C.E. Ochoa-Velasco

Ultraviolet-C light effect on physicochemical, bioactive, microbiological, and sensorial characteristics of carrot (Daucus carota) beverages

The aim of this research was to evaluate the effect of ultraviolet-C light on physicochemical, bioactive, microbial, and sensory characteristics of carrot beverages. Beverages were formulated with different concentrations of carrot juice (60, 80, and 100% [v/v]) and treated with ultraviolet-C light at different flow rates (0, 0.5, 3.9, and 7.9 mL s−1) and times (5, 10, 15, 20, and 30 min), equivalent to ultraviolet-C dosages of 13.2, 26.4, 39.6, 52.8, and 79.2 J cm−2. Total soluble solids, pH, and titratable acidity were not affected by the ultraviolet-C light treatment. Ultraviolet-C light significantly affected (p < 0.05) color parameters of pure juice; however, at low concentration of juice, total color change was slightly affected (ΔE = 2.0 ± 0.7). Phenolic compounds (4.1 ± 0.1, 5.2 ± 0.2, and 8.6 ± 0.3 mg of GAE 100 mL−1 of beverage with 60, 80, and 100% of juice, respectively) and antioxidant capacity (6.1 ± 0.4, 8.5 ± 0.4, and 9.4 ± 0.3 mg of Trolox 100 mL−1 of beverage with 60, 80, and 100% of juice, respectively) of carrot beverages were not affected by ultraviolet-C light treatment. Microbial kinetics showed that mesophiles were mostly reduced at high flow rates in carrot beverages with 60% of juice. Maximum logarithmic reductions for mesophiles and total coliforms were 3.2 ± 0.1 and 2.6 ± 0.1, respectively, after 30 min of ultraviolet-C light processing. Beverages were well accepted (6–7) by judges who did not perceive the difference between untreated and Ultraviolet-C light treated beverages.

Growth modeling to control ( in vitro ) Fusarium verticillioides and Rhizopus stolonifer with thymol and carvacrol

The aim of this study was to evaluate the antifungal activity (in vitro) of thymol and carvacrol alone or in mixtures against Fusarium verticillioides and Rhizopus stolonifer, and to obtain primary growth models. Minimal inhibitory concentration (MIC) was evaluated with fungal radial growth with thymol or carvacrol concentrations (0-1600mg/l). Mixtures were evaluated using concentrations below MIC values. Radial growth curves were described by the modified Gompertz equation. MIC values of carvacrol were 200mg/l for both fungi. Meanwhile, MIC values of thymol were between 500 and 400mg/l for F. verticillioides and R. stolonifer, respectively. A synergistic effect below MIC concentrations for carvacrol (100mg/l) and thymol (100-375mg/l) was observed. Significant differences (p<0.05) between the Gompertz parameters for the antimicrobial concentrations and their tested mixtures established an inverse relationship between antimicrobial concentration and mycelial development of both fungi. Modified Gompertz parameters can be useful to determine fungistatic concentrations.

Chapter 47 – Combinational Approaches for Antimicrobial Packaging: Chitosan and Oregano Oil

Abstract The aim of this chapter is to present recent advances regarding chitosan and oregano essential oil as well as approaches of their combination for antimicrobial packaging. Materials currently utilized for the manufacture of food packaging can be replaced by biopolymers (including chitosan) because some of their properties are similar to those of synthetic polymers. Furthermore, there could be mixtures of different biopolymers or mixtures thereof with synthetic polymers; selection of mixtures depends on needed application and type of food product to be packaged. Barrier properties (water vapor, oxygen, and carbon dioxide permeability) and mechanical properties (tensile strength and elongation) will determine the feasibility of formed films to meet desired functionality for the product to be packed. Chitosan is, after cellulose, one of the most abundant biopolymers in nature, with antimicrobial, antioxidant, and antiviral properties. When combined with oregano essential oil that has antimicrobial and antioxidant activities, it may produce effective edible films and packaging materials.

Phenolic Compounds: A Good Choice Against Chronic Degenerative Diseases

Abstract Phenolic compounds are a group of metabolites derived from the secondary pathways of plants. Polyphenols comprise flavonoids, phenolic acids, tannins, lignans, and coumarins, compounds naturally found in fruits, vegetables, cereals, roots, and leaves among other plant products. In this sense, recent works suggest the potential health benefits of phenolic compounds as antioxidants against oxidative stress diseases. In the last few decades, the chronic degenerative diseases, such as atherosclerosis, hypertension, types of cancers, diabetes mellitus, and obesity among others, have increased. In this regard, several evidences suggest that many of these disorders are related to the consumption of processed foods; fortunately, the tendency is changing to consume raw or unprocessed foods. Therefore, the aim of this chapter is to present an extended revision of the properties of phenolic compounds produced in plants and their effects against several chronic degenerative diseases. Besides the continuously consumption of the phenolic compounds can improve the human health or help in the prevention of different illnesses.

Figo da india— Opuntia spp.

Abstract Prickly pear, cactus pear or “tuna” is the fruit of the cactus pads tree (Opuntia spp.) or “nopal” member of the Cactaceae family. There are a number of prickly pears with a wide range of flavors and colors. Prickly pears are known with different scientific names (Opuntia spp.) and common names, depending on the interior and exterior colors, size, and region of production. Pale-green, yellow, orange, magenta, red, and red–purple are the color of prickly pear pulp. Prickly pear is produced in Summer over a very short period of time. Fresh fruits do not last too long, even stored at refrigeration conditions. Today, the fruit is eaten fresh or as juice, chilled or at room temperature; however, there are some locally manufactured products such as preserves, prickly pear fudge, crystallized prickly pear, and prickly pear wine in some villages or towns where the fruit is grown. However, there are a number of Opuntia spp. prickly pears that grows in nature that are not consumed.

Effect of pH and Mexican Oregano (Lippia berlandieri Schauer) Essential Oil Added to Carboxymethyl Cellulose and Starch Edible Films on Listeria monocytogenes and Staphylococcus aureus

The aim of this work was to evaluate the effect of pH and Mexican oregano essential oil (MOEO) added to carboxymethyl cellulose (CMC) and starch (S) edible films on Listeria monocytogenes and Staphylococcus aureus. CMC and S edible films were formulated with different concentrations (0%, 0.25%, 0.50%, 0.75%, and 1%) of MOEO at different pH (5, 6, or 7). Antimicrobial assay was performed. Inhibition curves were fitted to the Fermi model. Significant differences ( ) were found in tc (time to reduce 50% of microbial population) and (slope of the curve around ), being lower at acidic pH. For L. monocytogenes, CMC films exhibited a higher antimicrobial effectiveness (0.50% of MOEO) compared to S films which need a higher concentration of MOEO (0.75%). S. aureus was inhibited with CMC films at 0.50% MOEO and pH 5 and 6. Microbial modeling has allowed estimating key intrinsic factors as pH and MOEO concentration with the synergistic effect against two important food-borne pathogens.

Use of microbial models to evaluate the effect of UV-C light and trans-cinnamaldehyde on the native microbial load of grapefruit (Citrus × paradisi) juice

The aim of this research was to evaluate the storage stability (5 °C), and microbial modeling, of Rubi red grapefruit (Citrus × paradisi) juice treated with ultraviolet-C (UV-C) light (0, 10 and 20 min), alone or in combination with trans-cinnamaldehyde (trans-CAH) (0, 25 and 50 μg/mL). A 32 factorial design was used and data modeled with the Weibull, Modified Gompertz and Logistic models. A response surface model was used to evaluate the effect of modeling parameters for suggesting the optimum treatment conditions. Treated and some untreated juice lasted up to 9 days without physicochemical and microbial changes. At the higher combination of UV-C light and trans-CAH, the microbial load of grapefruit juice was maintained below 100 CFU/mL up to 15 days. For mesophiles, the three predictive models indicated that the parameters n and Nmax decreased and the parameters λ and tc increased as the combination of UV-C light and trans-CAH increased. The response surface modeling of the parameters obtained by the predictive models showed acceptable correlation for mesophiles (R2 = 0.815-0.977) but not for yeasts (R2 = 0.618-0.815). The three predictive models showed that, the concentration of trans-CAH had more effect on stopping the microbial growth than the UV-C light treatment.

Biotic and Abiotic Factors to Increase Bioactive Compounds in Fruits and Vegetables

Abstract Plants, including fruits and vegetables contain a high amount of phytonutrients, biologically active compounds resulting from their secondary metabolism, which represent an important source of pharmaceuticals or nutraceutics. Historical documents indicate the use of plants to obtain medications and their use for several therapies; nowadays, approximately 25% of commercial drugs are derived from plants. These metabolites perform a significant role in plants’ adaptation and they are responsible of plant protection from different biotic or abiotic stress factors. These substances promote a defense response of plants, involving genes that encode proteins to repair and prevent cell damage, enhance the fortification of cell wall and middle lamella, produce protease inhibitors and lytic enzymes, as well as synthesize secondary metabolites with antimicrobial and antioxidant characteristics, among other responses. There are more than 200,000 known plant secondary metabolites with different functions. Therefore, the aim of this chapter is to revise, analyze, and describe the most important biotic and abiotic factors, emphasizing current investigations regarding the effect of novel methods to increase secondary metabolites in fruits and vegetables.