Food associated diseases pose significant public health threat in the United States. Health risks... more Food associated diseases pose significant public health threat in the United States. Health risks associated with food-borne pathogens drive the need for constant monitoring of food products. An efficient method that can diagnose food-borne pathogens rapidly will be invaluable and in high demand. In this study, we showed the feasibility of a novel rapid detection platform based on fluorescence imaging/detection that combines a user-friendly, portable loop mediated isothermal amplification (LAMP) reaction device and a smartphone-based detection system. The proposed platform was used to detect Staphylococcus aureus which is one of the most important food-borne pathogen especially dairy products. The complete protocol is quicker; the reaction is performed under isothermal conditions and completed in 1 h or less. Experimental results show that LAMP assays were tenfold more sensitive than PCR-based detection. The proposed smartphone detection system was able to detect and quantify LAMP assay samples containing three different concentrations of S. aureus from 10 9 CFU/mL down to 10 3 CFU/mL. The present proof-of-concept study demonstrated that this platform offers a portable, easy to use method for measuring target pathogens with LAMP amplification. Food-borne pathogens are defined as biological agents that cause food-borne illness; they can be either viruses, bacteria and eukaryotes like funguses, protozoa or helminths 1. Every year, the Food and Drug Administration (FDA) reports the outbreaks associated with food-borne pathogens; for instance, in 2020, it reported the contamination of Escherichia coli, Listeria monocytogenes and Cyclospora in clover sprouts, Enoki mushrooms and bagged salad, respectively (FDA 2020). Health risks associated with food-borne pathogens drive the need for constant monitoring of food products. For microbial pathogen detection, the conventional method is bacterial growth on a culture medium then on selective agar; it sometimes involves biochemical or serological testing. This process has some disadvantages because it is time consuming, laborious and detection of non-culturable pathogens is not possible 2. By following the conventional methodology, the detection of E. coli O157 takes around 3 days, Salmonella 4-6 days and Vibrio parahaemolyticus around 7 days 3. For this reason, new techniques emerged which provide faster, more reliable and sensitive results; some of the most widely used are the polymerase chain
Jujube, commonly known as the Chinese date, is a nutritious fruit with medicinal importance. Fres... more Jujube, commonly known as the Chinese date, is a nutritious fruit with medicinal importance. Fresh jujube fruits have a shelf life of about ten days in ambient conditions that can be extended by drying. However, nutrition preservation varies with the drying method and parameters selected. We studied total phenolic content (TPC), proanthocyanidins (PA), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant activities in jujube fruits dried with freeze-drying (FD), convective oven drying (OD) at 50 °C, 60 °C, and 75 °C, and sun drying (SD) with FD as a control. The cultivars used for this study were ‘Capri’ and ‘Xiang’ from Las Cruces in 2019, and ‘Sugarcane’, ‘Lang’, and ‘Sherwood’ from Las Cruces and Los Lunas, New Mexico, in 2020. Freeze-drying had the highest of all nutrient components tested, the best estimates of mature jujube fruits’ nutrient contents. Compared with FD, the majority of PA (96–99%) and vitamin C (90–93%) was lost during SD or OD processes. The retent...
Given consumer trends propelling a movement toward using plant protein in the food industry and s... more Given consumer trends propelling a movement toward using plant protein in the food industry and searching for alternative protein ingredients by the industry, this study aimed to assess the influence of factors such as protein concentration, medium pH, and the presence of a divalent ion (Ca2+) upon the rheological properties such as viscosity change and gel formation of dispersion proteins extracted from quinoa, black beans, and lentils. A solution of each protein was prepared by varying its concentration (2.5%, 5.0%, and 10%), the pH (5.0, 7.0, and 9.0), and the incorporation of calcium chloride (0.0% and 1.0%). Each obtained solution was subjected to rheological tests to determine the parameters: consistency index (K), flow behavior (n), the storage (G’) and loss (G’’) modules, and the phase shift angle (δ). The results demonstrate that the incorporation of Ca2+, the shift in protein levels, and the decrease in pH modified the rheological behaviors of proteins, which were also inf...
The objective of this research was to evaluate the effect of the content of cottonseed meal (Goss... more The objective of this research was to evaluate the effect of the content of cottonseed meal (Gossypium hirsutum) and the processing variables on the functional properties and the content of gossypol of an extruded feed for sheep (Ovis aries). The diet was balanced according to the requirements of fattening Dorper sheep breed under 1 year. The extrusion process was optimized using a surface response methodology, with four independent variables: temperature in the last heating zone (120–160°C), moisture content (14–18%), screw speed (120 rpm–180 rpm), and cottonseed meal content (9 g–27 g 100 g−1), in a single screw extruder. The optimal food had 27.25% crude protein, 4.24% crude fat, 12.21% crude fiber, 46.95% nitrogen-free extract, and 9.35% ash. The composition of essential amino acids in the optimal diet was 1.00 g kg−1 of lysine, 1.25 g kg−1 of phenylalanine, 2.04 g kg−1 of leucine, 0.87 g kg−1 of isoleucine, 0.98 g kg−1 of threonine, 1.15 g kg−1 of valine, and 0.65 g kg−1 of his...
Several parameters, including particle size, solvent, temperature, and extraction method, affect ... more Several parameters, including particle size, solvent, temperature, and extraction method, affect phenolic compounds' extraction yield from a plant matrix. Considering the wide availability of sugarcane bagasse (SCB), this study analyzed the effect of different extraction methods and geographical origins on the yield, quality, and antimicrobial activity of phenolic compounds from SCB extracts. Samples from three geographical locations (Veracruz, Mexico; Santa Rosa, Texas, USA; and St. Mary, Louisiana, USA) were analyzed. Extraction was performed using an orbital shaker or ultrasonic bath at various times at a fixed temperature of 50°C, with 90% ethanol or methanol. The highest yield (5.91 mg GAE) was obtained using an orbital shaker for 24 h with 90% methanol as the solvent. HPLC-MS identified desferrioxamine b, baicalein, madecassic acid, and podototarin at different concentrations in all three SCB samples. The antimicrobial activity of these compounds was tested against Escheri...
ABSTRACT Agglutinating compounds are commonly used to improve the physical quality of aquafeeds. ... more ABSTRACT Agglutinating compounds are commonly used to improve the physical quality of aquafeeds. An evaluation was done of the effect of the agglutinating compound sodium alginate on the functional properties of aquaculture fish feed produced by extrusion. Meals containing one of four sodium alginate concentrations (0, 0.5, 1.5 and 2%) were extruded in a simple-screw extruder at 120 °C, 20% moisture content and a 1:1 compression ratio, extruding each treatment in duplicate. Expansion index values ranged from 1.11 to 1.12 with no differences (P > 0.05) between the diets containing sodium alginate. In contrast, the different sodium alginate levels had positive (P < 0.05) effects on water absorption index values (2.24 to 2.79 g/g), water solubility index values (10 to 12.94%), sinking velocity (6 to 8.56 cm/s) and hardness (1.98 to 3.31 N). Maximum hardness (3.31 N) was produced in the 2% sodium alginate diet. The highest sodium alginate level tested (2%) had the most appropriate physical and functional properties for an extruded fish meal-based (62%) aquaculture fish feed.
Extruded snacks were prepared from flour blends made with taro and nixtamalized (TF–NMF) or non-n... more Extruded snacks were prepared from flour blends made with taro and nixtamalized (TF–NMF) or non-nixtamalized maize (TF–MF) using a single-screw extruder. A central composite design was used to investigate the effects of taro flour proportion in formulations (0–100 g/100 g) and extrusion temperatures (140–180 °C) on the following indices: expansion (EI), water solubility (WSI), water absorption (WAI) and fat absorption (FAI). Moreover,
Journal of the Science of Food and Agriculture, 2002
Maize, wheat, amaranth, rice and soybean were screened for protein content. Alcoholsoluble (A1 an... more Maize, wheat, amaranth, rice and soybean were screened for protein content. Alcoholsoluble (A1 and A2) and glutelin (G1 and G2) fractions were isolated and compared in terms of their amino acid and protein compositions. The average proportions of nitrogen content between total alcohol-soluble proteins (TASP) and total glutelins (TGlu) in the pseudocereals amaranth and soybean were about 1.8:26.9 and 14.9:12.3 respectively. In the cereals maize and wheat these proportions were 47.8:33.2 and 44.7:31.2 respectively. The sum of essential amino acids was 47.6 and 60.3 g per 100 g protein in amaranth and soybean respectively. The highest contents of methionine, lysine and arginine were found in the pseudocereals. The relatively high content of essential amino acids shows that pseudocereals could be used as a nutrient substitute for cereals.
International Journal of Food Sciences and Nutrition, 2003
Amaranth, soybean and maize were screened for proteins and their nutritional value. Isopropanol-s... more Amaranth, soybean and maize were screened for proteins and their nutritional value. Isopropanol-soluble protein and buffer-soluble protein fractions were extracted from seeds and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The comparison of the identity and differences between investigated plants was carried out by the obtained SDS-PAGE electrophoretic patterns, and their microstructure was determined by scanning electron microscopy. Electrophoretic patterns of extracted proteins have shown that the main protein subunits were concentrated between 10 and 50 kDa. Variations were found in major fractions and minor bands as well as in the fine structure. The microstructure of pseudocereal and cereal protein fractions was interrelated with the results obtained by their electrophoretic separation. Pseudocereal amaranth can be used as a nutritive substitute of cereal maize in functional foods.
International Journal of Food Sciences and Nutrition, 2009
The aim of this work was to determine the effect on consumer preference of dehydrated apple cubes... more The aim of this work was to determine the effect on consumer preference of dehydrated apple cubes caused by different modifications of a combined drying method. The combined process of convective-osmotic drying with pretreatment in solutions of CaCl(2) and citric acid was taken as the basic process, and was then modified to obtain six different treatments. The factors varied were the osmotic agent, the order of drying processes, and the addition of CaCl(2) to the osmotic solution. The drying kinetics of convective-osmotic treatment and the osmotic-convective process were studied. A sensory evaluation was conducted to determine the effect of these alterations in the drying process on the consumer preference for the product. The convective-osmotic treatment significantly reduced the time of processing. Water loss and solids gain were higher when fructose was used as the osmotic agent in the convective-osmotic process. According to the results of the preference test, only one of the modified processes showed significant preference compared with the basic process.
Food associated diseases pose significant public health threat in the United States. Health risks... more Food associated diseases pose significant public health threat in the United States. Health risks associated with food-borne pathogens drive the need for constant monitoring of food products. An efficient method that can diagnose food-borne pathogens rapidly will be invaluable and in high demand. In this study, we showed the feasibility of a novel rapid detection platform based on fluorescence imaging/detection that combines a user-friendly, portable loop mediated isothermal amplification (LAMP) reaction device and a smartphone-based detection system. The proposed platform was used to detect Staphylococcus aureus which is one of the most important food-borne pathogen especially dairy products. The complete protocol is quicker; the reaction is performed under isothermal conditions and completed in 1 h or less. Experimental results show that LAMP assays were tenfold more sensitive than PCR-based detection. The proposed smartphone detection system was able to detect and quantify LAMP assay samples containing three different concentrations of S. aureus from 10 9 CFU/mL down to 10 3 CFU/mL. The present proof-of-concept study demonstrated that this platform offers a portable, easy to use method for measuring target pathogens with LAMP amplification. Food-borne pathogens are defined as biological agents that cause food-borne illness; they can be either viruses, bacteria and eukaryotes like funguses, protozoa or helminths 1. Every year, the Food and Drug Administration (FDA) reports the outbreaks associated with food-borne pathogens; for instance, in 2020, it reported the contamination of Escherichia coli, Listeria monocytogenes and Cyclospora in clover sprouts, Enoki mushrooms and bagged salad, respectively (FDA 2020). Health risks associated with food-borne pathogens drive the need for constant monitoring of food products. For microbial pathogen detection, the conventional method is bacterial growth on a culture medium then on selective agar; it sometimes involves biochemical or serological testing. This process has some disadvantages because it is time consuming, laborious and detection of non-culturable pathogens is not possible 2. By following the conventional methodology, the detection of E. coli O157 takes around 3 days, Salmonella 4-6 days and Vibrio parahaemolyticus around 7 days 3. For this reason, new techniques emerged which provide faster, more reliable and sensitive results; some of the most widely used are the polymerase chain
Jujube, commonly known as the Chinese date, is a nutritious fruit with medicinal importance. Fres... more Jujube, commonly known as the Chinese date, is a nutritious fruit with medicinal importance. Fresh jujube fruits have a shelf life of about ten days in ambient conditions that can be extended by drying. However, nutrition preservation varies with the drying method and parameters selected. We studied total phenolic content (TPC), proanthocyanidins (PA), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant activities in jujube fruits dried with freeze-drying (FD), convective oven drying (OD) at 50 °C, 60 °C, and 75 °C, and sun drying (SD) with FD as a control. The cultivars used for this study were ‘Capri’ and ‘Xiang’ from Las Cruces in 2019, and ‘Sugarcane’, ‘Lang’, and ‘Sherwood’ from Las Cruces and Los Lunas, New Mexico, in 2020. Freeze-drying had the highest of all nutrient components tested, the best estimates of mature jujube fruits’ nutrient contents. Compared with FD, the majority of PA (96–99%) and vitamin C (90–93%) was lost during SD or OD processes. The retent...
Given consumer trends propelling a movement toward using plant protein in the food industry and s... more Given consumer trends propelling a movement toward using plant protein in the food industry and searching for alternative protein ingredients by the industry, this study aimed to assess the influence of factors such as protein concentration, medium pH, and the presence of a divalent ion (Ca2+) upon the rheological properties such as viscosity change and gel formation of dispersion proteins extracted from quinoa, black beans, and lentils. A solution of each protein was prepared by varying its concentration (2.5%, 5.0%, and 10%), the pH (5.0, 7.0, and 9.0), and the incorporation of calcium chloride (0.0% and 1.0%). Each obtained solution was subjected to rheological tests to determine the parameters: consistency index (K), flow behavior (n), the storage (G’) and loss (G’’) modules, and the phase shift angle (δ). The results demonstrate that the incorporation of Ca2+, the shift in protein levels, and the decrease in pH modified the rheological behaviors of proteins, which were also inf...
The objective of this research was to evaluate the effect of the content of cottonseed meal (Goss... more The objective of this research was to evaluate the effect of the content of cottonseed meal (Gossypium hirsutum) and the processing variables on the functional properties and the content of gossypol of an extruded feed for sheep (Ovis aries). The diet was balanced according to the requirements of fattening Dorper sheep breed under 1 year. The extrusion process was optimized using a surface response methodology, with four independent variables: temperature in the last heating zone (120–160°C), moisture content (14–18%), screw speed (120 rpm–180 rpm), and cottonseed meal content (9 g–27 g 100 g−1), in a single screw extruder. The optimal food had 27.25% crude protein, 4.24% crude fat, 12.21% crude fiber, 46.95% nitrogen-free extract, and 9.35% ash. The composition of essential amino acids in the optimal diet was 1.00 g kg−1 of lysine, 1.25 g kg−1 of phenylalanine, 2.04 g kg−1 of leucine, 0.87 g kg−1 of isoleucine, 0.98 g kg−1 of threonine, 1.15 g kg−1 of valine, and 0.65 g kg−1 of his...
Several parameters, including particle size, solvent, temperature, and extraction method, affect ... more Several parameters, including particle size, solvent, temperature, and extraction method, affect phenolic compounds' extraction yield from a plant matrix. Considering the wide availability of sugarcane bagasse (SCB), this study analyzed the effect of different extraction methods and geographical origins on the yield, quality, and antimicrobial activity of phenolic compounds from SCB extracts. Samples from three geographical locations (Veracruz, Mexico; Santa Rosa, Texas, USA; and St. Mary, Louisiana, USA) were analyzed. Extraction was performed using an orbital shaker or ultrasonic bath at various times at a fixed temperature of 50°C, with 90% ethanol or methanol. The highest yield (5.91 mg GAE) was obtained using an orbital shaker for 24 h with 90% methanol as the solvent. HPLC-MS identified desferrioxamine b, baicalein, madecassic acid, and podototarin at different concentrations in all three SCB samples. The antimicrobial activity of these compounds was tested against Escheri...
ABSTRACT Agglutinating compounds are commonly used to improve the physical quality of aquafeeds. ... more ABSTRACT Agglutinating compounds are commonly used to improve the physical quality of aquafeeds. An evaluation was done of the effect of the agglutinating compound sodium alginate on the functional properties of aquaculture fish feed produced by extrusion. Meals containing one of four sodium alginate concentrations (0, 0.5, 1.5 and 2%) were extruded in a simple-screw extruder at 120 °C, 20% moisture content and a 1:1 compression ratio, extruding each treatment in duplicate. Expansion index values ranged from 1.11 to 1.12 with no differences (P > 0.05) between the diets containing sodium alginate. In contrast, the different sodium alginate levels had positive (P < 0.05) effects on water absorption index values (2.24 to 2.79 g/g), water solubility index values (10 to 12.94%), sinking velocity (6 to 8.56 cm/s) and hardness (1.98 to 3.31 N). Maximum hardness (3.31 N) was produced in the 2% sodium alginate diet. The highest sodium alginate level tested (2%) had the most appropriate physical and functional properties for an extruded fish meal-based (62%) aquaculture fish feed.
Extruded snacks were prepared from flour blends made with taro and nixtamalized (TF–NMF) or non-n... more Extruded snacks were prepared from flour blends made with taro and nixtamalized (TF–NMF) or non-nixtamalized maize (TF–MF) using a single-screw extruder. A central composite design was used to investigate the effects of taro flour proportion in formulations (0–100 g/100 g) and extrusion temperatures (140–180 °C) on the following indices: expansion (EI), water solubility (WSI), water absorption (WAI) and fat absorption (FAI). Moreover,
Journal of the Science of Food and Agriculture, 2002
Maize, wheat, amaranth, rice and soybean were screened for protein content. Alcoholsoluble (A1 an... more Maize, wheat, amaranth, rice and soybean were screened for protein content. Alcoholsoluble (A1 and A2) and glutelin (G1 and G2) fractions were isolated and compared in terms of their amino acid and protein compositions. The average proportions of nitrogen content between total alcohol-soluble proteins (TASP) and total glutelins (TGlu) in the pseudocereals amaranth and soybean were about 1.8:26.9 and 14.9:12.3 respectively. In the cereals maize and wheat these proportions were 47.8:33.2 and 44.7:31.2 respectively. The sum of essential amino acids was 47.6 and 60.3 g per 100 g protein in amaranth and soybean respectively. The highest contents of methionine, lysine and arginine were found in the pseudocereals. The relatively high content of essential amino acids shows that pseudocereals could be used as a nutrient substitute for cereals.
International Journal of Food Sciences and Nutrition, 2003
Amaranth, soybean and maize were screened for proteins and their nutritional value. Isopropanol-s... more Amaranth, soybean and maize were screened for proteins and their nutritional value. Isopropanol-soluble protein and buffer-soluble protein fractions were extracted from seeds and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The comparison of the identity and differences between investigated plants was carried out by the obtained SDS-PAGE electrophoretic patterns, and their microstructure was determined by scanning electron microscopy. Electrophoretic patterns of extracted proteins have shown that the main protein subunits were concentrated between 10 and 50 kDa. Variations were found in major fractions and minor bands as well as in the fine structure. The microstructure of pseudocereal and cereal protein fractions was interrelated with the results obtained by their electrophoretic separation. Pseudocereal amaranth can be used as a nutritive substitute of cereal maize in functional foods.
International Journal of Food Sciences and Nutrition, 2009
The aim of this work was to determine the effect on consumer preference of dehydrated apple cubes... more The aim of this work was to determine the effect on consumer preference of dehydrated apple cubes caused by different modifications of a combined drying method. The combined process of convective-osmotic drying with pretreatment in solutions of CaCl(2) and citric acid was taken as the basic process, and was then modified to obtain six different treatments. The factors varied were the osmotic agent, the order of drying processes, and the addition of CaCl(2) to the osmotic solution. The drying kinetics of convective-osmotic treatment and the osmotic-convective process were studied. A sensory evaluation was conducted to determine the effect of these alterations in the drying process on the consumer preference for the product. The convective-osmotic treatment significantly reduced the time of processing. Water loss and solids gain were higher when fructose was used as the osmotic agent in the convective-osmotic process. According to the results of the preference test, only one of the modified processes showed significant preference compared with the basic process.
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Papers by Efren Delgado