Insight into High-Hydrostatic Pressure Extraction of Polyphenols from Tomato Peel Waste.

In this paper, high-hydrostatic pressure extraction (HHPE) as an emerging food processing and preservation technique constitutes an alternative to conventional thermal treatment that has been used for extraction of polyphenols from tomato peel waste generated by the canning industry. The impact of time (5 and 10 min), temperature (25, 35, 45 and 55 °C) and solvents (water, 1% HCl, 50 and 70% methanol with and without addition of HCl, and 50 and 70% ethanol), at a constant pressure of 600 MPa, has been evaluated in this paper with respect to polyphenols' yields. The results showed a significant (p < 0.05) variation in the contents of a great number of phenolic compounds in respect of the applied temperatures and solvents. On the other hand, the time invested in HHPE had no effect on polyphenols' yields. Among phenolic compounds, the p-coumaric acid (p-CA) and chlorogenic acid derivative (ChA der) are predominant, i.e., 0.57 to 67.41 mg/kg and 1.29 to 58.57 mg/kg, respectively, depending on the solvents and temperatures used. In particular, methanol (50 and 70%) at temperatures of 45 and 55 °C enhanced the recovery of polyphenols in comparison to other utilised solvents. In conclusion, this paper puts forth the theory that by applying HHPE with minimal expenditure of time, it is possible to achieve efficient production of polyphenols from low-cost tomato peel waste, generating income both for producers and agri-food industries.

Novel Approach to the Development of Functional Goat's Milk-Based Beverages Using Medicinal Plant Extracts in Combination with High Intensity Ultrasound Treatment.

Regardless of its highly valuable nutritive composition, goat's milk is less preferred by consumers due to its specific sensory characteristics that are very often regarded as undesirable. On the other hand, traditional medicinal plants from Lamiaceae family, due to their rich bioactive composition, especially polyphenols, and desirable aroma profile, can be used to enhance and improve bioactive and sensory properties of food. In the present study nutritively valuable beverages were produced by enrichment of goat's milk with medicinal plant extracts derived from the Lamiaceae family and stabilized by homogenization with high intensity ultrasound treatment. The impact of plant species (lemon balm, mint, lavender, rosemary and sage) and ultrasound treatment duration (5 or 10 min) on the physicochemical, bioactive and sensory characteristics of enriched beverages was evaluated. The addition of plant extracts to goat's milk significantly increased the concentration of bioactive components (rosmarinic acid, hydroxycinnamic acid derivatives and luteolin derivatives), in dependence of the added plant extract. The prolongation of the ultrasound homogenization markedly decreased the fat globule size and thus beneficially affected the product stability. Apart from the achieved bioactive enrichment and stability, the developed beverages exhibited significantly improved sensory properties in comparison to plain goat's milk, with the highest overall acceptability determined for samples enriched with mint and rosemary.

Characterization of Antioxidant Bioactive Compounds and Rheological, Color and Sensory Properties in 3D-Printed Fruit Snacks.

The influence of wheat starch (6%, 8% and 10%, w/w) and a 3D printing program (program 1 vs. program 2) on the content of bioactive compounds, antioxidant capacity, color parameters and rheological and sensory properties was investigated in 3D strawberry and strawberry tree fruit snacks. Increasing the starch content led to a decrease in the content of almost all the bioactive compounds, while it had no effect on the antioxidant capacity. The printing program had no significant effect on the bioactive compounds (except hydroxycinnamic acids), antioxidant capacity and color parameters. A higher starch content improved the strength of the sample but had no effect on the mechanical properties. Smaller particles with a higher starch content improved the stability of the sample. In contrast to the programs, varying the starch content had a significant effect on all the color parameters except the a* values. Eight different sweeteners in two different concentrations were used for the sensory evaluation of the 3D-printed snacks. The variations in sweetener content only affected the sweet and harmonious taste. In summary, this study confirms the great potential of fruit bases for the production of 3D-printed snacks with excellent biological and rheological properties, which can be a step toward personalized food with the addition of sweeteners.

3D Printing of Functional Strawberry Snacks: Food Design, Texture, Antioxidant Bioactive Compounds, and Microbial Stability.

3D printing technology (3DP) as additive manufacturing is an innovative design technology that can meet the individual nutritional and sensory needs of consumers. Therefore, the aim of this work was to apply 3DP in the production of a strawberry-based functional product with the addition of two hydrocolloids (corn and wheat starch) in three proportions (10, 15 and 20%) and to investigate the influence of 3DP process parameters on physico-chemical and textural properties, as well as the bioactive and antioxidant potential and microbiological stability, with(out) the addition of natural antimicrobial agents. Starch type had a significant effect on all tested bioactive compounds, as well as on starch content, except for total phenolic and hydroxycinnamic acid contents. Considering the content of bioactive compounds and antioxidant capacity, program 2 proved to be more suitable than program 1. All samples exhibited good textural properties, a high degree of stability and minimal geometric deviations. Regarding microbiological safety, no pathogenic bacteria were found in the 3DP samples during storage. The 3DP sample with added citral at a concentration of 75 mg L-1 showed the best microbiological quality. Ultimately, 3DP can be successfully used for the production of new strawberry-based functional products.

Non-Thermal Ultrasonic Extraction of Polyphenolic Compounds from Red Wine Lees.

This study presents the results of conventional aqueous (CE) and non-conventional ultrasound-assisted (UAE) extractions of polyphenolic compounds from lees extracts of red wine varieties (Merlot and Vranac). The effect of ultrasound extraction time (t, s), and amplitude (A,%) from a 400 W ultrasound processor with different ultrasonic probes diameters (Ds, mm) on the amount and profile of polyphenolic compounds in the obtained extracts was investigated and compared to CE. The optimal conditions resulting in maximum extraction of phenolic compounds were: Probe diameter of 22 mm, amplitude 90% and extraction time for Vranac wine lees 1500 s and for Merlot wine lees extraction time of 1361 s. UAE proved to be significantly more effective in enhancing the extraction capacity of trans-resveratrol glucoside (30.57% to 300%), trans-resveratrol (36.36% to 45.75%), quercetin (39.94% to 43.83%), kaempferol (65.13% to 72.73%), petunidin-3-glucoside (41.53% to 64.95%), malvidin-3-glucoside (47.63% to 89.17%), malvidin-3-(6-O-acetyl) glucoside (23.84% to 49.74%), and malvidin-3-(6-O-p-coumaroyl) glucoside (26.77% to 34.93%) as compared to CE. Ultrasound reduced the extraction time (2.5-fold) and showed an increase of antioxidant potential by 76.39% (DPPH) and 125.83% (FRAP) compared to CE.

Influence of Carob Flour and Carob Bean Gum on Rheological Properties of Cocoa and Carob Pastry Fillings.

The aim of this study was to develop a new cocoa and carob based pastry filling and explore the influences of carob flour and carob gum on the rheological and textural properties, specifically (i) the effect of increasing the amount of carob flour and (ii) the effect of carob bean gum naturally present in the carob flour with seeds versus the commercially available carob bean gum. All samples analyzed in this study exhibited shear thinning behavior. The texture analysis revealed a significant (p < 0.01) increase in consistency and firmness in samples with higher amounts of carob flour added, while higher temperatures significantly (p < 0.01) decreased adhesiveness. When comparing naturally occurring and commercially available LBG (locust bean gum), it was concluded that lower concentrations (up to 0.45% w/w) of naturally occurring LBG work just as well at the same concentrations of commercially available LBG, but this effect cannot be confirmed for higher LBG concentrations, nor for rheological properties determined at higher temperatures (80 °C).

Comparison of Two pH Responsive Color Changing Bio-Based Films Containing Wasted Fruit Pomace as a Source of Colorants.

The main objective of this work is to develop and characterize novel bio-based sensor as intelligent food packaging film to monitor quality changes in fresh chicken meat. Chitosan (CS) and carboxymethyl cellulose (CMC) were used as polymer matrices for immobilization of pH sensitive color indicators. Generally considered as a food waste, blueberry (BP) and red grape skin pomace (RP) extracts were used as indicators at total phenolic content (TPC) of 0.06, 0.13, and 0.25 w/v for BP, and 0.006, 0.012, and 0.02 w/v for RP-based films. Color, mechanical, and intelligent material properties were determined. CS films were more elastic than CMC, while no significant changes in mechanical properties occurred after the addition of both extracts at all concentrations. Notable and eye recognizable color changes in dry films were seen. It was the most significant in the pH range from 4 to 7. For CMC-based films, color changed from violet to pink for BP extracts and from red to pink for RP extracts. For CS films, the changes were less significant. The color taint and intensity changed toward green in blueberry-based films and to orange in grape seed extract-based films. Significant color changes were observed after 46 hr in application tests on fresh chicken meat. This was correlated to pH changes of meat above 6 that was one of the parameters considered as an indication of spoilage. PRACTICAL APPLICATION: This work provides interesting data to food industry. It offers an idea and possibility of managing food waste from fruits and vegetables industry that makes problems and costs when needed to be disposed in a proper manner. Moreover, there is the possibility of producing novel kind of food packaging materials that could be used in order to check the end of food shelf-life in an inexpensive and natural way. Additional value lies in the fact that materials and procedures could be considered as sustainable.

Comparing the effects of thermal and non-thermal technologies on pomegranate juice quality: A review.

The consumption of pomegranate juice (PJ) has increased substantially since scientific literature reported its therapeutic benefits that are attributable to antioxidant, antimicrobial, anti-carcinogenic, and anti-inflammatory properties. The growing consumer demands for fresh and high-quality food products have led to the interest in non-thermal technologies for preservation of fruit juices. Although thermal pasteurization is the most widely used preservation technology, it has adverse effects on the nutritional and sensory quality of juices. Conversely, non-thermal technologies are suitable alternatives for preservation and without negative effects on the quality. However, there is limited scientific literature concerning the use of non-thermal technologies for preservation of PJ. Therefore, this review focuses on PJ preservation by using non-thermal technologies. In conclusion, pomegranate is an economical crop that can justify the use of advanced non-thermal technologies for PJ preservation, as consumers' interest can offset the expenses associated with investments in alternative technological options and processing adjustments.