Effect of apple fibre addition and temperature on the rheological properties of apple juice and compensation study

Rheology of liquid foods under shear flow conditions: Recently used models

Proper modeling of flow or viscosity curves as a function of shear rate is a useful tool in any engineering activity. The rheology of foods depends on the composition, processing to which they have been subjected and the state of dispersion in which they are found. Liquid foods are complex biosystems, that show non-Newtonian behavior under flow conditions. This review presents models used in recent decades to describe the experimental rheological behavior of various liquid foods, ranging from Newtonian fluids to the most complex. Some non-Newtonian parameters such as those of the Ostwald-de Waele, Bingham, Herschel-Bulkley, Casson, Cross, and Carreau models are summarized. Examples of thixotropic behavior described by the Weltman and Abu-Jdayil models are also presented. In each model, explanations based on the composition and dispersion state of the food are made. This is useful in innovative processing technologies and for scientists new to the field of food rheology. An attempt is made to exemplify and group the expected behavior for most fluid foods, including some for a dysphagia diet, depending on their composition or the dispersed system formed, which will be useful for professionals who wish to compare reported rheological parameters with those obtained experimentally.

Formulation, Characterization, and Determination of the Rheological Profile of Loquat Compote Mespilus Germánica L. through Sustenance Artificial Intelligence

The theme of the presented study is to create a compote that is functional, inexpensive in cost, free of preservatives, and will have long shelf life, as well as to assess its rheological, sensory, and physicochemical properties. The objective was to construct a loquat compote (Mespilus germánica L.) using agar from cochayuyo (Chondracanthus chamissoi) for infants, determining its rheological profile with the addition of agar extracted from cochayuyo in three concentrations (0.10, 0.15, and 0.20) % w/w, respectively, with help of artificial intelligence (AI) pathway. Agar was withdrawn from the cochayuyo by alkaline treatment with 0.04 M NaOH, obtaining a yield of 1%. Consequently, each compote was subjected to a sensory attributes using a 5-point hedonic scale with 60 panelists (30 undergraduate students and 30 infants between 3 and 5 years of age using a graphic hedonic scale). The sensory analysis using AI as a base is applied to both adult and infant panelists determined that the compote that had as input agar from cochayuyo at a concentration of 15% had greater acceptability due to the fact that significance was reported ( $p<0.05$ ) according to Friedman’s test. The compote with the highest acceptability was subjected to proximal chemical characterization, reporting the following: moisture (64%), protein (1.68%), fat (1.01%), fiber (2.35%), ash (1.34%), and carbohydrates (29.62%). Its physicochemical characterization was also determined, reporting the following: pH (4.32), soluble solids (16° Brix), and total acidity (0.23 g malic acid/100 g compote). Finally, A Brookfield RV-DVIII ULTRA viscometer with Spindles N° 5 and 6 was used to integrate AI data gathering and use it for rheological profile assessment. The loquat compote was found to have a non-Newtonian, pseudoplastic behavior that was adjusted to the Ostwald–De Waele model with an R2 = 0.987.

Development of a Novel Low-Calorie Lime Juice-Based Prebiotic Beverage Using a Combined Design Optimization Methodology

A novel lime-juice based low-calorie functional beverage was developed by using D-optimal combined design optimization. For the preparation of the beverage, the following functional ingredients were used: lime juice, lime peel essential oil (LEO) as a flavoring agent and bioactive component, sucralose as a low-calorie sweetener, an inulin/polydextrose (I/P) mixture as prebiotic fibers, pectin as a thickening agent and soluble dietary fiber, lutein as a carotenoid colorant and antioxidant, and peppermint extract (ME) as a flavoring agent and bioactive component. A combined design consisting of one mixture factor (LEO/ME ratio), one numeric factor (lutein concentration), and one categoric factor (presence or absence of prebiotics) was used for optimizing the functional beverage based on the sensory quality. Regression models were adequately fitted to the data of sensory acceptance with a determination coefficient >90%. The sample containing a mixture of prebiotics, 2:3 (v/v) ratio of LEO: ME, and 3 mg/100 mL lutein was selected as the best formulation among the six optimal beverages which was suggested by Design-Expert software. This final optimum sample showed the highest total phenolic (44.22 mg gallic acid equivalents/L) and flavonoid (25.49 mg quercetin equivalents/L) contents, and its antioxidant activity (as 2,2-diphenyl-1-picrylhydrazyl radical (DPPH^•) scavenging) was 38.30%. The newly designed beverage has the potential to promote health benefits and in therapeutic applications.

Effect of ascorbic acid and acerola juice on some quality properties of aseptic filled apple juice

Quality and storability are crucial factors in production of apple juice. The main goal of this study was investigation of the effects of ascorbic acid and acerola juice on the changes of some sensorial parameters and bioactive compounds of aseptically filled and industrial scale produced apple juice during storage for 12 months. While the viscosity and pH of apple juice did not change significantly, the ΔE* peaked (20–30) at month 6 of the storage period. The colour of apple juice was lighter than at the beginning of storage. Maximum total phenolic contents were 1,100, 1,400, and 1,250 mg L−1 in the control, ascorbic acid supplemented, and acerola added samples, respectively. Other parameters (antioxidant capacity, ascorbic acid, browning index, etc.) peaked in month 4. Acerola was a good alternative anti-browning and antioxidant agent for the treatment of apple juice in the processing. The antioxidant capacity of apple juice treated with acerola was higher than with ascorbic acid. The results were obtained with industrial samples, thus, they can serve as a very good base for the optimisation process and industrial production without the need for scale-up.

Determination of the rheological behavior and thermophysical properties of malbec grape juice concentrates (Vitis vinifera)

The rheological behavior and thermophysical properties (density, specific heat, and thermal conductivity) were experimentally determined as function of temperature (1-66 °C) and solid soluble content (13.6-45.0°Brix) for Malbec grape juice aiming at designing the unit operations involved in beverage industries. Mathematical modeling was performed to provide valuable information about the rheological behavior and thermophysical properties of Malbec grape juice at different concentrations and temperatures. The Ostwald-de Waele model fitted the concentrates rheological behavior with high accuracy. The consistency coefficients were significantly reduced by the temperature increase, following an Arrhenius relationship with activation energy ranging from 11.02 kJ/mol (45.0 °Brix) to 11.54 kJ/mol (21.0 °Brix). In contrast, they were increased by the higher concentration levels, ranging from 0.2044 Pa.sⁿ (13.6 °Brix, 6 °C) to 20.9451 Pa.sⁿ (45.0 °Brix, 1 °C). The flow behavior index was not influenced by temperature; however, it was strictly related to the concentration, assuming shear-thinning behavior (0.96 < n < 0.54), regardless of the solid soluble contents. Density, specific heat, and thermal conductivity were significantly correlated with both the temperature and concentration parameters by second-order polynomial models. The obtained results can be suitable for the potential use of Malbec juice concentrate as a chaptalization agent in winemaking and grape juice production.