Loreto A. Muñoz

Chia Seed (Salvia hispanica): An Ancient Grain and a New Functional Food

Chia seed (Salvia hispanica) is an ancient oilseed used by Mayas and Aztecs as foodstuff. This seed is a natural source of omega-3 fatty acids (α-linolenic acid), soluble and insoluble fibers, and proteins in addition to other important nutritional components, such as vitamins, minerals, and natural antioxidants. Chia can be considered as “functional food” because apart from contributing to human nutrition, chia helps to increase satiety index, prevent cardiovascular diseases, inflammatory and nervous system disorders, and diabetes, among others. Today, chia seed offers a huge potential in the industries of health, food, animal feed, pharmaceuticals, and nutraceuticals, among others, due to its functional components.

Determination of polyphenolic profile, antioxidant activity and antibacterial properties of maqui [Aristotelia chilensis (Molina) Stuntz] a Chilean blackberry.

BACKGROUND The aim of the present study was to determine (1) the polyphenolic profile (phenolic acids, flavonoids and anthocyanins), (2) the antioxidant using four different methodologies (DPPH, ABTS, FRAP and FIC) and (3) the antibacterial properties of maqui berry [Aristotelia chilensis (Molina) Stuntz] (MB) grown in Chile. RESULTS The HPLC analysis of MB showed a total of 19 polyphenolic compounds identified as anthocyanins (eight compounds), flavonols (10 compounds) and ellagic acid. Delphinidin derivatives were the predominant anthocyanins while quercetin derivatives were the predominant flavonols. MB showed an antioxidant activity measured with DPPH, ABTS, FRAP and FIC methods of 28.18, 18.66, 25.22 g Trolox equivalent kg(-1) and 0.12 g ethylenediaminetetraacetic acid equivalent kg(-1) , respectively. With regard to the antibacterial activity, all strains tested were affected by MB. Aeromonas hydrophila and Listeria innocua showed the highest sensitivity to maqui berry extracts with MIC values of 40 and a 50 mg mL(-1) , respectively. CONCLUSIONS The results suggest that maqui berry has a great potential to be employed in the food industry as potential food ingredient to functional food development or as bio-preservative.

Comparison of vacuum and atmospheric deep-fat frying of wheat starch and gluten based snacks

Vacuum frying was compared with atmospheric frying in the development of wheat starch and gluten based snacks in terms of oil uptake, texture, expansion, and color development. The comparison was based on the concept of equivalent thermal driving force (ETDF) (i.e., keeping a constant difference between the oil temperature and boiling point of water at the working pressure). Vacuum fried snacks were observed to absorb lower oil content at all ETDFs and as low as 27% less of atmospherically fried samples and lighter in color. A very strong relationship existed between texture and oil content on one hand; and expansion and oil content on the other hand for fried matrices from both technologies. SEM was used in validating the result. Vacuum frying can be used for the development of acceptable fabricated fried snacks from wheat starch and gluten with lower oil content and acceptable textural and color properties.

Optimization of processing conditions for vacuum frying of high quality fried plantain chips using response surface methodology (RSM)

Optimization of processing conditions (temperature 122 to 136°C, vacuum pressure 9.91 to 19.91 cmHg, and frying time 3 to 9 min) during vacuum frying of plantain chips was investigated using a Box-Behnken experimental design with response surface methodology (RSM). Models for various responses were developed and optimized frying conditions using numerical solutions were established. Optimized vacuum fried samples were compared with atmospheric fried samples based on the concept of equivalent thermal driving force (ETDF). Frying parameters had significant (p<0.05) effects on the moisture content, texture, and color with a coefficient of determination (R2) for quadratic model responses varying between 0.53 and 0.99. Optimum vacuum frying conditions for plantain chips were a frying temperature of 133°C, vacuum pressure of 9.91 cmHg, and frying time of 6 min based on desirability concepts. Vacuum fried plantain chips had more acceptable sensory properties, based on ETDF values, than atmospheric fried samples.

Total liver fat quantification using three-dimensional respiratory self-navigated MRI sequence

MRI can produce quantitative liver fat fraction (FF) maps noninvasively, which can help to improve diagnoses of fatty liver diseases. However, most sequences acquire several two‐dimensional (2D) slices during one or more breath‐holds, which may be difficult for patients with limited breath‐holding capacity. A whole‐liver 3D FF map could also be obtained in a single acquisition by applying a reliable breathing‐motion correction method. Several correction techniques are available for 3D imaging, but they use external devices, interrupt acquisition, or jeopardize the spatial resolution. To overcome these issues, a proof‐of‐concept study introducing a self‐navigated 3D three‐point Dixon sequence is presented here.

Erratum to “Assessment of rheological and microstructural changes of soluble fiber from chia seeds during an in vitro micro-digestion” [LWT 95 (2018) 58–64]

Erratum to “Assessment of rheological and microstructural changes of soluble fiber from chia seeds during an in vitro micro-digestion” [LWT 95 (2018) 58–64] Henry Lazaro, Luis Puente, María C. Zúñiga, Loreto A. Muñoz Universidad de Chile, Departamento de Ciencias de los Alimentos y Tecnología Química, Santos Dumont 964, Independencia, Santiago, Chile Universidad de Chile, Facultad de Cs. Químicas y Farmacéuticas, Depto. Química Orgánica y Analítica, Santos Dumont 964, Independencia, Santiago, Chile Universidad Central de Chile, Facultad de Ingeniería, 8330601, Santiago, Chile

Experimental and Mathematical Description of Sorption Isotherms and Thermodynamic Properties of Salted and Dried African Catfish (Clarias gariepinus)

Sorption isotherms and thermodynamic properties of brine salted and dried (BSD) and dry salted and dried (DSD) African catfish in the water activity (aw) range (0.33-0.85) was determined and compared at 25, 30 and 40C using the static gravimetric method of saturated solutions. Five sorption models: GAB (Guggenheim-Anderson-de Boer), BET (Brunauer-Emmett-Teller), Kuhn, Adam and Shove and Henderson were fitted with the experimental sorption data obtained. Curves for both samples followed the type III BET classification scheme. Equilibrium moisture content (EMC) decreased with increase in temperature at low and intermediate aw (0.33-0.65) while there was an inversion of this trend at higher aw (0.75-0.85) with DSD samples having higher values at the same experimental conditions. GAB model predicted best with the monolayer values varying between 0.047 to 0.054 kg/kg db for BSD samples and 0.047 to 0.052 kg/kg db for DSD samples. Salting technique affected significantly the properties investigated