What are the challenges for ohmic heating in the food industry? Insights of a bibliometric analysis.

The trends related to ohmic heating technology in food processing were evaluated using bibliometric analysis based on the scientific literature published in the last decade. Publications from Turkey, Brazil, and Iran represent 32% of all publications. Most studies have targeted the definition of the best combinations of operational parameters for application in different food matrices and their possible effects on the food properties. In addition, a tendency to use ohmic heating as an alternative technology for pasteurization was observed. Future studies should develop mathematical models that evaluate process parameters and food characteristics in the inactivation of microorganisms and enzymes and maintenance of bioactive compounds, the study of the non-thermal effect of electromagnetic waves on the food quality, the evaluation of the processing conditions and food physicochemical properties in the electrode corrosion and migration of metal ions to the treated food, and improvements of homogeneity during processing. This study was the first to perform a bibliometric analysis based on scientific literature concerning ohmic heating in food processing and presented the challenges, future trends, and evolution of scientific research.

In vitro viability of L. Casei B-442 and fructooligosaccharides integrity in Amazonian sapota-do-solimões functional juice.

Sapota-do-solimões (Quararibea cordata) juice was fermented by Lacticaseibacillus casei B-442 to produce a probiotic and a synbiotic juice. The synbiotic juice was obtained by adding fructooligosaccharides (FOS, 7%, w/v). After the fermentation (37 °C by 15 h) the L. casei viability was above 11 log CFU/mL in both juices. The microbial survival rate after 30 days of cold storage (4 °C) was higher in probiotic juice (97%) than in prebiotic juice (82%). The effect of fermentation and the food matrix on L. casei viability was assessed by the simulated digestion at the beginning and the end of cold storage (4 °C for 30 days). After the simulated digestion, the probiotic counts were above 8 log CFU/mL in synbiotic juice and above 4 log CFU/mL in probiotic juice. The main L. casei metabolites produced in the sapota-dos-solimões juice were lactic acid and acetic acid. Isobutyric, and propionic acids presented higher production in synbiotic juice compared to the probiotic juice. No FOS hydrolysis was observed during the storage or the simulated digestion. L. casei did not consume FOS as carbon source. Thus, sapota-do-solimões juice is an exotic suitable non-dairy-based matrix for functional beverages.

Development of alginate/inulin carrier systems containing non-conventional Amazonian berry extracts.

Different carriers, such as the combination of sodium alginate and inulin, have been employed to protect foods against environmental effects. The goal of this work was to use the ionic gelation encapsulation process to produce microparticles containing Clidemia rubra extract, ranging the concentration of inulin from 1.5 to 3.5 g inulin.100 g-1 of solution. Characteristic signals of sugars, organic acids and phenolic compounds were identified in the extract using the 1H NMR technique. The carriers containing inulin presented significant difference in the moisture content when compared to the pure sodium alginate beads. The produced beads were found in the range of 0.81-1.06 mm. The addition of inulin to sodium alginate was significant for the encapsulation efficiency (EE) of the antioxidant compounds when compared to the beads formed only using pure sodium alginate. The microspheres presenting inulin and sodium alginate presented higher content of spherical particles. The addition of 2.5 g inulin.100 g-1 of solution allowed its incorporation into the pores of the beads, favoring a possible chemical interaction between inulin and sodium alginate. This interaction resulted in a different crystal structure and better EE. Furthermore, beads containing inulin presented higher protection of the encapsulated bioactive compounds during the gastric phase.

Potential use of vegetable proteins to reduce Brazil nut oil oxidation in microparticle systems.

Brazil nut oil is mostly composed of unsaturated fatty acids, some of which are associated with decreased incidence of cardiovascular diseases. Vegetable proteins have been increasingly used as wall material for partial replacement of carbohydrates and whey proteins. In order to create an oil preservation method, Brazil nut oil was encapsulated with three different types of vegetable protein concentrates and gum arabic (GA): rice (RPC + GA); pea (PPC + GA); and soy (SPC + GA) .For this purpose, vegetable protein concentrates were characterized, and after the drying process the physicochemical characteristics of the microparticles were evaluated. The most stable emulsion, after seven days of evaluation, was composed of RPC + GA. RPC + GA. This treatment was also more stable based on the shelf life assessments. We concluded that RCP microparticles were the best option for encapsulating Brazil nut oil in comparison with the other particles evaluated. In addition, the product obtained is potentially capable of being included in various processed foods.

Encapsulation of camu-camu extracts using prebiotic biopolymers: Controlled release of bioactive compounds and effect on their physicochemical and thermal properties.

Camu-camu (Myrciaria dubia [H.B.K] McVaugh) is a Amazonian fruit rich in ascorbic acid and phenolic compounds, and has been attracting great interest from the food, pharmaceutical and nutraceutical industries due to its potential health benefits. The bioactive compounds from camu-camu are considered sensitive and unstable, resulting in nutritional losses and impairment of its commercialization and export. For this reason, the camu-camu extract (pulp and peel) was subjected to microencapsulation by spray drying process using maltodextrin (MD), inulin (IN), and oligofructose (OL) as carrier agents. Lyophilized in natura camu-camu extract (CEL) was also evaluated. Thus, physicochemical and thermal properties and controlled release at different temperatures (25 °C and 35 °C) were investigated. In contrast with the IN and OL microparticles, the MD microparticles showed lower density and hygroscopicity, besides greater thermal stability, antioxidant activity, and retention of ascorbic acid and anthocyanins. FTIR spectra allowed the qualitative evidence of encapsulation of the bioactive compounds from the camu-camu extract. The highest percentage of volatile compounds was observed in IN microparticles, followed by OL and MD microparticles. The major group of compounds identified in CEL were terpenes (88%). The Korsmeyer-Peppas mathematical model allowed to describe the controlled release behavior of ascorbic acid and anthocyanins in the powder extracts. The controlled release followed a Fickian diffusion mechanism (n ≤ 0.43). The increase of temperature from 25 °C to 35 °C influenced on the release of bioactive compounds in all treatments, showing greater release for MD microparticles. The encapsulating materials were considered effective for the production of camu-camu extract powder, contributing to the better use of this Amazonian fruit. In addition, the encapsulation process increased the stability of its bioactive compounds, representing a tool to facilitate their incorporation in several matrices to act as antioxidant and coloring agents, as well as nutraceutical.