Conventional conservation techniques such as drying, salting or freezing do not allow for preserv... more Conventional conservation techniques such as drying, salting or freezing do not allow for preserving the original characteristics of seaweeds. The present work aims to study the impact of minimal processing, in particular “Modified Atmosphere Packaging” (MAP), on the physicochemical characteristics and food safety of two seaweed species, “laver” (Porphyra umbilicalis) and “sea-lettuce” (Ulva lactuca), stored at 6 °C for 15 days. Different parameters were evaluated using analytical methods, namely the composition of headspace gases, color, texture, microorganisms, and volatile organic compounds (VOCs). The main findings of this study were that the MAP treatment was able to inhibit the respiration rate of minimally processed seaweeds, also preserving their color and texture. There was a remarkable reduction in the microbial load for P. umbilicalis treated under modified and vacuum atmospheres, and U. lactuca exhibited relatively steady values with no notable differences between the tr...
The Cahn, Ingold and Prelog (CIP) system is an essential tool in organic chemistry nomenclature f... more The Cahn, Ingold and Prelog (CIP) system is an essential tool in organic chemistry nomenclature for the specification of stereogenic units. However, over the years, examples of molecules for which such specification was found impossible, ambiguous or inconsistent, have steadily accumulated. Herein, a simple methodology for the comparison of combinations of chiral units, namely to evaluate if two ligands are
Introduction: Seaweeds are well known for their nutritional value [1]. The ALGA4FOOD project [htt... more Introduction: Seaweeds are well known for their nutritional value [1]. The ALGA4FOOD project [https://alga4food.wixsite.com/pt-pt] [2] aims: i) researching new seaweed conservation processes (e.g. lyophilization, pascalization, MAP, etc.) which optimize functional and organoleptic characteristics; ii) develop strategies for its introduction in the Portuguese diet.Materials and methods1: Raw Materials: Seven seweed species (Ulva rigida, Codium tomentosum, Undaria pinnatifida, Saccorhiza polyschides, Gracilaria gracilis, Osmundea pinnatifida, Chondracanthus teedei var. Lusitanicus) were collected in north and central Portugal. Porphyra sp. and Ulva rigida for sensorial analysis were cultivated in an IMTA system. Instrumental Analysis: Each seaweed was frozen with liquid nitrogen and ground. Samples were maintained at −20 °C until microextraction by HS-SPME, using 30 g of fresh seaweed and 104 g of milli-Q water with 30% NaCl (PA). Ulva rigida was also dried and 6.75 g of the dried seaweed and 117 g of the saline solution were used. Compounds extracted were analyzed and identified by GC-MS. Product Development and Sensory Analysis: Dried pastas enriched with U. rigida and Porphyra sp. were developed and affective acceptance tests, using as control a 100% semolina (Triticum durum) pasta, were performed. The panel was composed by 60 untrained testers, and a structured hedonic scale of 1 to 9 points was used for the evaluation of appearance, color, aroma, texture, flavour, overall impression and food suitability. Data was submitted to analysis of variance (ANOVA), and Tukey’s multiple comparison tests.Results: Instrumental analysis: GC-MS identified 57 different organic compounds (167 in total): 28 aldehydes, 4 alcohols; 10 hydrocarbons; 3 ethers; 8 ketones; 4 other functional groups (1 containing sulphur, 2 iodine and 1 bromine). For U. rigida, results showed that the main compounds contributing for its fresh flavour profile (β-ionone and 2,4-decadienal) were different from those for the dried seaweed, meaning that fresh U. rigida has a higher aromatic richness than the dried one. Sensory analysis: The results showed no significant differences between the average values for texture, flavour, overall impression and food suitability. However, the appearance, colour and aroma attributes were significantly different particularly for the control and Porphyra sp. formulations [3].Discussion and conclusions: The exploratory process showed that both instrumental and sensorial analysis, as well as the concepts underlying cooking creativity [3], are of great value for the development of new seaweed food products. GC-MS technique, together with sensory analysis, showed similarities between Undaria pinnatifida and collard greens (Brassica oleracea var. Acephala). Based on this, the seaweed was introduced in the traditional soup “caldoverde”, and preliminary tests showed good acceptance. Sensory analysis of pasta showed that green seaweed, due to their subtle maritime flavour, have a greater potential for cooking applications than the red seaweed [2,3].
Abstract Enzymes are an integral component of modern fruit juice manufacturing, having several ad... more Abstract Enzymes are an integral component of modern fruit juice manufacturing, having several advantages from a commercial and environmental point of view. The enzymes used in the fruit juice industry are primarily mixtures of pectinolytic enzymes. These enzymes break down complex polysaccharides of fruit tissues into simpler molecules. Pectin degradation by enzyme action (enzyme-assisted extraction) leads to an increase in the yield of the extraction of juice from raw material, improves the production efficiency, reduces energy costs and waste, and generates visually attractive final products with improved quality. In this chapter, the discussion is focused on the enzyme-assisted extraction method of fruit juices, particularly in the occurrence and nature of pectic substances in fruits, chemistry of enzymes and their substrates, as well as their biotechnological applications for the processing of different fruits and their effects on the properties of the resulting fruit juices.
International Journal of Biological Macromolecules, Mar 1, 2016
The optimisation of an edible coating based on low acyl (L)/high acyl (H) gellan gum for ready-to... more The optimisation of an edible coating based on low acyl (L)/high acyl (H) gellan gum for ready-to-eat mango bars was performed through a central composite rotatable design (CCRD). The independent variables were the concentration of gellan (L/H90/10) and the concentration of Ca(2+) in the coating solution, as well as the storage time after coating application. The response variables studied were the coating thickness, mango bars firmness, syneresis, and colour alterations. Gellan concentration was the independent variable that most influenced the thickness of the coating. Syneresis was quite low for the conditions tested (<1.64%). Similarly, the colour alterations were low during the entire storage time (ΔE<5). Considering the model predictions, 1.0%wt L/H90/10 with addition of 6mM Ca(2+) could represent the optimal coating formulation for the mango bars. The release of eight volatile compounds from the uncoated and coated mango bars with the selected formulation was analysed by Headspace - Solid Phase Micro Extraction-Gas Chromatography during 9 days of refrigerated storage. This work showed that the coating can improve mango bars sensory characteristics (appearance and firmness) and stability in terms of syneresis, colour and volatiles content during storage increasing the commercial value of the final product.
An analysis of the CIP Sequence Rules was recently published in this journal1. However, further w... more An analysis of the CIP Sequence Rules was recently published in this journal1. However, further work on the implementation of the CIP Rules for computer use suggested that a reformulation of Sequence Rule 1 was required. In this paper this Rule is analyzed and its modification proposed.
Conventional conservation techniques such as drying, salting or freezing do not allow for preserv... more Conventional conservation techniques such as drying, salting or freezing do not allow for preserving the original characteristics of seaweeds. The present work aims to study the impact of minimal processing, in particular “Modified Atmosphere Packaging” (MAP), on the physicochemical characteristics and food safety of two seaweed species, “laver” (Porphyra umbilicalis) and “sea-lettuce” (Ulva lactuca), stored at 6 °C for 15 days. Different parameters were evaluated using analytical methods, namely the composition of headspace gases, color, texture, microorganisms, and volatile organic compounds (VOCs). The main findings of this study were that the MAP treatment was able to inhibit the respiration rate of minimally processed seaweeds, also preserving their color and texture. There was a remarkable reduction in the microbial load for P. umbilicalis treated under modified and vacuum atmospheres, and U. lactuca exhibited relatively steady values with no notable differences between the tr...
The Cahn, Ingold and Prelog (CIP) system is an essential tool in organic chemistry nomenclature f... more The Cahn, Ingold and Prelog (CIP) system is an essential tool in organic chemistry nomenclature for the specification of stereogenic units. However, over the years, examples of molecules for which such specification was found impossible, ambiguous or inconsistent, have steadily accumulated. Herein, a simple methodology for the comparison of combinations of chiral units, namely to evaluate if two ligands are
Introduction: Seaweeds are well known for their nutritional value [1]. The ALGA4FOOD project [htt... more Introduction: Seaweeds are well known for their nutritional value [1]. The ALGA4FOOD project [https://alga4food.wixsite.com/pt-pt] [2] aims: i) researching new seaweed conservation processes (e.g. lyophilization, pascalization, MAP, etc.) which optimize functional and organoleptic characteristics; ii) develop strategies for its introduction in the Portuguese diet.Materials and methods1: Raw Materials: Seven seweed species (Ulva rigida, Codium tomentosum, Undaria pinnatifida, Saccorhiza polyschides, Gracilaria gracilis, Osmundea pinnatifida, Chondracanthus teedei var. Lusitanicus) were collected in north and central Portugal. Porphyra sp. and Ulva rigida for sensorial analysis were cultivated in an IMTA system. Instrumental Analysis: Each seaweed was frozen with liquid nitrogen and ground. Samples were maintained at −20 °C until microextraction by HS-SPME, using 30 g of fresh seaweed and 104 g of milli-Q water with 30% NaCl (PA). Ulva rigida was also dried and 6.75 g of the dried seaweed and 117 g of the saline solution were used. Compounds extracted were analyzed and identified by GC-MS. Product Development and Sensory Analysis: Dried pastas enriched with U. rigida and Porphyra sp. were developed and affective acceptance tests, using as control a 100% semolina (Triticum durum) pasta, were performed. The panel was composed by 60 untrained testers, and a structured hedonic scale of 1 to 9 points was used for the evaluation of appearance, color, aroma, texture, flavour, overall impression and food suitability. Data was submitted to analysis of variance (ANOVA), and Tukey’s multiple comparison tests.Results: Instrumental analysis: GC-MS identified 57 different organic compounds (167 in total): 28 aldehydes, 4 alcohols; 10 hydrocarbons; 3 ethers; 8 ketones; 4 other functional groups (1 containing sulphur, 2 iodine and 1 bromine). For U. rigida, results showed that the main compounds contributing for its fresh flavour profile (β-ionone and 2,4-decadienal) were different from those for the dried seaweed, meaning that fresh U. rigida has a higher aromatic richness than the dried one. Sensory analysis: The results showed no significant differences between the average values for texture, flavour, overall impression and food suitability. However, the appearance, colour and aroma attributes were significantly different particularly for the control and Porphyra sp. formulations [3].Discussion and conclusions: The exploratory process showed that both instrumental and sensorial analysis, as well as the concepts underlying cooking creativity [3], are of great value for the development of new seaweed food products. GC-MS technique, together with sensory analysis, showed similarities between Undaria pinnatifida and collard greens (Brassica oleracea var. Acephala). Based on this, the seaweed was introduced in the traditional soup “caldoverde”, and preliminary tests showed good acceptance. Sensory analysis of pasta showed that green seaweed, due to their subtle maritime flavour, have a greater potential for cooking applications than the red seaweed [2,3].
Abstract Enzymes are an integral component of modern fruit juice manufacturing, having several ad... more Abstract Enzymes are an integral component of modern fruit juice manufacturing, having several advantages from a commercial and environmental point of view. The enzymes used in the fruit juice industry are primarily mixtures of pectinolytic enzymes. These enzymes break down complex polysaccharides of fruit tissues into simpler molecules. Pectin degradation by enzyme action (enzyme-assisted extraction) leads to an increase in the yield of the extraction of juice from raw material, improves the production efficiency, reduces energy costs and waste, and generates visually attractive final products with improved quality. In this chapter, the discussion is focused on the enzyme-assisted extraction method of fruit juices, particularly in the occurrence and nature of pectic substances in fruits, chemistry of enzymes and their substrates, as well as their biotechnological applications for the processing of different fruits and their effects on the properties of the resulting fruit juices.
International Journal of Biological Macromolecules, Mar 1, 2016
The optimisation of an edible coating based on low acyl (L)/high acyl (H) gellan gum for ready-to... more The optimisation of an edible coating based on low acyl (L)/high acyl (H) gellan gum for ready-to-eat mango bars was performed through a central composite rotatable design (CCRD). The independent variables were the concentration of gellan (L/H90/10) and the concentration of Ca(2+) in the coating solution, as well as the storage time after coating application. The response variables studied were the coating thickness, mango bars firmness, syneresis, and colour alterations. Gellan concentration was the independent variable that most influenced the thickness of the coating. Syneresis was quite low for the conditions tested (<1.64%). Similarly, the colour alterations were low during the entire storage time (ΔE<5). Considering the model predictions, 1.0%wt L/H90/10 with addition of 6mM Ca(2+) could represent the optimal coating formulation for the mango bars. The release of eight volatile compounds from the uncoated and coated mango bars with the selected formulation was analysed by Headspace - Solid Phase Micro Extraction-Gas Chromatography during 9 days of refrigerated storage. This work showed that the coating can improve mango bars sensory characteristics (appearance and firmness) and stability in terms of syneresis, colour and volatiles content during storage increasing the commercial value of the final product.
An analysis of the CIP Sequence Rules was recently published in this journal1. However, further w... more An analysis of the CIP Sequence Rules was recently published in this journal1. However, further work on the implementation of the CIP Rules for computer use suggested that a reformulation of Sequence Rule 1 was required. In this paper this Rule is analyzed and its modification proposed.
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