Flavor-enhancing Properties Research Articles

Applying productivity and phytonutrient profile criteria in modelling species selection of microgreens as Space crops for astronaut consumption.

Long-duration missions in outer Space will require technologies to regenerate environmental resources such as air and water and to produce food while recycling consumables and waste. Plants are considered the most promising biological regenerators to accomplish these functions, due to their complementary relationship with humans. Plant cultivation for Space starts with small plant growth units to produce fresh food to supplement stowed food for astronauts' onboard spacecrafts and orbital platforms. The choice of crops must be based on limiting factors such as time, energy, and volume. Consequently, small, fast-growing crops are needed to grow in microgravity and to provide astronauts with fresh food rich in functional compounds. Microgreens are functional food crops recently valued for their color and flavor enhancing properties, their rich phytonutrient content and short production cycle. Candidate species of microgreens to be harvested and eaten fresh by crew members, belong to the families Brassicaceae, Asteraceae, Chenopodiaceae, Lamiaceae, Apiaceae, Amarillydaceae, Amaranthaceae, and Cucurbitaceae. In this study we developed and applied an algorithm to objectively compare numerous genotypes of microgreens intending to select those with the best productivity and phytonutrient profile for cultivation in Space. The selection process consisted of two subsequent phases. The first selection was based on literature data including 39 genotypes and 25 parameters related to growth, phytonutrients (e.g., tocopherol, phylloquinone, ascorbic acid, polyphenols, lutein, carotenoids, violaxanthin), and mineral elements. Parameters were implemented in a mathematical model with prioritization criteria to generate a ranking list of microgreens. The second phase was based on germination and cultivation tests specifically designed for this study and performed on the six top species resulting from the first ranking list. For the second selection, experimental data on phytonutrients were expressed as metabolite production per day per square meter. In the final ranking list radish and savoy cabbage resulted with the highest scores based on their productivity and phytonutrient profile. Overall, the algorithm with prioritization criteria allowed us to objectively compare candidate species and obtain a ranking list based on the combination of numerous parameters measured in the different species. This method can be also adapted to new species, parameters, or re-prioritizing the parameters for specific selection purposes.

Purification and characterization of glutaminase from Iraqi fruit of ‎ Capsicum annuum

L-glutaminase has recently attracted much attention due to its medicinal and industrial potential. It's an antileukemic drug with flavor-enhancing properties when used in fermented foods manufacturing. The enzyme purification was determined by ammonium sulfate precipitation, Ion exchange chromatography and gel filtration chromatography with estimating glutaminase activity and characterization of purified glutaminase in several parameters such as substrate concentration and reaction time pH, and temperature influence in this study. As a result, glutaminase is purified in three steps: ammonium sulfate precipitation with 30% saturation, DEAE-Cellulose and Sephacryl S-200. The specific activity increased to 85 U/mg protein with 4 folds of purification and 18% enzyme recovery. When glutaminase was incubated in the presence of 150 millimolar glutamine at thirty-five centigrade for thirty minutes, the enzyme reached its maximal activity of 1.8 u/ml, in the presence of a 0.05 Molar potassium phosphate buffer solution, at pH 8. Keywords: Capsicum annum, glutaminase, enzyme activity, glutaminase purification

Fatty acid composition and antioxidant activity of Angelica glauca and Chenopodium album seed extracts from Kashmir

Angelica glauca Edgew. and Chenopodium album Linn. are medicinally important plants with aromatic, nutritious and flavor-enhancing properties. In this study the fatty acid composition of petroleum ether seed extracts (PE) of processed plants were analyzed by gas chromatography-mass spectrometry (GC-MS). The PE consisted mainly of unsaturated fatty acids, such as petroselinic acid 74.26% and oleic acid 7.37% for A. glauca and linoleic acid 53.05% and oleic acid 20.74% for C. album. The de-fatted seed extracts were screened for their antioxidant activities using 2,2-di-phenyl-1-picrylhydrazyl (DPPH), nitroblue tetrazolium (NBT), hydrogen peroxide (H2O2) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. Almost all the assays resulted in defatted seed extracts showing powerful radical scavenging activity. These findings suggest that the processed plants could be used as ingredients (as a source of natural antioxidants and unsaturated fatty acids) for the formulation of functional foods.

Probiotic potential of lactic acid bacteria isolated from traditionally fermented legume products of Western Kenya

Fermentation as a processing technique has been used for a long time by people of Western Kenya to improve the quality of raw food material. During fermentation, lactic acid bacteria (LAB) synthesize vitamins and minerals, produce biologically active peptides with enzymes such as proteinase and peptidase, and remove some ant-nutrients. The medicinal and i¬‚avor enhancing properties of fermented foods are due to the presence of probiotics. This study aims at isolating and biochemically characterizing potential probiotic lactic acid bacteria from spontaneously fermented legume-based products from two locations in Vihiga County; Emuhaya and Mbale, Kenya. The results from the findings are presumptive indicator of probiotic bacteria in fermented legumes. RC0PU2, SB0PU3 and CP0PU1 isolated form Emuhaya can survive at low pH of 2 while SB0PU3 and CP0PU1 in addition can survive a salt concentration of 3%. SB0PU3 and CPOPU2 and RC0PU2, SB0PU2 and CPOPU3 can grow at high temperature of 45°C. RC0PU2, SB0PU2, GG0PU1, CP0PU1 and CPOPU2 can tolerate a salt concentration of 3%. Only two isolates RCOPU2 and CPOPU2 isolated from Mbale samples survived at the pH of 2. The findings from this study indicated that fermented legumes are potential sources of probiotics with unique characteristics. Key words: Probiotic potential, legumes, lactic acid bacteria.

Application of Non-Saccharomyces Yeasts Isolated from Kombucha in the Production of Alcohol-Free Beer

Alcohol-free beer (AFB) is no longer just a niche product in the beer market. For brewers, this product category offers economic benefits in the form of a growing market and often a lower tax burden and enables brewers to extend their product portfolio and promote responsible drinking. Non-Saccharomyces yeasts are known for their flavor-enhancing properties in food fermentations, and their prevailing inability to ferment maltose and maltotriose sets a natural fermentation limit and can introduce a promising approach in the production of AFB (≤0.5% v/v). Five strains isolated from kombucha, Hanseniaspora valbyensis, Hanseniaspora vineae, Torulaspora delbrueckii, Zygosaccharomyces bailii and Zygosaccharomyces kombuchaensis were compared to a commercially applied AFB strain Saccharomycodes ludwigii and a Saccharomyces cerevisiae brewer’s yeast. The strains were characterized for their sugar utilization, phenolic off-flavors, hop sensitivity and flocculation. Trial fermentations were analyzed for extract reduction, ethanol formation, pH drop and final beers were analyzed for amino acids utilization and fermentation by-products. The performance of non-Saccharomyces strains and the commercial AFB strain were comparable during fermentation and production of fermentation by-products. An experienced sensory panel could not discriminate between the non-Saccharomyces AFB and the one produced with the commercial AFB strain, therefore indicating their suitability in AFB brewing.

Consumer acceptance of dishes in which beef has been partially substituted with mushrooms and sodium has been reduced

We tested the hypothesis that because of their flavor-enhancing properties, mushrooms could be used as a healthy substitute for meat and a mitigating agent for sodium (salt) reduction without reduction in sensory appeal among consumers. In a fully-randomized design for each product, 147 consumers evaluated blind two carne asada and six taco blend recipes in which beef had been partially substituted with mushrooms and/or salt had been reduced by 25%, for overall liking, liking of appearance, flavor, texture and mouth feel on the 9-point hedonic scale, and adequacy of level of saltiness, spiciness and moistness on 5-point just-about-right (JAR) scales. Overall consumer acceptance of the carne asada, and liking for its appearance, flavor and texture/mouth feel decreased significantly when half the steak was substituted with mushrooms. The taco blend recipes with full sodium were also liked more overall than those with 25% less sodium. But there was no significant difference in overall liking among the three full-salt recipes, nor among the three reduced-salt recipes, indicating that across the consumer population we tested, acceptance of the mushroom-containing recipes was on par with that of the 100% beef recipe. The preference mapping analysis of the overall liking ratings of the taco blends uncovered four preference segments, two of which, representing a majority of the consumers, gave higher acceptance scores to the mushroom-substituted recipes. Furthermore, the largest preference segment liked the full- and reduced-sodium recipes equally, and another liked the reduced-sodium recipes significantly more. This research demonstrates that through their flavor enhancing properties, mushrooms can be used successfully to substitute for beef and even possibly mitigate sodium reduction without significant change in acceptance for a majority of consumers.

PH‐Dependent hydrolase, glutaminase, transpeptidase and autotranspeptidase activities of Bacillus subtilis γ‐glutamyltransferase

γ-Glutamyltransferases (γ-GTs) are heterodimeric enzymes that catalyze the transfer of a γ-glutamyl group from a donor species to an acceptor molecule in a transpeptidation reaction through the formation of an intermediate γ-glutamyl enzyme. In our search for a γ-GT from a generally recognized as safe microorganism suitable for the production of γ-glutamyl derivatives with flavor-enhancing properties intended for human use, we cloned and overexpressed the γ-GT from Bacillus subtilis. In this study, we report the behavior of B. subtilis γ-GT in reactions involving glutamine as the donor compound and various acceptor amino acids. The common thread emerging from our results is a strong dependence of the hydrolase, transpeptidase and autotranspeptidase activities of B. subtilis γ-GT on pH, also in relation to the pKa of the acceptor amino acids. Glutamine, commonly referred to as a poor acceptor molecule, undergoes rapid autotranspeptidation at elevated pH, affording oligomeric species, in which up to four γ-glutamyl moieties are linked to a single glutamine. Moreover, we found that D-glutamine is also recognized both as a donor and as an acceptor substrate. Our results prove that the B. subtilis γ-GT-catalyzed transpeptidation reaction is feasible, and the observed activities of γ-GT from B. subtilis could be interpreted in relation to the known ability of the enzyme to process the polymeric material γ-polyglutamic acid.

Probiotic fermented foods for health benefits

The history of fermented foods used by humans can be traced back to centuries. The medicinal as well as flavor enhancing properties of fermented foods are mainly due to the presence of bacteria known as probiotics. Probiotics aid in digestion and nutrient assimilation. These bacteria are also known for their beneficial effects for the immune system and health. Many of them produce antimicrobial bioactive molecules that make them effective biopreservatives and produce nutraceuticals to create functional foods with increased bioavailability of nutrients. Thus, these lactic acid bacteria have undeniable favorable effects. This review will summarize the health benefits of probiotic fermented foods.

Changes in Chemical and Sensory Properties of Migaki‐Nishin (Dried Herring Fillet) during Drying

Migaki-nishin is a Japanese term that refers to dried herring fillets. It is widely consumed in Japan due to its characteristic flavor enhancing properties. This study was conducted to investigate the changes in chemical and sensory properties of migaki-nishin during drying. Chemical analyses showed that extractive nitrogen and amount of peptides increased significantly (P < 0.05) up to the 8th day of drying and then slightly decreased by the 10th day. Glutamic acid, alanine, glycine, and histidine were the most abundant free amino acids and the largest increase was found in samples dried for 10 d. A decrease in Hunter's L* value (lightness) and increase in b* value (yellowness) as well as browning intensity suggested that nonenzymatic browning occurred in migaki-nishin during drying. Fluorescence spectrophotometric determination also revealed that Maillard reactions progressed throughout the drying period. In addition, available lysine content and free amino groups decreased significantly (P < 0.05) as drying progressed. Sensory evaluation showed that addition of water-soluble extracts to Japanese noodle soup (mentsuyu) linearly enhanced the flavor characteristics such as thickness, mouthfulness, and continuity with the increased length of drying time. These results suggest that during the drying period, proteolysis as well as Maillard reaction products increased markedly, which might contribute to the characteristic taste and flavor of migaki-nishin.

Comprehensive Study of the “Beefy Meaty Peptide”

The octapeptide Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala, also called “beefy meaty peptide” (BMP), is supposed in the literature to play a key role in the taste of meat. A procedure allowing its detection in beef extract down to a level of 1 ppm was developed using sample enrichment by solid-phase extraction and on-line detection by electrospray LC/MS. It is shown that detectable levels of BMP do not occur naturally, in beef digests, or in cooked or grilled beef. Furthermore, a thorough sensory evaluation showed that BMP, when tasted in water, is described as having a strong acid and astringent taste. Tasting in beef stock, both with and without added NaCl or monosodium glutamate, revealed that the compound has little or no detectable flavor or flavor enhancing properties. Therefore, BMP cannot be considered as a flavor carrier or a potential flavor enhancer. Keywords: Peptide; flavor; meat; taste; monosodium glutamate; beefy meaty peptide; liquid chromatography; mass spectrometry

A report of the proceedings of an MSG workshop held August 1991.

This report of the proceedings of a workshop on monosodium glutamate (MSG) represents the output of an exchange of scientific information, discussed and debated, by a group of experts representing a variety of disciplines. Experts in the areas of food science, potential adverse reactions to foods, pharmacology, neuroscience, biochemistry, nutrition, pediatrics, and anatomy reviewed the current scientific literature relative to the safe use of MSG in foods. These proceedings supplement the extensive literature compiled by various prestigious international expert committees since the flavor-enhancing properties of MSG were identified around the turn of the century,

Phosphohydrolases and the production of 5′‐nucleotides by direct fermentation

AbstractA major problem involved in the direct fermentation of nucleotides is their breakdown by phosphohydrolases. Thus, adenine auxotrophs of most microorganisms produce hypoxanthine and/or inosine rather than inosine 5′‐monophosphate (IMP) while guanine auxotrophs excrete xanthosine rather than xanthosine 5′‐monophosphate (XMP). Examination of a Bacillus subtilis mutant producing hypoxanthine plus inosine revealed at least four phosphohydrolases, three of which could attack nucleotides. Even when the extracellular nucleotide phosphohydrolase was inhibited by Cu+2 and its surface‐bound alkaline phosphohydrolase was repressed and inhibited by inorganic phosphate, or removed by mutation, the breakdown products were still the only products of fermentation. Under these conditions, the third enzyme, a surface‐bound non‐repressible nucleotide phosphohydrolase was still active. It appears, at least in B. subtilis, that excretion is dependent upon breakdown by this enzyme and if hydrolysis does not occur, excretion of purine nucleotides is feedback inhibited by the resultant high intracellular IMP concentration. Corynebacterium glutamicum mutants, on the other hand, can excrete intact nucleotides, and direct fermentations for IMP, XMP, and GMP have been described. An examination of phosphohydrolases in a GMP‐producing culture revealed no extracellular or surface enzymes. Disruption of the cells resulted in liberation of cellular phosphohydrolase activity with a substrate specificity remarkably similar to the flavorenhancing properties of the 5′‐nucleotides. The order of decreasing susceptibility was GMP, IMP, XMP; AMP was not attacked.