Optimization of Thermoultrasound Process of Soursop (Annona muricata) Nectar and Comparison of Its Physicochemical Properties and In Vitro Bioaccessibility of Antioxidants with Pasteurized Sample.

Research background: Soursop nectar contains antioxidants and is preserved by pasteurization. However, this technology impairs its physicochemical properties and bioactive compounds. An alternative is therefore thermoultrasound, which could counteract these effects. The thermosonicated nectar was compared with a pasteurized one and the in vitro bioaccessibility of antioxidants was estimated. Experimental approach: The soursop nectar (25 %) was processed and the response surface methodology was used to determine the optimal conditions for thermoultrasound treatment (TUS). The TUS (75-90 % amplitude, 3.15-15 min) was applied, and 2 % stevia and 6 % agave inulin were added as sweeteners. The microbiological, physicochemical, enzymatic and antioxidant properties were analyzed. The properties of thermosonicated nectar obtained under optimal conditions were compared with pasteurized nectar. In addition to the above determinations, microstructure, total dietary fiber (TDF) and in vitro bioaccessibility of antioxidants were determined. Results and conclusions: The response variables that fit the mathematical model were L*, b*, chroma (C*), total phenolic content (TPC) and antioxidant activity determined by ABTS•+, DPPH˙ and Fe(III) reducing antioxidant power (FRAP). The L* and DPPH˙ were affected by quadratic time and TPC by time (p<0.0001). The optimum TUS condition was 82 % amplitude for 9.15 min and the responses variables were L*, b* and C* (45.48, 3.55 and 3.62, respectively), TPC expressed as gallic acid equivalents (38.40 mg/100 mL), ABTS•+ expressed as Trolox equivalents (TE) (31.28 µmol/100 mL), DPPH˙ expressed as TE (124.22 µmol/100 mL) and FRAP expressed as Fe(II) (3.06 µmol/100 mL). Compared to the pasteurized sample, thermosonicated sample had high values of L* (45.56), h° (-56.49), TPC (26.63 mg/100 mL), ABTS•+ and DPPH˙ (22.03 and 129.22 µmol/100 mL, respectively), FRAP (3.10 µmol/100 mL) and low pectin methylesterase (PME) activity (0.28 U/mL). For in vitro bioaccessibility, thermosonicated nectar showed high absorption of TPC (15.26/100 mL) and high antioxidant activity determined by ABTS (34.92 µmol/100 mL) and FRAP (7.88 µmol/100 mL). Novelty and scientific contribution: The thermoultrasound improves the physicochemical properties and in vitro bioaccessibility of antioxidants in soursop nectar. On the other hand, as an alternative, this beverage offers low-calorie alternative with prebiotic properties that benefits consumer health.

Applications and Pharmacological Properties of Cactus Pear (Opuntia spp.) Peel: A Review.

Nowadays, there is a growing interest in the exploitation of by-products from fruits and vegetables, generated from industrial processing or human feeding. Residues of popularly consumed fruits such as orange, lemon, banana, pomegranate, among others, have been widely described and studied; however, cactus pear (Opuntia spp.) residues, as a locally consumed product, have been forgotten. The whole fruit can be divided into the edible portion (pulp) and the non-edible portion (seeds and peel). Several studies mainly focus on the characteristics of the edible portion or in the whole fruit, ignoring by-products such as peels, which are rich in compounds such as phenols, flavonoids and dietary fiber; they have also been proposed as an alternative source of lipids, carbohydrates and natural colorants. Some uses of the peel have been reported as a food additives, food supplements, as a source of pectins and for wastewater treatment; however, there have not been any deep investigations of the characteristics and potential uses of the cactus pear peel (CPP). The aim of the present paper is to provide an overview of the current research on CPP. CPP has many bio-active compounds that may provide health benefits and may also be useful in pharmaceutical, food and manufacturing industries; however, greater research is needed in order to gain thorough knowledge of the possibilities of this by-product.

Role of Bioactive Compounds in Obesity: Metabolic Mechanism Focused on Inflammation.

Obesity is a disease characterized by an inflammatory process in the adipose tissue due to diverse infiltrated immune cells, an increased secretion of proinflammatory molecules, and a decreased secretion of anti-inflammatory molecules. On the other hand, obesity increases the risk of several diseases, such as cardiovascular diseases, diabetes, and cancer. Their treatment is based on nutritional and pharmacological strategies. However, natural products are currently implemented as complementary and alternative medicine (CAM). Polyphenols and fiber are naturally compounds with potential action to reduce inflammation through several pathways and play an important role in the prevention and treatment of obesity, as well as in other non-communicable diseases. Hence, this review focuses on the recent evidence of the molecular mechanisms of polyphenols and dietary fiber, from Scopus, Science Direct, and PubMed, among others, by using key words and based on recent in vitro and in vivo studies.

Subproductos de interés nutricional y funcional de Agave salmiana

RESUMEN Agave salmiana es una subespecie originaria de México, ha sido participe en distintos periodos históricos, utilizado en la construcción, vestimenta, alimento y bebida. Destacando el aguamiel como subproducto, cuya particularidad es su alto contenido de azúcares (fructooligosacáridos). Algunos subproductos derivan del aguamiel, como el pulque y el jarabe de agave; el primero resultado de la fermentación y el segundo de la concentración de solutos mediante tratamientos térmicos y/o enzimáticos. Por lo anterior, el objetivo de esta revisión fue recopilar información de los últimos años sobre Agave salmiana y subproductos de interés nutricional y funcional, así como su uso en productos alimenticios, para lo cual se usaron las bases de datos: Medline/PubMed, SciELO, ELSEVIER, así como Normas Oficiales Mexicanas y páginas web privadas. La estrategia de búsqueda se realizó combinando el uso de operadores booleanos "AND" y "OR", utilizando las siguientes palabras: aguamiel and characterization, pulque and microorganisms or fermentation, agave syrup and bread. Esta revisión concluye que el consumo, de manera controlada, de los subproductos de Agave salmiana, trae consigo múltiples beneficios a la salud, principalmente al fortalecer la microbiota intestinal, por lo que pueden ser incluidos en la dieta habitual de una persona sana, además, pueden ser utilizados como parte del tratamiento nutricional, en bajas cantidades, en patologías como diabetes tipo 2 e intolerancia a la insulina, colitis ulcerosa y cáncer de colon siempre con supervisión médica. Por otra parte, aún existe la necesidad de generar más información sobre el tema a través de investigación científica.

ABSTRACT Agave salmiana is a native subspecies from Mexico, it has been part of different historical periods, used in construction, clothing, food and drink; highlighting the aguamiel as a by-product, whose particularity is its high sugar content (fructooligosaccharides). Some by-products are derived from aguamiel, such as pulque and agave syrup; the first is the result of fermentation and the second of the concentration of solutes by thermal and/or enzymatic treatments. Therefore, the objective of this review was to collect recent information about Agave salmiana and by-products of nutritional and functional interest, as well as use in food products. We used the following databases were used: Medline/PubMed, SciELO, ELSEVIER, as well as the Official Mexican Standards and private web pages. The search strategy was carried out with the boolean operators "AND" and "OR", using the following words: aguamiel and characterization, pulque and microorganisms or fermentation, agave syrup and bread. This review concludes that the consumption, in a controlled manner, of the by-products of Agave salmiana, brings with it multiple health benefits, mainly by strengthening the intestinal microbiota, so they can be included in the usual diet of a healthy person. In addition, by-products can be used as part of nutritional treatments, in low amounts, for diseases such as type 2 diabetes and insulin intolerance, ulcerative colitis and colon cancer, always with medical supervision. On the other hand, there is still a need to generate more information about the subject through scientific research.

Effect of Ultrasound on In Vitro Bioaccessibility of Phenolic Compounds and Antioxidant Capacity of Blackberry (Rubus fruticosus) Residues cv. Tupy.

Agro-industries residues of fruit are a source of antioxidant compounds with a possible health impact. The aim of this study was to evaluate the total phenolic content (TPC), total monomeric anthocyanins (TMA), individual phenolic compounds (IPC), antioxidant capacity and in vitro intestinal bioaccessibility from blackberry residues (BR), and ultrasonicated blackberry residues (US-BR). The results showed that BR had higher TPC (4,016.43 mg GAE/100 g DM), TMA (364.53 mg Cy-3-Gl/100 g) antioxidant capacity by ABTS (5,422.38 mg AAE/100 g DM) and FRAP (12511.44 µmol Fe(II)/100 g DM) than US-BR. TPC and TMA obtained by US-BR were more bioaccessible (70 and 51%, respectively) compared to BR (37 and 34%, respectively). The use of ultrasound can aid the extraction of total phenolic compounds and improve their bioaccessibility. After acid hydrolysis, a high amount of individual phenolic compounds (IPC) in US-BR (chlorogenic acid, caffeic acid, apigenin, luteolin and kaempferol) was obtained compared with BR. Before in vitro digestion, total individual compounds (TIC) content was lower in the BR (29.49 mg/100 g DM) than US-BR (92.36 mg/100 g DM) and there was 5 and < 1%, respectively. Therefore, the food industry would use residues of blackberry fruits as a source of antioxidant compounds with possible health benefits.

Enzymatic inactivation and antioxidant properties of blackberry juice after thermoultrasound: Optimization using response surface methodology.

The purpose of this research was to optimize the thermoultrasound conditions for blackberry juice using the response surface methodology and considering juice quality parameters and antioxidant capacity. With the exception of microbial growth, the response variables showed high correlation coefficients with the mathematical model (R2adj>0.91). Thermoultrasound treatment inactivated all the evaluated microorganisms, and at the optimum conditions (50±1°C at 17±1min) it increased enzyme inactivation and antioxidant activity in comparison to pasteurized juice. The results demonstrated that thermoultrasound can be an alternative to pasteurization for the production of safe and high-quality juices with the added value of higher concentration of bioactive compounds and antioxidant capacity.

Effects of ultrasound treatment in purple cactus pear (Opuntia ficus-indica) juice.

Cactus pear (Opuntia ficus-indica) fruit is a berry with a tasty pulp full of seeds that constitutes about 10-15% of the edible pulp. In Mexico, cactus pear is mainly consumed fresh, but also has the potential to be processed in other products such as juice. The objective of this study was to evaluate the effect of different ultrasound conditions at amplitude levels ranging (40% and 60% for 10, 15, 25 min; 80% for 3, 5, 8, 10, 15 and 25 min) on the characteristics of purple cactus pear juice. The evaluated parameters were related with the quality (stability, °Brix, pH), microbial growth, total phenolic compounds, ascorbic acid and antioxidant activity (ABTS, DPPH and % chelating activity) of purple cactus pear juices. The ultrasound treatment for time period of 15 and 25 min significantly reduced the microbial count in 15 and 25 min, without affecting the juice quality and its antioxidant properties. Juice treated at 80% of amplitude level showed an increased of antioxidant compounds. Our results demonstrated that sonication is a suitable technique for cactus pear processing. This technology allows the achievement of juice safety and quality standards without compromising the retention of antioxidant compounds.