Fatty Acids and Starch Identification within Minute Archaeological Fragments: Qualitative Investigation for Assessing Feasibility

Within the realm of archaeology, the analysis of biomolecules assumes significant importance in elucidating historical dietary patterns and their implications for contemporary contexts. To achieve this, knowledge and tools of both chemistry and archaeology are essential to yield objective outcomes and conduct analyses of archaeological materials for the detection of biomolecules. Usually, only minuscule remnants of ceramic fragments are retrieved from excavations, which limits the feasibility of comprehensive laboratory analysis. This study aimed to establish a protocol for analyzing fatty acids and starch from archaeological food utensils with minimal sample quantities. Various experiments were conducted to replicate preparations that might have occurred in archaeological vessels, aiming to establish the optimal protocol. The analyses were performed using clay griddles, subjecting vegetable oil to varying temperatures for fatty acid assessment. For starch analysis, a series of experiments encompassed diverse forms of potato preparations (pulp, chuño, tortilla, carbonization, and freeze-drying) and maize (flour, tortilla, and carbonization). The verification of the experiments was confirmed by conducting identical analyses, as developed in the current study, on authentic archaeological fragments. The principal outcomes of this investigation include the successful extraction of both types of biomolecules using only 0.25 g of the sample, obtained through direct scraping from the vessel. Soxhlet extraction was identified as the most efficient strategy to recover fatty acids. Additionally, a comprehensive protocol for the identification of starch extraction was developed. This study has, for the first time, elucidated two detailed methodologies for the extraction of fatty acids and starch in scenarios in which researchers can obtain limited quantities of archaeological food utensil fragments.

Electromagnetic fields effects on microbial growth in cocoa fermentation: A controlled experimental approach using established growth models

Understanding the effects of electromagnetic fields is crucial in the fermentation of cocoa beans, since through precise control of fermentation conditions the sensory and nutritional properties of cocoa beans could be improved. This study aimed to evaluate the effect of oscillating magnetic fields (OMF) on the kinetic growth of the core microbial communities of the Collections Castro Naranjal (CCN 51) cocoa bean. The data was obtained by three different models: Gompertz, Baranyi, and Logistic. The cocoa beans were subjected to different OMF strengths ranging from 0 mT to 80 mT for 1 h using the Helmholtz coil electromagnetic device. The viable microbial populations of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast (Y) were quantified using the colony-forming unit (CFU) counting method. The logistic model appropriately described the growth of LAB and Y under magnetic field exposure. Whereas the Baranyi model was suitable for describing AAB growth. The microbial populations in cocoa beans exposed to magnetic fields showed lower (maximum specific growth rate (μmax), values than untreated controls, with AAB exhibiting the highest average growth rate value at 5 mT and Y having the lowest average maximum growth rate value at 80 mT. The lower maximum specific growth rates and longer lag phases when exposed to magnetic fields compared to controls demonstrate the influence of magnetic fields on microbial growth kinetics.

Raman Spectroscopic and Sensory Evaluation of Cocoa Liquor Prepared with Ecuadorian Cocoa Beans Treated with Gamma Irradiation or Induced Electromagnetic Field Fermentation

Cocoa liquor is the primary precursor of the worldwide highly appreciated commodity chocolate. Its quality depends on several factors, such as the type of cocoa, the fermentation process, and the control of the contaminants in the fermented beans. This study aims to evaluate whether the induced magnetic field treatment during the fermentation process or the pathogen reduction with gamma irradiation after the fermentation affect the characteristics of the cocoa liquor obtained from Ecuadorian cocoa beans. For this purpose, liquor samples from controls (standard process), from beans treated with an induced magnetic field up to 80 mT, and from beans irradiated with nominal doses up to 3 kGy were characterized through Raman spectroscopic analysis and sensorial evaluation. The most relevant bands of the cocoa liquor were assigned according to reports from the literature, spectroscopic data, and chemometrics. The spectra corresponding to different treatments and doses were visually very similar, but they could be discriminated using OPLS-DA models, where the most intense Raman signals were attributed to the lipid components. The sensorial evaluation rated the presence of floral, fruity, almondy, acid, and bitter flavors, along with astringency and intense aroma, and these attributes exhibited variable behavior depending on the dose of the irradiation or magnetic treatment. Therefore, both treatments may exert an influence on cocoa beans and, therefore, on the cocoa liquor quality.

Corrigendum to "Optimization of cacao beans fermentation by native species and electromagnetic fields" [Heliyon 9(4) April 2023 e15065]

[This corrects the article DOI: 10.1016/j.heliyon.2023.e15065.].

Experimental Prototype of Electromagnetic Emissions for Biotechnological Research: Monitoring Cocoa Bean Fermentation Parameters

A Helmholtz-type electromagnetic emission device, which uses an oscillating magnetic field (OMF), with potential applications in biotechnological research, was built and validated. The coils were connected to an alternating current (AC) generator to generate a 0.5 to 110 mT field at their center. OMF measurements were performed with a Hall effect sensor with a digital signal connection (Arduino nano) and data output to a PC using LabVIEW v2017SP1 software. The fermentation process of the cocoa bean variety CCN 51, exposed to four levels of OMF density for 60 min (0, 5, 40, and 80 mT/60 min), was analyzed. Different variables of the grain fermentation process were evaluated over six days. The ANOVA test probed the device's linearity, accuracy, precision, repeatability, reliability, and robustness. Moreover, CCN 51 cocoa beans' EMF-exposure effect was evaluated under different OMF densities for 60 min. The results show the validity of the equipment under working conditions and the impact of EMF (electromagnetic fields) on the yield, deformation, and pH of cocoa beans. Thus, we concluded that the operation of the prototype is valid for use in biotechnological studies.

Optimization of cacao beans fermentation by native species and electromagnetic fields

Acid and bitter notes of the cocoa clone Cacao Castro Naranjal 51 (CCN 51) negatively affect the final quality of the chocolate. Thence, the fermentative process of cocoa beans using native species and electromagnetic fields (EMF) was carried out to evaluate the effect on the yield and quality of CCN 51 cocoa beans. The variables magnetic field density (D), exposure time (T), and inoculum concentration (IC) were optimized through response surface methodology to obtain two statistically validated second-order models, explaining 88.39% and 92.51% of the variability in the yield and quality of the beans, respectively. In the coordinate: 5 mT(D), 22.5 min (T), and 1.6% (CI), yield and bean quality improved to 110% and 120% above the control (without magnetic field). The metagenomic analysis showed that the changes in the microbial communities favored the aroma profile at low and intermediate field densities (5-42 mT) with high yields and floral, fruity, and nutty notes. Conversely, field densities (80 mT) were evaluated with low yields and undesirable notes of acidity and bitterness. The findings revealed that EMF effectively improves the yield and quality of CCN 51 cocoa beans with future applications in the development and quality of chocolate products.

Comparative assessment of physicochemical, structural and functional properties of dietary fiber extracted from mango (Mangifera indica L.) and soursop (Annona muricata) peels

The potential of soursop, a less well-known tropical fruit, was assessed as a source of dietary fiber (DF) and compared to mango. After optimizing the conditions to maximize the extraction yield of soluble and insoluble DF, their structural, physicochemical, and functional properties were evaluated. The results showed that soursop excelled in total and insoluble DF content (50 % higher than mango). The antioxidant response and reducing sugar content obtained for soursop were significantly higher than in mango. Yet, the insoluble fraction in both fruits was characterized by higher antioxidant activity and phenolic content. The chemical composition of both fruits revealed that glucose and potassium were the main sugar and mineral, respectively. Lactic, formic, and acetic acids were the main short-chain fatty acids produced after in vitro colonic fermentation with Lacticaseibacillus casei and Lacticaseibacillus rhamnosus, and negligible amounts of butyric, propionic, and valeric acids were detected after 48-h-fermentation, independent of the fruit. Soursop is a promising rich source of DF that can be used together with mango to develop and enhance foods' textural and nutritional characteristics.

Health risk-benefit assessment of the commercial red mangrove crab: Implications for a cultural delicacy

Mangrove forests, provide vital food resources and are an endangered ecosystem worldwide due to pollution and habitat destruction. A risk-benefit assessment (RBA) was performed on the red mangrove crab (Ucides occidentalis) from the threatened Guayas mangroves in Ecuador. It was aimed to assess the combined potential adverse and beneficial health impact associated with crab consumption and define a recommended safe intake (SI) to improve the diet of the Ecuadoran population while ensuring safe food intake. Target hazard quotients (THQs), benefit quotients (Qs), and benefit-risk quotients (BRQs) were calculated based on the concentrations of the analyzed contaminants (121 pesticide residues, 11 metal(loid)s, antimicrobial drugs from 3 classes) and nutrients (fatty acids, amino acids, and essential nutrients). Except for inorganic arsenic (iAs), the THQ was below 100 for all investigated contaminants, suggesting that the average crab consumer is exposed to levels that do not impose negative non-carcinogenic or carcinogenic health effects in the long and/or short term. Concentrations of iAs (average AsIII: 25.64 and AsV: 6.28 μg/kg fw) were of the highest concern because of the potential to cause negative health effects on long-term consumption. Despite the thriving aquaculture in the Guayas estuary, concentrations of residues of the antimicrobial drugs oxytetracycline (OTC), florfenicol, and nitrofurans still were low. Based on the fact that different risk reference values exist, related to different safety levels, four SI values (0.002, 0.04, 4, and 18 crabs/day) were obtained. The strictest intake values indicate a concern for current consumption habits. In conclusion, the red mangrove crab contains various important nutrients and can be part of a balanced diet for the Ecuadorian population when consumed in limited portions. The present study emphasizes the importance of safeguarding the quality of the environment as a prerequisite for procuring nutritious and safe food.

Variables related to microwave heating-toasting time and water migration assessment with kernel size approaches of specialty maize types

BACKGROUND

Three main maize types with specialty kernels are used to make ready-to-eat maize by traditional toasting, and microwave toasting may be an innovative application. However, little is known of the toasting process of these Andean maize types. Therefore, the present study aimed to explore the behavior of a broad scope of variables in these maize types. The kernels were packed in sealed paper envelopes and subjected to six microwave heating-toasting times from 0 to 390 s. Subsequently, with actual kernel size approaches, water content (WC), water ratio (WR), and water loss (WL) were analyzed.

RESULTS

In addition to WC, WR, and WL, the surface area (S), volume (V), and geometric mean diameter (GMD) behaved like time-related variables with a high correlation depending on the maize types and kernel dimensions. Thus, the WC, WR, and WL third-order polynomial regression curves computed with the spatial (S/V)² and distance (GMD/2)² approaches indicated the water variation at each microwave heating-toasting time with a clear difference among maize types a0, a1, and a2. Regarding their exchange profiles without and with the spatial (S/V)² approach, the maximum rates showed significant differences between maize types and WC and WL. Likewise, the maximum rates displayed significant differences between the spatial (S/V)² and distance (GMD/2)² approaches, revealing a notable lack of consistency with the distance (GMD/2)² approach.

CONCLUSION

The kernel size approaches revealed that water migration rates depended on differences in maize types. Such basic information represents the first insight into more physical-based models of water diffusion during raw microwave maize heating-toasting. © 2022 Society of Chemical Industry.

Traditional Fermented Foods from Ecuador: A Review with a Focus on Microbial Diversity

The development of early civilizations was greatly associated with populations’ ability to exploit natural resources. The development of methods for food preservation was one of the pillars for the economy of early societies. In Ecuador, food fermentation significantly contributed to social advances and fermented foods were considered exclusive to the elite or for religious ceremonies. With the advancement of the scientific research on bioprocesses, together with the implementation of novel sequencing tools for the accurate identification of microorganisms, potential health benefits and the formation of flavor and aroma compounds in fermented foods are progressively being described. This review focuses on describing traditional fermented foods from Ecuador, including cacao and coffee as well as less popular fermented foods. It is important to provide new knowledge associated with nutritional and health benefits of the traditional fermented foods.

Valorization of byproducts from tropical fruits: A review, Part 2: Applications, economic, and environmental aspects of biorefinery via supercritical fluid extraction

The global trade of tropical fruits is expected to increase significantly in the coming years. In 2018, the production was approximately 100 million tones, an increase of 3.3% compared to the previous year. Nevertheless, according to the Food and Agricultural Organization, every year one-third of the food produced in the world for human consumption is lost or wasted. More specifically, around 45% of the fruits, constituted mainly by peels, seeds, and pulps after juice extraction, are discarded mainly in the agricultural and processing steps. Therefore, decreasing and/or using these byproducts, which are often rich in bioactive components, have become an important focus for both the scientific community and the fruit processing industry. In this line, supercritical fluid extraction (SFE) technology is expected to play a significant role in the valorization of these byproducts. This review presents the concepts of a tropical fruit biorefinery using supercritical CO₂ extraction and the potential applications of the isolated fractions. There is a specific focus on the extraction of bioactive compounds, that is, carotenoids and phenolics, but also oils and other valuable molecules. Moreover, the techno-economic and environmental performance is assessed. Overall, the biorefinery of tropical fruits via SFE provides new opportunities for development of food and pharmaceutical products with improved economic and environmental performance.

Geographical variations in arsenic contents in rice plants from Latin America and the Iberian Peninsula in relation to soil conditions

Arsenic is a ubiquitous, toxic element that is efficiently accumulated by rice plants. This study assessed the spatial variability in the total As (tAs) contents and organic and inorganic forms in different types of rice, plant parts (husk, stem, leaves and phytoliths) and residues. Samples were collected in different countries in Latin America (Ecuador, Brazil and Peru) and the Iberian Peninsula (Spain and Portugal). The tAs content in commercial polished rice from the Latin American countries was similar (0.130-0.166 mg kg^-1) and significantly lower than in the rice from the Iberian countries (0.191 ± 0.066 mg kg^-1), and together, the tAs concentration in brown rice (236 ± 0.093 mg kg^-1) was significantly higher than in polished and parboiled rice. The inorganic As (iAs) content in rice was similar in both geographical regions, and the aforementioned difference was attributed to dimethylarsinic acid (DMA). The relative abundance of organic species increased as the tAs content in rice grain increased. A meta-analysis of our and previously reported data confirmed the negative correlation between iAs/tAs and tAs. At low tAs concentrations, inorganic forms are dominant, while at higher values (tAs > 0.300 mg kg^-1) the concentration of organic As increases substantially and DMA becomes the dominant form in rice grain. On the contrary, inorganic arsenic was always the dominant form, mainly as arsenate [As(V)], in leaves and stems. The presence in soils of high concentrations of amorphous Fe and Al oxides and hydroxides, which are capable of strongly adsorbing oxyanions (i.e. arsenate), was associated with low concentrations of As in rice plants. In addition, the presence of high concentrations of As(V) in stems and leaves, low concentration of As in phytoliths, and the As associated with organic matter in stems and husk, together suggest that rice plants take up more As(V) than As(III).

Assessment of cadmium and lead contamination in rice farming soils and rice (Oryza sativa L.) from Guayas province in Ecuador

Rice is the world's most consumed and in-demand grain. Ecuador is one of the main rice-consuming countries in Latin America, with an average per capita consumption of 53.2 kg per year. Rice cultivation takes place under flooding conditions, which favors the mobilization and subsequent accumulation of heavy metals in the plant. This study's principal objective was to evaluate the contamination of cadmium (Cd) and lead (Pb) in the rice cultivation system in the province of Guayas. To this end, extensive sampling of water, soil and rice grains was carried. Water samples were analyzed to determine physicochemical properties and concentrations of dissolved Cd and Pb. Physicochemical properties, total organic carbon (TOC), total content of nitrogen (N), iron (Fe), manganese (Mn), phosphorus (P), bioavailable phosphorus (P mehlich), Cd and Pb were determined in soil samples. In addition, to understand the dynamics of Cd and Pb mobility and bioavailability, an extraction of six randomly selected soil samples was carried out. The concentration values of the total Cd and Pb content in the rice cultivation system did not exceed the maximum recommended limit for soil, water and rice grains. However, 85% of the total Cd was in the soluble or exchangeable fraction of the soil, while the Pb was strongly bound to crystalline iron oxyhydroxides. It was established that the TOC, N, Fe, and P mehlich have a significant correlation (p < 0.05) with the overall concentration of Cd and Pb in the rice farming soil. The Cd and Pb present in rice do not represent a dietary health risk to the population of Ecuador.

Valorization of byproducts from tropical fruits: Extraction methodologies, applications, environmental, and economic assessment: A review (Part 1: General overview of the byproducts, traditional biorefinery practices, and possible applications)

Tropical fruits represent one of the most important crops in the world. The continuously growing global market for the main tropical fruits is currently estimated at 84 million tons, of which approximately half is lost or wasted throughout the whole processing chain. Developing novel processes for the conversion of these byproducts into value-added products could provide a viable way to manage this waste problem, aiming at the same time to create a sustainable economic growth within a bio-economy perspective. Given the ever-increasing concern about sustainability, complete valorization through a bio-refinery approach, that is, zero waste concept, as well as the use of green techniques is therefore of utmost importance. This paper aims to report the status on the valorization of tropical fruit byproducts within a bio-refinery frame, via the application of traditional methodologies, and with specific attention to the extraction of phenolics and carotenoids as bioactive compounds. The different types of byproducts, and their content of bioactives is reviewed, with a special emphasis on the lesser-known tropical fruits. Moreover, the bioactivity of the different types of extracts and their possible application as a resource for different sectors (food, pharmaceutical, and environmental sciences) is discussed. Consequently, this review presents the concepts of tropical fruit biorefineries, and the potential applications of the isolated fractions.

Influence of earthworm bioturbation on metals phytoavailability and human gastric bioaccessibility

At the global scale, urban agriculture is increasingly developing in cities due to demographic growth and sustainable food concerns. But, urban soils are frequently polluted with metals. In urban gardens, organic matter is also commonly added both to valorize organic household waste and to promote biophysicochemical fertility. As earthworms promote the decomposition and the recycling of soil organic matter, they can also influence the biogeochemical cycle of metals in urban polluted soils. In order to produce safe vegetables in urban areas, it is crucial to highlight the mechanisms involved in complex soil-earthworm-plant ecosystems. An experiment was set up to examine these relationships using lettuce cultivated in controlled conditions with RHIZOtest® devices. Thanks to the RHIZOtest® devices, metal transfer and bioaccessibility were for the first time compared for urban polluted soil without (1-urban soil polluted with Pb, Cd, Cu, and Zn: essential or toxic metals currently found in environment, SNB) and with bioturbation (2-this metal-polluted soil subjected to earthworm bioturbation, SB) and earthworm casts (3-earthworm casts produced in this polluted soil and naturally enriched in organic matter and microorganisms, T). Metal concentration, phytoavailability, and human gastric bioaccessibility were determined in the different samples. Results showed that earthworm bioturbation increased the phytoavailability of all the metals. For the experimental condition SB, the phytoavailability of metals was increased up to 75% compared to SNB. In addition, surprisingly, metal phytoavailability was always superior in SB compared to earthworm casts (T). Moreover, earthworms led to an increase in Zn gastric bioaccessibility up to 10% in the soils in the same way as for phytoavailability, meaning Zn bioaccessibility in SB > T > SNB, whereas it remained unchanged in the lettuces. These data are important to promote sustainable agriculture activities in urban areas; actually, databases concerning different experimental conditions are needed to develop decision support tools.

Cadmio y arsénico en chocolate y arroz de Quito, Guayaquil y Cuenca – Ecuador

El cadmio (Cd) y arsénico (As) son elementos presentes a lo largo de la cordillera de los Andes. Estos elementos representan un riesgo para la salud humana debido a las afectaciones para la salud que puede ocasionar la permanente exposición a estos elementos, los cuales pueden estar presentes alimentos como el chocolate y el arroz. El presente estudio tuvo como objetivo la evaluación de las concentraciones totales de arsénico y Cden chocolates, arroz, suelos y granos de cacao con el fin de identificar el grado de contaminación presente en estos alimentos. Las muestras de chocolate fueron recolectadas en Ecuador, en las provincias de Quito, Guayaquil y Cuenca, mientras que el arroz fue recolectado en la provincia del Guayaquil. Las muestras fueron procesadas y analizadas mediante la técnica de Espectroscopia de Absorción Atómica por Horno de Grafito (GFAAS). Las muestras de chocolate, únicamente una sobrepasó el límite máximo de 0,8 mg/kg para el Cd para consumo humano, mientras que las muestras de arroz no sobrepasaron el límite de máximo de 0,4 mg/kg. El arsénico en las muestras de chocolate presentó concentraciones inferiores al límite de detección, mientras que las muestras de arroz no sobrepasaron el límite de 0,2 mg/kg para consumo humano. En los suelos de cacao, unas de veinte muestras de Guayaquil sobrepasaron el límite de 0,50 mg/kg, mientras que, de las muestras, en particular de una hacienda aledaña a la ciudad de Quito, cinco de doce muestras sobrepasan el límite de Cd, pero las muestras de cacao allí encontradas no sobrepasaron el límite de 0,8 mg/kg. A partir de los resultados se concluye que no existe riesgo en las muestras de chocolate y arroz para la salud humana.

Biological Active Ecuadorian Mango 'Tommy Atkins' Ingredients-An Opportunity to Reduce Agrowaste

Mango is a commercially important tropical fruit. During its processing, peel and seed kernel are discarded as waste but they could be recovered as an excellent and cost-effective source of health-promoting ingredients. This study aimed to characterize some of them, including carotenoids like the provitamin A β-carotene and lutein, with an interest beyond its role in eye health. Other health-promoting compounds like tocopherols and polyphenols were also evaluated, as well as the in vitro antioxidant capacity of mango by-products. Regarding isoprenoids, α-tocopherol was mainly found in the peels and carotenoids concentration was higher in the pulps. β-carotene was the most abundant carotene in pulp and seed kernel, whereas peel was the only source of lutein, with violaxanthin the most abundant xanthophyll in the different mango organs tested. With regard to polyphenols, peels exhibited greater variability in its phenolic composition, being the total content up to 85 and 10 times higher than the pulp and seed kernels, respectively. On the other hand, peels also stood out for being a very rich source of mangiferin. Seed kernels and peels showed higher antioxidant capacity values than the pulps. These results contribute to the valorization of mango by-products as new natural ingredients for the pharma and food industries.

Chemical, antimicrobial, and molecular characterization of mortiño (Vaccinium floribundum Kunth) fruits and leaves

Fruits and leaves of Vaccinium spp. are known for their high content of bioactive compounds, but the chemical and biological characteristics of mortiño (Vaccinium floribundum Kunth) have not been fully described. In this study, the levels of polyphenols, antioxidant capacity, anthocyanins, antimicrobial activity, and genetic variability were determined in mortiño plants. The Folin-Ciocalteu's, ABTS scavenging, pH differential, and well diffusion methods were used to evaluate the levels of polyphenols, antioxidant capacity, anthocyanins, and antimicrobial activity, respectively. The genetic variability was evaluated by sequencing of the matK and rbcl DNA regions. Polyphenol content was up to 229.81 mg gallic acid equivalents/100 g, the average antioxidant capacity was 11.01 mmol Trolox equivalents/100 g, and anthocyanin content was up to 1,095.39 mg/100 g. Mortiño extracts significantly inhibited the growth of Gram-negative bacteria including Burkholderia gladioli, Burkholderia cepacia, Salmonella Typhimurium, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio vulnificus, Escherichia coli, and Pseudomona aeruginosa, as well as Gram-positive bacteria such as Probionibacterium propionicum, Staphylococcus aureus, and Enterococcus faecalis showing greater inhibition halos than those produced by the antibiotic ampicillin. A polymorphic nucleotide was found in position 739 of the matK region. This study shows the potential of mortiño for the food and pharmaceutical industries.

Changes in phytochemical composition, bioactivity and in vitro digestibility of guayusa leaves (Ilex guayusa Loes.) in different ripening stages

BACKGROUND

Guayusa (Ilex guayusa Loes.) leaves, native of the Ecuadorian Amazon, are popularly used for preparing teas. This study aimed to assess the influence of leaf age on the phenolic compounds and carotenoids and the bioactivity and digestibility (in vitro) of aqueous and hydroalcoholic leaf extracts.

RESULTS

In total, 14 phenolic compounds were identified and quantified. Chlorogenic acid and quercetin-3-O-hexose were the main representatives of the hydroxycinnamic acids and flavonols respectively. Seven carotenoids were quantified, lutein being the main compound. Ripening affected phenolic content significantly, but there was no significant difference in carotenoid content. Antioxidant capacity, measured by the DPPH^• method, was also significantly affected by leaf age. The measurement of in vitro digestibility showed a decrease in phenolic content (59%) as well as antioxidant capacity, measured by the ABTS^•+ method, in comparison with initial conditions of the guayusa infusion. Antibacterial and anti-inflammatory activities were assayed with young leaves owing to their higher phenolic contents. Guayusa did not show any antibacterial activity against Escherichia coli ATCC 25922 or Staphylococcus aureus ATCC 25923. Finally, the hydroalcoholic and aqueous extracts exhibited high in vitro anti-inflammatory activity (>65%).

CONCLUSION

Young guayusa leaves have potential applications as a functional ingredient in food and pharmaceutical industries. © 2017 Society of Chemical Industry.

Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador

Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg^-1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0-20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg^-1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.

Guayusa (Ilex guayusa L.) new tea: phenolic and carotenoid composition and antioxidant capacity

BACKGROUND

Guayusa (Ilex guayusa Loes) is an evergreen tree native of South America that grows particularly in the upper Amazon region of Ecuador. For its health benefits, it has been cultivated and consumed since ancient times by Amazon indigenous tribes.

RESULTS

A total of 14 phenolic compounds were identified and quantified. Chlorogenic acid and quercetin-3-O-hexose were the main representatives of the hydroxycinnamic acids and flavonols, respectively. Five carotenoids were identified, showing lutein the highest concentration. Guayusa leaves revealed high antioxidant capacity determined by two analytical methods, DPPH and ORAC. The industrial processing applied to the leaves modified the composition of bioactive compounds and antioxidant capacity of guayusa. In general, blanched guayusa retained the concentration of phenolic compounds and some carotenoids and similar antioxidant capacity as untreated green leaves. In contrast, fermentation reduced the content of bioactive compounds and showed the lowest antioxidant capacity.

CONCLUSION

Therefore, blanched guayusa has potential for product development as a functional ingredient in the food industry. © 2017 Society of Chemical Industry.

Banana Passion Fruit (Passiflora mollissima (Kunth) L.H. Bailey): Microencapsulation, Phytochemical Composition and Antioxidant Capacity

Passiflora mollissima (Kunth) L.H. Bailey is an exotic fruit native to South America, known as taxo in Ecuador. This paper characterizes its flavonoid and carotenoid composition and antioxidant capacity and evaluates the effect of the spray-drying process on its phytochemical composition and antioxidant capacity. A total of 18 flavonoid compounds, nine proanthocyanidins and nine flavan-3-ol monomers, were identified and quantified. Glycosides of (epi)-afzelechin stood out as the most abundant flavonoid. Three carotenoids were identified, with β-carotene having the highest concentration. The DPPH^· and ORAC assay methods indicated a high antioxidant capacity. Furthermore, the bioactive content showed a positive and direct correlation with antioxidant capacity. On the other hand, the spray-drying process produced a stable phytochemical composition and antioxidant activity of taxo. These results demonstrate the potential applicability of microencapsulated taxo as a functional ingredient in the food industry.

Arsenic in rice agrosystems (water, soil and rice plants) in Guayas and Los Ríos provinces, Ecuador

Geogenic arsenic (As) can accumulate and reach high concentrations in rice grains, thus representing a potential threat to human health. Ecuador is one of the main consumers of rice in South America. However, there is no information available about the concentrations of As in rice agrosystems, although some water bodies are known to contain high levels of the element. We carried out extensive sampling of water, soil, rice plants and commercial rice (obtained from local markets). Water samples were analysed to determine physico-chemical properties and concentrations of dissolved arsenic. Soil samples were analysed to determine total organic C, texture, total Fe and amorphous Fe oxyhydroxides (Fe_Ox), total arsenic (tAs) and the bioavailable fraction (As_Me). The different plant parts were analysed separately to determine total (tAs), inorganic (iAs) and organic arsenic (oAs). Low concentrations of arsenic were found in samples of water (generally <10μgl^-1) and soil (4.48±3mgkg^-1). The tAs in the rice grains was within the usual range (0.042-0.125mgkg^-1 dry weight, d.w.) and was significantly lower than in leaves (0.123-0.286mgkg^-1 d.w.) and stems (0.091-0.201mgkg^-1 d.w.). The Fe_Ox and tAs and also As_Me in flood water were negatively correlated with tAs in the plants. However, the concentrations of As in stems and leaves were linearly correlated with tAs in the soil and flood water. The relationship between tAs and arsenic in the grain fitted a logarithmic function, as did that between tAs in the grain and the stem. The findings seem to indicate that high concentrations of arsenic in the environment (soil or water) or in the rice stem do not necessarily imply accumulation of the element in the grain. The iAs form was dominant (>80%) in all parts of the rice plants.

Chemical composition and phenolic compound profile of mortiño (Vaccinium floribundum Kunth)

The phenolic compounds in mortiño (Vaccinium floribundum Kunth, family Ericaceae) from the páramos of Ecuador were studied by LC-DAD-MS/MS for the first time. (-)-Epicatechin, one dimer A and one trimer A were found at a total concentration of 18 mg/100 g FW. Of the flavonol glycosides (38 mg/100 g FW), quercetin and myricetin were found as -3-O-hexosides, -3-O-pentosides and -3-O-deoxyhexosides. Chlorogenic and neochlorogenic acids together with caffeic/ferulic acid derivatives were found as predominant components among the hydroxycinnamic acids in the berry. Anthocyanins, including cyanidin and delphinidin derivatives, were the major phenolic compound class quantified (345 mg cyanidin-3-O-glucoside/100 g FW).

Physical and chemical characteristics of golden-yellow and purple-red varieties of tamarillo fruit (Solanum betaceum Cav.)

Golden-yellow and purple-red tamarillos (Solanum betaceum Cav.) cultivated in Ecuador were studied for their physical properties, proximate composition, pH, degrees Brix, acidity, sugars, organic acids, minerals, vitamin C and beta-carotene content in the edible part. Results were compared with those for Spanish fruits. The golden-yellow and purple-red Ecuadorian fruits were larger (107 and 188 g) than the respective Spanish fruits (43 and 63 g), softer but generally similar in chemical composition except for fat (0.72 and 0.6%) and malic acid (0.32 and 0.53%) contents in the golden-yellow and purple-red Ecuadorian fruits. Tamarillo fruits are a good source of potassium (approximately 400 mg/100 g fresh weight). Total phenolics in the golden-yellow and purple-red varieties were 125 and 187 mg gallic acid equivalents/100 g fresh weight, respectively. The golden-yellow variety had weaker anti-DPPH radical activity than the purple-red variety. Flavonols were only found in the peel of both varieties, while hydroxycinnamic acid derivatives were found in peel and pulp.

Phenolic compounds in Rosaceae fruits from Ecuador

RP-HPLC-DAD was used to study the content of phenolic compounds in four Ecuadorian fruits (strawberry, Andean blackberry, plum, and capuli cherry). Compounds were identified using spectral characteristics of representative standards and reference samples. Further, LC-MS with MS/MS was used to confirm molecular assignments in previously unstudied capuli cherry. Gallic acid was detected in Andean blackberry, and galloyl esters were detected in strawberries. Both these berries contained ellagic acid derivatives as major compounds, followed by anthocyanins, cyanidin, and pelargonidin glycosides. Plums and capuli cherry showed similar profiles of phenolic compounds, with chlorogenic and neochlorogenic acids being the most important hydroxycinnamates. (-)-Epicatechin was found in high amounts in Andean blackberry, plums, and capuli cherry, while (+)-catechin was only found in capuli cherry. Proanthocyanidins were major compounds in all fruits, and all contained considerable amounts of quercetin derivatives and smaller amounts of kaempferol derivatives. LC-MS analysis of capuli cherry revealed dimeric and trimeric procyanidins, quercetin and kaempferol hexosides and pentosides, and a kaempferol-O,C-dipentoside.

Identifying carotenoids and phenolic compounds in naranjilla (Solanum quitoense Lam. var. Puyo hybrid), an Andean fruit

The naranjilla or lulo (Solanum quitoense Lam.) is a little known fruit that originated in the Andes. Commonly consumed as a fresh drink, it is particularly appreciated for its aroma. Besides its organoleptic qualities, the naranjilla also seems to have good antioxidant properties. We therefore studied the physicochemical characteristics of variety "Puyo hybrid"; determined its juice composition; identified its carotenoids and phenolic compounds, using HPLC-DAD and HPLC/ESI-MS, respectively, in each fruit part; and measured the antioxidant capacities of each part, using the ORAC and DPPH methods. We found the following bioactive compounds: all-trans-beta-carotene, 13-cis-beta-carotene, and 9-cis-beta-carotene and the lutein (carotenoids); chlorogenic acids and their hexosides in the flesh and placental tissues, and flavonol glycosides in the skin (phenolic compounds); and many dihydrocaffeoyl spermidines in all three parts of the fruit. The naranjilla appeared to be a fruit with good nutritional potential that can provide the basis for a new fruit-drink flavor or other fruit derived-products.

Characterization of typo-, regio-, and stereo-selectivities of babaco latex lipase in aqueous and organic media

The unripe fruit of babaco (Vasconcellea x heilbornii; syn. Carica pentagona) contains a latex, similar to that in Carica papaya, which exhibits lipolytic activity. Herein, the regioselectivity, stereoselectivity and typoselectivity in both hydrolysis and acyltransfer reactions of babaco latex lipases were studied and compared to those of Carica papaya latex. In hydrolysis, both biocatalysts are 1,3-regioselective with ratios for 1,2-2,3-diacylglycerols/1,3-diacylglycerol of 6.5 and 21 for babaco and papaya, respectively. In contrast, papaya latex had a slight sn-3 stereopreference. Babaco latex displayed a higher activity on triacylglycerols with short chain and unsaturated fatty acids.

Comparison of the lipase activity in hydrolysis and acyl transfer reactions of two latex plant extracts from babaco (Vasconcellea x Heilbornii Cv.) and Plumeria rubra: Effect of the Aqueous microenvironment

The enzymatic properties of Plumeria rubra latex have been evaluated for the first time, showing a high activity in both hydrolysis and synthesis reactions, and compared to the biocatalytic behavior of babaco (Vasconcellea x Heilbornii cv.) latex. Both biocatalysts have been optimized by studying the various parameters that influence reaction kinetics. The optimum temperatures for hydrolysis reactions were 50 and 55 degrees C for babaco and Plumeria, respectively. The optimum pH for babaco latex was 7, whereas for Plumeria latex, two optimal pH values (4 and 7) were observed. With regard to esterification and acyl transfer reactions such as alcoholysis and interesterification, the influence of thermodynamic water activity on reaction yields was determined and correlated with water sorption and desorption isotherms. When babaco latex is used as a biocatalyst, optimal synthesis reaction yields are obtained when the enzymatic extract is stabilized at a water activity value of 0.38, which corresponds to a water content of 5.7%. This optimal level of hydration is located on the linear portion of the biocatalyst's sorption isotherm, where the water molecules exhibit high-energy interactions with the protein network. In synthesis reactions (esterification, alcoholysis, and interesterification) biocatalyzed by Plumeria latex, correlation between best reaction yields and water activity cannot be done. Indeed, the sorption isotherm plot has an atypical shape, indicating that water might be trapped in the latex matrix and, consequently, that the water content of the biocatalyst is highly dependent on the hydration history of the latex.

Preparation of indigestible pyrodextrins from different starch sources

Starch-modifying processes, such as pyrodextrinization, are potential ways to alter the nutritional features of this polysaccharide. A widely used method for pyrodextrinizing maize starch was also applied to lentil, sorghum, cocoyam, sagu, and cassava starches, and the in vitro digestibility of the products was evaluated. Pyrodextrins were produced by heating starch at 140 degrees C for 3 h, with catalytic amounts of HCl. The enzymatically available starch content of all preparations decreased by 55-65% after modification. Thus, pyrodextrinization seems to be an effective way to produce indigestible glucans from different starches. Pyrodextrins obtained were complex mixtures of starch derivatives with a wide range of molecular weight as estimated by gel filtration chromatography. Both their molecular weight profiles and contents of indigestible fractions varied with starch source. Experiments with lentil and cassava starches showed that changing dextrinization conditions also affects the susceptibility to enzymatic hydrolysis of the product.

[Optimization of a spaghetti formula enriched with dietary fiber and micronutrients for elderly people]

Several studies have demonstrated low dietary fiber intake in elderly people, which increases the risk of diseases such as constipation, colon cancer and diverticulosis. A spaghetti formula enriched with lupin fibre was developed to increase the dietary fibre intake in elderly people, as spaghetti are frequently consumed in this age group. Sweet lupin bran (Vitafiber) was used as fibre source and gluten was used as improving additive. Response surface methodology with a two variable composite rotatable design was applied to optimize the formulations. The independent variables were lupin bran (7.14-14.29%) and gluten Vital (0.1-2.0%). The dependent variables were the responses of a trained 10-member sensory panel who evaluated the sensory quality parameters color, shape, aroma, flavor and texture by the Karlsruhe 9-point test. The optimized formula was prepared with 66.7% semoline, 7.14% lupin bran, 1.05% gluten and 24.7% water, enriched with 0.019% of a vitamin premix (A. E, D, B2, B12 and folic acid) and with 0.41% of a mineral premix (Ca, Fe, Zn), in order to meet 30% of the RDA for the elderly per 100 g dry spaghetti. The dietary fibre content of the optimized product was 11.05 g/100 g. The study showed that fibre-enriched spaghetti formula is a good way to increase dietary fibre intake in elderly people, as it is a common food, simple to prepare and easy to eat.

The nutritional quality of an infant food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in undernourished children

An infant food product was manufactured by drum drying a pre-cooked slurry of quinoa (Chenopodium quinoa, Willd) flour. The chemical composition shows that the product is a potential source of valuable nutrients, like protein (16%), vitamin E (19 mg/kg), thiamine (0.7 mg/100 g), iron (70 mg/kg), zinc (48 mg/kg) and magnesium (1.8 g/kg), all the values expressed on dry basis, to pre-school children (of 5 years of age). The animal feeding experiments with rats showed a net protein utilisation (NPU) of 68, digestibility (TD) 95 and biological value (BV) 71. The level of insulin-like growth factor-1 (IGF-1) in the plasma of the children who consumed a supplementary portion of 2 x 100 g of the above infant food product showed an increase after a period of 15 days, while the plasma level of IGF-1 in the children of the control group as well as the reference group did not show any significant increase.