showed that the best extraction method for guava and pomelo juices were within indirect thermosonication method of 1 kW, 55 °C and 30 min, and 2.5 kW, 54 °C and 23 min, respectively. Direct thermosonication method at 10% amplitude, 55 °C for 2 to 10 min was more suitable for soursop juice. Thermosonicated extraction of tropical fruit juice can improve its juice yield, ascorbic acid content, and total soluble solids content. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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11 pages, 1405 KiB

Open AccessFeature PaperArticle

Maintaining Physicochemical, Microbiological, and Sensory Quality of Pineapple Juice (Ananas comosus, Var. ‘Queen Victoria’) through Mild Heat Treatment

by Charlène Leneveu-Jenvrin, Baptiste Quentin, Sophie Assemat and Fabienne Remize

Processes 2020, 8(9), 1186; https://doi.org/10.3390/pr8091186 - 18 Sep 2020

Cited by 16 | Viewed by 6548

Abstract

Shelf life of freshly prepared pineapple juice is short and requires refrigerated conditions of storage. Mild heat treatment remains the easiest way to prolong juice shelf life for small companies. This study was constructed to assess pineapple cv. Queen Victoria juice shelf life [...] Read more.

Shelf life of freshly prepared pineapple juice is short and requires refrigerated conditions of storage. Mild heat treatment remains the easiest way to prolong juice shelf life for small companies. This study was constructed to assess pineapple cv. Queen Victoria juice shelf life from a broad examination of its quality and to propose the most appropriate thermal treatment to increase shelf life without any perceptible decrease in quality. From 25 independent batches of pineapple, collected in different areas and seasons from Reunion Island, the variability of juice physicochemical and microbiological quality was determined. Juice pH values were the highest for fruit harvested in summer, but the juice acidity remained low enough to prevent pathogen spore-forming bacteria growth. During storage at 4 °C, color was modified, and yeasts and molds were the main microbial group exhibiting growth. Assessment of sensory quality resulted in the proposal of a shelf life comprising between three and seven days. Compared to higher temperatures, heat treatment at 60 °C was enough to ensure a good microbiological quality for 30 days, but sensory characteristics and color changes led to the proposal of a shelf life of seven days for pineapple juice treated at 60 °C. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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11 pages, 924 KiB

Open AccessCommunication

The Changes of Flavonoids in Honey during Storage

by Goran Šarić, Nada Vahčić, Danijela Bursać Kovačević and Predrag Putnik

Processes 2020, 8(8), 943; https://doi.org/10.3390/pr8080943 - 6 Aug 2020

Cited by 11 | Viewed by 3987

Abstract

The purpose of this study was to determine the changes in the contents of flavonoids that were the most prevalent in acacia and multifloral honey during one year of storage. Samples were stored in transparent glass containers, at room temperature, on open shelves [...] Read more.

The purpose of this study was to determine the changes in the contents of flavonoids that were the most prevalent in acacia and multifloral honey during one year of storage. Samples were stored in transparent glass containers, at room temperature, on open shelves exposed to light during daytime. Eight individual flavonoids identified and quantified using HPLC-Diode Array Detector (DAD) belongs to three subgroups: flavonols (quercetin, luteolin, kaempferol and galangin), total flavanons (hesperetin and pinocembrin) and total flavones (apigenin and chrysin). Obtained results revealed that multifloral honey had more total flavonoids than acacia samples did. On average from all of the samples, multifloral honey had more of quercetin, hesperetin, luteolin, kaempferol and apigenin than acacia honey did. Content of flavonoids increased in samples between the 1st and 6th month of storage and then started to decrease until the 9th month, when they remained relatively constant all the way until the 12th month of storage. In conclusion, acacia and multifloral honey after one-year of storage still can be a valuable source of flavonoids. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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14 pages, 2447 KiB

Open AccessFeature PaperArticle

Application of Detrended Fluctuation Analysis and Yield Stability Index to Evaluate Near Infrared Spectra of Green and Roasted Coffee Samples

by Eszter Benes, Marietta Fodor, Sándor Kovács and Attila Gere

Processes 2020, 8(8), 913; https://doi.org/10.3390/pr8080913 - 1 Aug 2020

Cited by 8 | Viewed by 2847

Abstract

Coffee quality, and therefore its price, is determined by coffee species and varieties, geographic location, the method used to process green coffee beans, and particularly the care taken during coffee production. Determination of coffee quality is often done by the nondestructive and fast [...] Read more.

Coffee quality, and therefore its price, is determined by coffee species and varieties, geographic location, the method used to process green coffee beans, and particularly the care taken during coffee production. Determination of coffee quality is often done by the nondestructive and fast near infrared spectroscopy (NIRS), which provides a huge amount of data about the samples. NIRS data require sophisticated, multivariate data analysis methods, such as principal component analysis, or linear discriminant analysis. Since the obtained data are a set of spectra, they can also be analyzed by signal processing methods. In the present study, the applications of two novel methods, detrended fluctuation analysis (DFA) and yield stability index (YSI), is introduced on NIR spectra of different roasting levels of coffee samples. Fourteen green coffee samples from all over the world have been roasted on three different levels and their NIR spectra were analyzed. DFA successfully differentiated the green samples from the roasted ones, however, the joint analysis of all samples was not able to differentiate the roasting levels. On the other hand, DFA successfully differentiated the roasting levels on samples level, which was strengthened by a 100% accurate agglomerative hierarchical clustering. YSI was first used in NIR signal processing and was able to detect that a light roast is the most stable among all roasting levels. Future research should focus on the application of DFA in terms of the analysis of the effects of other transformation methods of the spectra. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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25 pages, 2905 KiB

Open AccessArticle

Production of Liquid Milk Protein Concentrate with Antioxidant Capacity, Angiotensin Converting Enzyme Inhibitory Activity, Antibacterial Activity, and Hypoallergenic Property by Membrane Filtration and Enzymatic Modification of Proteins

by Arijit Nath, Burak Atilla Eren, Attila Csighy, Klára Pásztorné-Huszár, Gabriella Kiskó, László Abrankó, Attila Tóth, Emőke Szerdahelyi, Zoltán Kovács, András Koris and Gyula Vatai

Processes 2020, 8(7), 871; https://doi.org/10.3390/pr8070871 - 18 Jul 2020

Cited by 9 | Viewed by 5669

Abstract

Liquid milk protein concentrate with different beneficial values was prepared by membrane filtration and enzymatic modification of proteins in a sequential way. In the first step, milk protein concentrate was produced from ultra-heat-treated skimmed milk by removing milk serum as permeate. A tubular [...] Read more.

Liquid milk protein concentrate with different beneficial values was prepared by membrane filtration and enzymatic modification of proteins in a sequential way. In the first step, milk protein concentrate was produced from ultra-heat-treated skimmed milk by removing milk serum as permeate. A tubular ceramic-made membrane with filtration area 5 × 10⁻³ m² and pore size 5 nm, placed in a cross-flow membrane house, was adopted. Superior operational strategy in filtration process was herein: trans-membrane pressure 3 bar, retention flow rate 100 L·h⁻¹, and implementation of a static turbulence promoter within the tubular membrane. Milk with concentrated proteins from retentate side was treated with the different concentrations of trypsin, ranging from 0.008–0.064 g·L⁻¹ in individual batch-mode operations at temperature 40 °C for 10 min. Subsequently, inactivation of trypsin in reaction was done at a temperature of 70 °C for 30 min of incubation. Antioxidant capacity in enzyme-treated liquid milk protein concentrate was measured with the Ferric reducing ability of plasma assay. The reduction of angiotensin converting enzyme activity by enzyme-treated liquid milk protein concentrate was measured with substrate (Abz-FRK(Dnp)-P) and recombinant angiotensin converting enzyme. The antibacterial activity of enzyme-treated liquid milk protein concentrate towards Bacillus cereus and Staphylococcus aureus was tested. Antioxidant capacity, anti-angiotensin converting enzyme activity, and antibacterial activity were increased with the increase of trypsin concentration in proteolytic reaction. Immune-reactive proteins in enzyme-treated liquid milk protein concentrate were identified with clinically proved milk positive pooled human serum and peroxidase-labelled anti-human Immunoglobulin E. The reduction of allergenicity in milk protein concentrate was enzyme dose-dependent. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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19 pages, 663 KiB

Open AccessFeature PaperArticle

Accelerated Solvent Extraction as a Green Tool for the Recovery of Polyphenols and Pigments from Wild Nettle Leaves

by Maja Repajić, Ena Cegledi, Valentina Kruk, Sandra Pedisić, Fırat Çınar, Danijela Bursać Kovačević, Ivanka Žutić and Verica Dragović-Uzelac

Processes 2020, 8(7), 803; https://doi.org/10.3390/pr8070803 - 9 Jul 2020

Cited by 48 | Viewed by 6033

Abstract

This study aimed to investigate the performance of accelerated solvent extraction (ASE) as a green approach for the recovery of polyphenols and pigments from wild nettle leaves (NL). ASE was operated at different temperatures (20, 50, 80 and 110 °C), static times (5 [...] Read more.

This study aimed to investigate the performance of accelerated solvent extraction (ASE) as a green approach for the recovery of polyphenols and pigments from wild nettle leaves (NL). ASE was operated at different temperatures (20, 50, 80 and 110 °C), static times (5 and 10 min) and cycle numbers (1–4) using ethanol (96%) as an extraction solvent. In order to compare the efficiency of ASE, ultrasound assisted extraction (UAE) at 80 °C for 30 min was performed as a referent. Polyphenol and pigment analyses were carried out by HPLC and antioxidant capacity was assessed by ORAC. Seven polyphenols from subclasses of hydroxycinnamic acids and flavonoids, along with chlorophylls a and b and their derivatives and six carotenoids and their derivatives were identified and quantified. Chlorogenic acid was the most abundant polyphenol and chlorophyll a represented the dominant pigment. ASE conditions at 110 °C/10 min/3 or 4 cycles proved to be the optimal for achieving the highest yields of analyzed compounds. In comparison with UAE, ASE showed better performance in terms of yields and antioxidants recovery, hence delivering extract with 60% higher antioxidant capacity. Finally, the potential of NL as a functional ingredient from natural sources can be successfully accessed by ASE. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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12 pages, 254 KiB

Open AccessFeature PaperArticle

Volatile Esters and Fusel Alcohol Concentrations in Beer Optimized by Modulation of Main Fermentation Parameters in an Industrial Plant

by Krzysztof Kucharczyk, Krzysztof Żyła and Tadeusz Tuszyński

Processes 2020, 8(7), 769; https://doi.org/10.3390/pr8070769 - 30 Jun 2020

Cited by 10 | Viewed by 4340

Abstract

Contents of selected volatile esters and fusel alcohols and their relation to the sensory quality of a bottom-fermented lager beer fermented under high-gravity conditions (15.5 °P) were analyzed using response surface methodology (RSM, Box–Behnken design). The influence of various pitching rates (6–10 mln [...] Read more.

Contents of selected volatile esters and fusel alcohols and their relation to the sensory quality of a bottom-fermented lager beer fermented under high-gravity conditions (15.5 °P) were analyzed using response surface methodology (RSM, Box–Behnken design). The influence of various pitching rates (6–10 mln cells/mL), aeration levels (8–12 mgO₂/mL), times (4.5–13.5 h) of filling CCTs (cylindroconical fermentation tanks; 3850 hL), and fermentation temperatures (8.5–11.5 °C) on the contents of selected esters, as well as on concentrations of amyl alcohols and on the sum of higher alcohols in beer, was determined in a commercial brewery fermentation plant. Beers produced throughout the experiments met or exceeded all criteria established for a commercial, marketed beer. Statistical analyses of the results revealed that within the studied ranges of process parameters, models with diversified significance described the concentrations of volatiles in beer. The multiple response optimization procedure analyses showed that the values of process parameters that minimized higher alcohols in beer (97.9 mg/L) and maximized its ethyl acetate (22.0 mg/L) and isoamyl acetate (2.09 mg/L) contents, as well as maximized the sensory quality of beer, (66.4 pts) were the following: Pitching rate 10 mln cells per mL; fermentation temperature 11.5 °C; aeration level 8.8 mg/L; and CCT filling time 4.5 h. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

10 pages, 2153 KiB

Open AccessFeature PaperArticle

Heterotrophic Plate Count for Bottled Water Safety Management

by Anna Rygala, Joanna Berlowska and Dorota Kregiel

Processes 2020, 8(6), 739; https://doi.org/10.3390/pr8060739 - 24 Jun 2020

Cited by 10 | Viewed by 8711

Abstract

Heterotrophic bacteria are able to form biofilms in water processing systems, adhering to pipe materials and colonizing surfaces. The aim of our research was to identify the critical points in the process of bottled water production at which controls can be applied to [...] Read more.

Heterotrophic bacteria are able to form biofilms in water processing systems, adhering to pipe materials and colonizing surfaces. The aim of our research was to identify the critical points in the process of bottled water production at which controls can be applied to prevent, reduce, or eliminate water safety hazards. Microbiological monitoring was conducted using the plate count method and luminometry. To identify the bacterial isolates, we used polyphasic identification based on biochemical tests and molecular analysis using ribosomal RNA. The heterotrophic plate counts were higher in the water filtration station, ultrafiltration (UV) disinfection station, and holding tank. At these points of the industrial process, the water is stagnant or there is poor flow. Molecular analysis identified the bacterial isolates as belonging to Acinetobacter, Agrobacterium, Aeromonas, Brevundimonas, Citrobacter, Enterobacter, Klebsiella, Pantoea, and Rhizobium genera. Bacterial isolates showed various levels of biofilm formation, and the best adhesion properties were exhibited by the Aeromonas hydrophila and Citrobacter freundii strains. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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13 pages, 2154 KiB

Open AccessArticle

A Deep Learning Method for Yogurt Preferences Prediction Using Sensory Attributes

by Kexin Bi, Tong Qiu and Yizhen Huang

Processes 2020, 8(5), 518; https://doi.org/10.3390/pr8050518 - 27 Apr 2020

Cited by 17 | Viewed by 4355

Abstract

During the development of innovative products, consumer preferences are the essential factors for yogurt producers to improve their market share. A high-performance prediction method will be beneficial to understand the intrinsic relevance between preferences and sensory attributes. In this study, a novel deep [...] Read more.

During the development of innovative products, consumer preferences are the essential factors for yogurt producers to improve their market share. A high-performance prediction method will be beneficial to understand the intrinsic relevance between preferences and sensory attributes. In this study, a novel deep learning method is proposed that uses an autoencoder to extract product features from the sensory attributes scored by experts, and the sensory features acquired are regressed on consumer preferences with support vector machine analysis. Model performance analysis, hedonic contour mapping, and feature clustering were implemented to validate the overall learning process. The results showed that the deep learning model can vouch an acceptable level of accuracy, and the hedonic mapping reflected could supply a great help for producers’ product design or modification. Finally, hierarchical clustering analysis revealed that for all three brands of yogurts, low temperature (4 °C) storage for no more than 4 weeks can promise the highest consumer preferences. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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Review

Jump to: Editorial, Research

21 pages, 1696 KiB

Open AccessFeature PaperReview

Effect of Selected Drying Methods and Emerging Drying Intensification Technologies on the Quality of Dried Fruit: A Review

by Milivoj Radojčin, Ivan Pavkov, Danijela Bursać Kovačević, Predrag Putnik, Artur Wiktor, Zoran Stamenković, Krstan Kešelj and Attila Gere

Processes 2021, 9(1), 132; https://doi.org/10.3390/pr9010132 - 9 Jan 2021

Cited by 66 | Viewed by 16298

Abstract

Drying is one of the oldest methods for food preservation that removes the water from fruit and makes it available for consumption throughout the year. Dried fruits can be produced by small- and large-scale processors, which makes them a very popular food among [...] Read more.

Drying is one of the oldest methods for food preservation that removes the water from fruit and makes it available for consumption throughout the year. Dried fruits can be produced by small- and large-scale processors, which makes them a very popular food among consumers and food manufacturers. The most frequent uses of drying technology include osmotic dehydration, vacuum drying, freeze-drying and different combinations of other drying technologies. However, drying may provoke undesirable changes with respect to physiochemical, sensory, nutritional and microbiological quality. Drying process energy efficiency and the quality of dried fruits are crucial factors in fruit drying. Recently, innovative technologies such as ultrasound, pulsed electric field and high pressure may be used as a pretreatment or in combination with traditional drying technologies for process intensification. This could result in quality improvements of dried fruits and enhanced efficiency and capacity of the production process, with a positive impact on environmental and economic benefits. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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16 pages, 717 KiB

Open AccessReview

Modifying Effects of Physical Processes on Starch and Dietary Fiber Content of Foodstuffs

by Róbert Nagy, Endre Máthé, János Csapó and Péter Sipos

Processes 2021, 9(1), 17; https://doi.org/10.3390/pr9010017 - 23 Dec 2020

Cited by 18 | Viewed by 5800

Abstract

Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key [...] Read more.

Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key issues of food processing is how to influence the technological and nutritional properties of carbohydrates to meet modern dietary requirements more effectively, considering particularly the trends in the behavior of people and food-related health issues. Physical processing methods have several advantages compared to the chemical methods, where chemical reagents, such as acids or enzymes, are used for the modification of components. Furthermore, in most cases, these is no need to apply them supplementarily in the technology, only a moderate modification of current technology can result in significant changes in dietary properties. This review summarizes the novel results about the nutritional and technological effects of physical food processing influencing the starch and dietary fiber content of plant-derived foodstuffs. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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13 pages, 785 KiB

Open AccessReview

Magnetic Fields in Food Processing Perspectives, Applications and Action Models

by Hubert Luzdemio Arteaga Miñano, Ana Carolina de Sousa Silva, Sergio Souto and Ernane José Xavier Costa

Processes 2020, 8(7), 814; https://doi.org/10.3390/pr8070814 - 10 Jul 2020

Cited by 43 | Viewed by 12724

Abstract

Magnetic fields (MF) are increasingly being applied in food processing to preserve food quality. They can be static (SMF), oscillating (OMF) or pulsed (PMF) depending on the type of equipment. The food characteristics can be influenced by several configurations of the applied magnetic [...] Read more.

Magnetic fields (MF) are increasingly being applied in food processing to preserve food quality. They can be static (SMF), oscillating (OMF) or pulsed (PMF) depending on the type of equipment. The food characteristics can be influenced by several configurations of the applied magnetic field as its flux density, frequency, polarity and exposure time. Several mechanisms have been proposed to explain the effects of magnetic fields on foods. Some of them propose interactions at the subatomic particle level that show quantum behavior, such as the radical pair and cyclotron resonance mechanisms. Other proposals are at the level of DNA, compounds, subcellular organelles and cells. The interactions between food and magnetic fields are addressed in a general way in this work, highlighting the applications and action models involved and their effects on the physicochemical, enzymatic and microbiological characteristics of food. Full article

(This article belongs to the Special Issue Processing Foods: Process Optimization and Quality Assessment)

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