Umami Flavor Research Articles

Analysis of meaty aroma and umami taste in thermally treated yeast extract by means of sensory-guided screening

YE (yeast extract) has been widely used in the flavor industry as the source to produce the high-quality meaty and umami flavors. It is because YE is rich in the savory and mellow constituents and is important precursors to generate aromas via thermal treatment. This study aims to investigate the change of meaty aroma and umami taste in the hydrolyzed YE during the thermal treatment. In this study, gas chromatography–olfactometry-mass spectrometer (GC-O-MS) was employed to detect the aroma-active compounds, and systematic approaches was used for the taste-active umami proteolytics separation and detection. The reaction conditions of two optimal samples, YE-A and YE-B, were as follows: the reaction time (A) was 90 min, the reaction temperature (B) was at 115 °C, the concentration of YE solution (C) was 0.4 g/mL, and pH (D) was 5.5 and 6.0, respectively. The GC-O-MS results show YE-A contains 31 and YE-B contains 29 key aroma-active compounds, and the priorities of four factors are both C > B > D > A. The key aroma-active compounds that contributed to meaty flavor were both 3-(methylthio)propanal (cooked potato-like), dihydro-5-pentyl-2(3H)-furanone (coconut-like, peach-like), 2-ethyl-3,5-dimethyl pyrazine (potato-like) etc. with OAVs greater than 1. The Q-TOF–MS/MS results show that YE-A contained five umami peptides, which were Ala-Asp-Ala, Pro-Gly-Asp, Glu-Met-His, Gln-Pro-Ser and Val-Glu-His; whereas YE-B contained four umami peptides, which were Glu-Asp, Pro-Ser-Gly, Ala-Glu-Ala, and Gly-Gly-Pro-Gly.

Clinical Role of Extraoral Bitter Taste Receptors.

Humans can recognise five basic tastes: sweet, sour, salty, bitter and umami. Sour and salty substances are linked to ion channels, while sweet, bitter and umami flavours are transmitted through receptors linked to the G protein (G protein-coupled receptors; GPCRs). There are two main types of GPCRs that transmit information about sweet, umami and bitter tastes—the Tas1r and TAS2R families. There are about 25 functional TAS2R genes coding bitter taste receptor proteins. They are found not only in the mouth and throat, but also in the intestines, brain, bladder and lower and upper respiratory tract. The determination of their purpose in these locations has become an inspiration for much research. Their presence has also been confirmed in breast cancer cells, ovarian cancer cells and neuroblastoma, revealing a promising new oncological marker. Polymorphisms of TAS2R38 have been proven to have an influence on the course of chronic rhinosinusitis and upper airway defensive mechanisms. TAS2R receptors mediate the bronchodilatory effect in human airway smooth muscle, which may lead to the creation of another medicine group used in asthma or chronic obstructive pulmonary disease. The discovery that functionally compromised TAS2R receptors negatively impact glucose homeostasis has produced a new area of diabetes research. In this article, we would like to focus on what facts have been already established in the matter of extraoral TAS2R receptors in humans.

The effect of moderate pulsed electric fields on autolysis of Saccharomyces cerevisiae and the amino acid content in autolysates

SummaryThe effect of moderate pulsed electric fields (MPEF) strength on autolysis of Saccharomyces cerevisiae was evaluated in this study. After exposure to MPEF with intensity of 7 kV cm−1 for 4 ms, the integrity of the cell wall was obviously destroyed and the inactivation of S. cerevisiae reached 99.43%. During the subsequent 42‐h autolysis process, the release of free α‐amino nitrogen of MPEF‐treated cells, as well as extracellular protease activity, was significantly (P < 0.05) higher than that of untreated cells. Moreover, exposure to 7 kV cm−1 led to an increase of the total amino acid of 149.36%. In particular, the content of aspartic acid and glutamic acid which are important umami flavour precursors increased by 232.55% and 209.40%, respectively. These results indicate that MPEF will be an effective method to accelerate autolysis of S. cerevisiae for obtaining high‐quality yeast extract as flavour enhancers and nutrition supplements.

The R2R3-MYB transcription factor CsMYB73 negatively regulates l-Theanine biosynthesis in tea plants (Camellia sinensis L.)

l-Theanine, a non-proteinaceous amino acid abundantly present in tea (Camellia sinensis), contributes to the umami flavor of tea and has beneficial effects on human health. While key l-theanine biosynthetic genes have been well documented, their transcriptional regulation remains poorly understood. In this study, we determined the l-theanine contents in tea leaves of two cultivars at three developmental stages and investigated the expression patterns of the l-theanine biosynthetic genes CsGS1 and CsGS2. Additionally, we identified an R2R3-MYB transcription factor, CsMYB73, belonging to subgroup 22 of the R2R3-MYB family. CsMYB73 expression negatively correlated with l-theanine accumulation during leaf maturation. We found that CsMYB73, as a nuclear protein, binds to the promoter regions of CsGS1 and CsGS2 via MYB recognition sequences and represses the transcription of CsGS1 and CsGS2 in tobacco leaves. Collectively, our results demonstrate that CsMYB73 is a transcriptional repressor involved in l-theanine biosynthesis in tea plants. Our findings might contribute to future tea plant breeding strategies.

Replacing cottonseed meal and sorghum grain with corn dried distillers' grains with solubles in lamb feedlot diets: carcass, trained sensory panel, and volatile aroma compounds traits.

In a randomized design study, lambs were individually fed with ad libitum access to 70.9% concentrate diets for 56 d in individual pens. The positive control diet (CNTL) contained cottonseed meal (CSM), sorghum grain, and cottonseed hulls, but no dried distillers' grains with solubles (DDGS). Four treatment diets were similar to CNTL but did not contain CSM. Corn DDGS replaced 0% (0DDGS), 33% (33DDGS), 66% (66DDGS), or 100% (100DDGS) of the sorghum grain in the treatment diets. At 48-h postmortem, the longissimus muscle (LM) was removed from the carcass, cut into chops, frozen, thawed, cooked, and evaluated by a trained sensory panel. Lambs fed CNTL were compared with 0DDGS using contrasts and linear and quadratic effects were evaluated among the four DDGS diets. Lambs fed CNTL had greater (P ≤ 0.03) hot carcass weight (HCW) and LM area than lambs fed 0DDGS. As DDGS incrementally replaced sorghum grain, marbling linearly decreased (P = 0.03), LM area tended to linearly increase (P = 0.06), and skeletal maturity tended to linearly decrease (P = 0.06). As DDGS incrementally replaced sorghum grain, flavor attributes quadratically increased to 33DDGS then decreased (brown, roasted, umami; P ≤ 0.03), quadratically decreased to 33DDGS then increased (metallic; P = 0.004), or linearly decreased (lamb flavor identity; P = 0.03). Volatile aroma compounds 2-(hexyloxy)-ethanol decreased and 2,3-octanedione and methyl pyrazine increased quadratically with an increase in DDGS (P < 0.05). Additionally, 2-heptenal, heptanal, and 2-pentyl furan increased linearly, while 2-butanone decreased linearly as DDGS increased in the diet (P < 0.05). Results indicate that carcass and sensory characteristics and volatile aroma compounds are not negatively affected, in fact brown, roasted, and umami flavors are enhanced, when 33% DDGS replaces CSM and sorghum grain in Dorper lamb feedlot diets.

Effects of glutinous rice protein components on the volatile substances and sensory properties of Chinese rice wine.

The content of protein components of glutinous rice significantly affects the quality of Chinese rice wine. Therefore, the effects of protein components on the quality of Chinese rice wine were investigated by adding the exogenous proteins glutelin and albumin individually or in combination RESULTS: Compared with the control, the samples with increased glutelin components exhibited improved formation of numerous alcohol esters with alcoholic and fruity representatives. The promotion rates of glutelin to total alcohols and total esters were 18% and 99%, respectively. The amount of 4-vinylguaiacol characterized by a spicy, smoky odor was reduced to 40%. Correlation analysis between chemical composition and sensory characteristics showed a significant positive correlation between umami and amino nitrogen (r = 0.935) and total amino acid content (r = 0.729). The bitterness of Chinese rice wine was related to the change of alcohol content (r = 0.689) and total soluble solid (r = 0.904). Sensory analysis revealed that the increase of the glutelin component of Chinese rice wine increased its alcoholic, fruity, and honey-like features, as well as its umami, acidity and bitterness. The increase also reduced the caramel-like, herb-like, and smoky sensory characteristics of Chinese rice wine and its Qu aroma and sweetness CONCLUSION: The protein content of glutinous rice significantly affects the quality of rice wine. The Glutelin has a significant relationship with fruity, honey, and umami flavors; the albumin has a significant relationship with medicinal, bitter, and astringent flavors. Therefore, reasonable adjustment of the glutelin content of glutinous rice can effectively improve the sensory quality of rice wine. © 2020 Society of Chemical Industry.

A comparative study of sensory quality of sie reuboh (an Acehnese cooked meat) based on its cooking ware

Sie reuboh is a traditional festive cuisine from Aceh Besar district – Aceh Province. Sie reuboh named by Acehnese for a 2:1 comparison of red-meat and separated beef tallow boiled with palm vinegar and blended spices. It reported having a long shelf life, exquisite of taste and flavor. Normally, Acehnese cooks this cuisine with traditional clay pot. As cooking utensil, clay pot is vulnerable to breakage and has slow heat propagation compared to stainless steel pot which has long usage and good heat conductor. This study aims to compare the quality of produced siereuboh based on its sensory quality (Hedonic and Qualitative Descriptive Analysis = QDA) and consumer acceptance by hedonic test. Sie reuboh was cooked in two types of cooking ware (earth clay pot and stainlesssteelpot) in four times repetitions. The obtained data is statistical analyzed with ANOVA and DMRT. The results showed that sie reuboh cooked with stainless steel pot is preferable in terms of color, aroma, flavor (P≤0,01) than one cooked with clay pot. Furthermore, the QDA showed that from ten examined attributes, brightness, sour and spicy aroma and umami flavor of sie reuboh cooked with stainless steel has higher notes (P≤0,01) than other treatment. As conclusion, it can be stated that stainless steel provides sie reuboh with better sensory properties and higher consumer liking. A post-publication change was made to this article on 11 Mar 2020 to correct the conference title in the PDF header.

Effect of the addition of edible mushroom flours ( Agaricus bisporus and Pleurotus ostreatus ) on physicochemical and sensory properties of cold‐stored beef patties

The characteristics of beef patties with partial replacement of fat and salt by the addition of 2.5 and 5.0% edible mushroom (Agaricus bisporus and Pleurotus ostreatus) flours were studied during cold storage. Besides the reduction of fat and sodium content, the addition of flours significantly improved the dietary fiber and protein contents (from 17.53% to 19.23% with 5% of A. bisporus flour). Hardness, gumminess, and chewiness values were not significantly different from control samples, while springiness and cohesiveness significantly decreased. The addition of flours modified the color, although odor and taste were the attributes most affected. Burgers with 2.5% flour presented acceptable sensory parameters, so that they could be an acceptable option to provide a reduction of fat and salt. During cold storage, formulations were rapidly spoiled because of the microbial growth and oxidation processes, but a small antimicrobial effect against Pseudomonas was observed when mushroom flours were added. PRACTICAL APPLICATIONS: The inclusion of 2.5% of mushroom flour from Agaricus bisporus and Pleurotus ostreatus is a feasible alternative to improve the nutritional profile of beef patties enriching the fiber content and reducing the fat and salt content (25% and 50%, respectively) with an acceptable sensory profile. Higher percentages of flour would deeply affect sensory properties to a consumer not accustomed to the intense umami flavor. The inclusion of mushroom flour in beef patties represents also an opportunity for the mushroom producers adding value to the product by simple drying processes.

Sensory Descriptive Attributes of Grass and Grain-Fed Australian Beef Longissimus Lumborum after Extended Wet-Aging Periods

ObjectivesThe objective of this study was to evaluate the effects of extended wet-aging on the beef flavor profile of grass and grain-fed Australian strip loins.Materials and MethodsStrip loins (HAM 2140) were collected from grass and grain finished cattle (n = 50) at a commercial abattoir near Brisbane, Australia. Subprimals were portioned into sections and assigned randomly to 1 of 3 postmortem aging periods (45, 70, or 135 d). Portions were individually vacuum packaged and shipped refrigerated (0–4°C) to Texas Tech University in Lubbock, TX. Upon arrival, the strip loin sections were sorted into respective aging groups of 45D, 70D, and 135D and stored at 1–2°C. On each respective day, sections were fabricated into 2.54-cm steaks, vacuum packaged and frozen (–21°C). Electric clamshell grills were used to cook thawed (held at 2–4°C for 24 h) steaks to a medium degree of doneness (71°C); cooked temperatures were recorded. Steaks were cut into cubes and evaluated by trained panelists (n = 6) for descriptive sensory attributes using a 100-mm anchored line scales (0 = slight, 50 = moderate and 100 = strong).ResultsThe sour flavor was the only trait where an interaction between diet and postmortem aging was detected (P &lt; 0.01). Samples aged 135 d from both grass and grain were similarly (P &gt; 0.05) scored with a stronger (P &lt; 0.05) sour flavor than all other treatment combinations, which did not differ (P &gt; 0.05). Aging impacted (P ≤ 0.01) beef flavor ID, liver-like, metallic, rancid, green-hay, umami, and bitter flavors, as well as overall juiciness and overall tenderness. For beef flavor ID, 45D aging resulted in the greatest intensity (P &lt; 0.05), while 70D samples were intermediate, and 135D samples were the least intense. For liver-like, metallic, rancid, green-hay, and bitter flavors, 135D samples had the strongest flavor, while 70D samples were intermediate, and 45D samples had the weakest flavor intensity (P &lt; 0.05). For umami, 45D samples had stronger (P &lt; 0.05) umami flavor than 135D samples, but 70D samples did not differ from either 45D or 135D (P &gt; 0.05). Panelists rated 70D and 135D samples juicier (P &lt; 0.01) than 45D samples, but 70D and 135D did not differ (P &gt; 0.05). For overall tenderness, panelists rated 135D samples more tender (P &lt; 0.05) than 45D and 70D, which were similar (P &gt; 0.05). Diet impacted (P &lt; 0.05) bloody/serumy, liver-like, green-hay, and bitter flavors. For bloody/serumy and liver-like, the grain fed treatments resulted in greater (P &lt; 0.05) flavor intensity than grass fed treatments. However, grass fed samples had stronger (P &lt; 0.05) green-hay and bitter flavors compared to grain fed samples. Diet and aging had no effect (P &gt; 0.05) on fat-like or sweet flavors.ConclusionExtending postmortem aging of Australian beef strip loins from 45 to 135 d resulted in decreased beef and umami flavors, along with concurrent increased detection of off-flavors, such as liver-like, rancid, and sour. Diet influenced fewer flavor traits than postmortem aging, but grass-fed samples still had stronger green-hay flavor, as would be expected. Based on these results, aging beef strip loins 135 d is not recommended based on reduced beef flavor and increased off-flavor detection.

Metabolomic Predictors for Flavor Potential of Beef Steaks Differing in Quality Grade, Aging Time, and Degree of Donenesss

ObjectivesThe objective of this project was to explore metabolomic predictors that could determine the potential of beef strip loin steaks differing in quality grade, aging time, and degree of doneness to develop positive flavors.Materials and MethodsUSDA Select (n = 18) and USDA Upper 2/3 Choice (n = 18) beef strip loins (IMPS 180) were collected from a processing plant. Loins were halved, and each half was wet aged for either 10 or 20 d in a cooler kept at 2°C. After aging, loins were cut into 2.54 cm steaks, individually vacuum packaged and stored in a freezer at –40°C. Prior to cooking steaks were thawed in a 4°C cooler for 12 to 24 h. Steaks were cooked on a flat top griddle set to 204.4°C (± 11.1°C) to one of three degrees of doneness: 63°C (medium rare), 71°C (medium) or 80°C (medium well). A six-member expert trained descriptive attribute panel was trained on 16 major attributes, 4 other attributes, and 3 texture attributes from the beef lexicon for 6 d prior to testing. Panelists were trained to scale each attribute on a sixteen-point intensity scale (0 = none, 15 = extremely intense). Panelists were served two random, representative cubes (1.3 cm × 1.3 cm × steak thickness) from each steak in a plastic souffle cup labeled with a random three-digit code. Panelists were seated in a breadbox-style booth under red lighting to eliminate degree of doneness bias. Portions from one raw steak from Quality Grade (QG) × aging combination from each loin was used for high performance liquid chromatography (HPLC) analysis. Samples were homogenized and extracted with a water/acetonitrile solution before being filtered. The lipid fraction was removed via solid phase extraction. Samples were then centrifuged and injected into the HPLC. Data was analyzed as a factorial arrangement of a completely randomized design.ResultsUSDA Choice steaks had more intense beef flavor identity, brown, roasted, fat-like, salty, sweet, sour, umami, buttery, and overall sweet flavors and were juicier and more tender compared to USDA Select steaks, which were more intense in metallic and bitter flavors (P &lt; 0.05). Steaks aged for 20 d were juicer and more tender than 10-d aged steaks (P &lt; 0.05). However, 20-d aged steaks also had more intense sour, liver-like, and musty earthy/humus flavors and a less intense brown flavor compared to 10 d aged steaks (P &lt; 0.05). Steaks cooked to 80°C had more intense beef identity, brown, roasted, and umami flavors than steaks cooked to a lower degree of doneness (P &lt; 0.05). Steaks cooked to either 63°C or 71°C had more intense bloody, metallic, and sour flavors and are juicier and more tender than steaks cooked to the higher degree of doneness (P &lt; 0.05). The HPLC analysis of raw steak samples indicated a total of 54 compounds appeared in at least 80% of one treatment. Additionally, there were 2 peptides and 1 sugar that were significantly (P &lt; 0.05) upregulated in the Choice, 20-d-aged strip loins. Additionally, 14 compounds were identified that were shared across all four QG × aging combinations. This included 11 peptides, 2 phospholipids, and 1 heterocyclic aromatic hydrocarbon.ConclusionThese compounds could be indications of the potential for steaks to form positive flavor attributes found in USDA Choice steaks and 20-d aged steaks as described by trained panel analysis.

Influence of Cook Method and Degree of Doneness on Beef Flavor Attributes in Round Steaks

ObjectivesIt has been well established that cooking method, marbling level, and cooked internal temperature endpoint affect beef flavor, the most important driver of consumer acceptance. However, beef cuts respond differently to cooking method and cooked internal temperature endpoint based on their inherent chemical characteristics.Materials and MethodsTreatments were: beef cuts (inside round, bottom round, and eye of round); USDA beef quality grade (upper two-thirds Choice and Select); cooking methods (pan grill, stir fry, stew no marinade, stew marinade, and roast); and internal cook temperature endpoints (58, 70, and 80°C). The pan grill cook method included 0.25 and 0.75 in samples from each muscle type. The stir fry cook method treatment was limited to 0.25 in cuts, which were cut into 1.00 in strips prior to cooking. The marinated and non-marinated stew cook method treatments included 0.25 and 0.75 in samples from each muscle. These samples were then cut into 0.25 × 1.00 × 1.00 in and 0.75 × 1.00 × 1.00 in samples prior to cooking. Stew marinated samples were marinated with 118 mL water, 90 mL lemon juice, 30 mL canola oil, 5 mL salt, and 2.5 mL pepper. Two lb roasts were cut from bottom round and eye of round subprimals and inside round subprimals were cut into 2.00 in roasts prior to cooking. An expert descriptive beef flavor and texture attribute panel evaluated each sample using 16-point scales for flavor and texture attributes. Warner-Bratzler shear force (WBSF) were determined. The trained panel results and WBSF values were analyzed using Proc Means and Proc GLMMIX procedures of SAS (version 9.4, SAS Institute, Cary, NC) with a predetermined α of 5%.ResultsQuality grade impacted flavor for the inside round (P &lt; 0.05). USDA quality grade had minimal effect on tenderness as expected, as beef round cuts are highly active muscles in the animal and contain considerable amounts of connective tissue. Cooking method and internal cook temperature endpoint, or cooking time for the stewing cooking treatment, impacted beef flavor to a greater extent (P &lt; 0.05). When pan fried, thicker cuts resulted in more positive flavor attributes. For cuts that were roasted, cooking to higher internal temperatures resulted in higher levels of beef identity, roasted, and umami flavors and less serumy/bloody flavors, as well as decreased tenderness (P &lt; 0.0001), especially in inside round roasts. Marinated round cuts were more tender than their non-marinated counterparts (P &lt; 0.0001). Cuts that were thinner and had longer cooking times were more tender but had more off-flavor attributes (P &lt; 0.05).ConclusionCut thickness, cooking method, length of cooking or internal cook temperature endpoint, and presence of marinade affected flavor and texture of bottom round, eye of round, and inside round cuts. This data will be useful in providing consumer and food service personnel recommendation on how to maximize the flavor and texture of beef round cuts.

Comparison of Six Commercial Meat Starter Cultures for the Fermentation of Yellow Mealworm (Tenebrio molitor) Paste.

In this study, six commercial meat starters, each consisting of a pure strain of a lactic acid-fermenting bacterium (including Lactococcus lactis, Lactobacillus curvatus, L. farciminis, L. plantarum, L. sakei, and Pediococcus acidilactici), were tested for their ability to ferment a paste produced from the yellow mealworm (Tenebrio molitor). During fermentation, microbial counts, pH, and the bacterial community composition were determined. In addition, UPLC-MS was applied to monitor the consumption of glucose and the production of glutamic (Glu) and aspartic (Asp) acid. All tested starters were able to ferment the mealworm paste, judged by a pH reduction from 6.68 to 4.60–4.95 within 72 h. Illumina amplicon sequencing showed that all starters were able to colonize the substrate efficiently. Moreover, the introduction of the starter cultures led to the disappearance of Bacillus and Clostridium species, which were the dominant microorganisms in un-inoculated samples. Of the six cultures tested, Lactobacillus farciminis was most promising as its application resulted in the largest increase (±25 mg/100 g of paste) in the content of free glutamic and aspartic acid. These amino acids are responsible for the appreciated umami flavour in fermented food products and might stimulate the acceptance of insects and their consumption.

Induction of Fos expression in the rat brain after intragastric administration of dried bonito dashi

ABSTRACT Objectives: Dried bonito dashi, a traditional Japanese fish broth made from dried bonito tuna, enhances food palatability due to its specific umami flavor characteristics. However, the pattern of brain activation following dashi ingestion has not been previously investigated. Methods: We mapped activation sites of the rat brain after intragastric loads of dried bonito dashi by measuring neuronal levels of the Fos protein, a functional marker of neuronal activation. Results: Compared to intragastric saline, intragastric dashi administration produced enhanced Fos expression in four forebrain regions: the medial preoptic area, subfornical organ, habenular nucleus, and central nucleus of the amygdala. Interestingly, the medial preoptic area was found to be the only feeding-related hypothalamic area responsive to dashi administration. Moreover, dashi had no effect in the nucleus accumbens and ventral tegmental area, two connected sites known to be activated by highly palatable sugars and fats. In the hindbrain, dashi administration produced enhanced Fos expression in both visceral sensory (caudal nucleus of the solitary tract, dorsal part of the lateral parabrachial nucleus, and area postrema) and autonomic (rostral ventrolateral medulla, and caudal ventrolateral medulla) sites. Discussion: The results demonstrate the activation of discrete forebrain and hindbrain regions following intragastric loads of dried bonito dashi. Our data suggest that the gut–brain axis is the principal mediator of the postingestive effects associated with the ingestion of dashi.

Fermentation of onion (Allium cepa L.) peel by lactic acid bacteria for production of functional food

Onion (Allium cepa L.) peel is rich in flavonoids (e.g. quercetin), which have attracted interest for their beneficial health effects, including antioxidative and anti-inflammatory activities, but it is usually discarded. This study tested a potential way to utilize onion peel, by producing a functional food by fermentation with lactic acid bacteria (LAB). Of 13 Lactobacillus strains tested, five (E19, E31, J11, J41, and 361) reached viable cell counts > 108 CFU/mL. LAB fermentation did not affect the quercetin content of onion peel. Five strains inhibited the activity of angiotensin I-converting enzyme, which converts angiotensin I into angiotensin II, a potent vasoconstrictor that regulates blood pressure. We selected Lactobacillus plantarum E31 for further study, and onion peel fermented by using this strain inhibited the enzyme activity. Analysis with a taste-sensing system showed that fermentation with strain E31 produced onion peel that was more acidic and had less umami flavor and aftertaste of anionic bitterness than unfermented samples. This study proposes a new approach to utilize a food by-product by adding value via production of a new functional food—fermented onion peel—which contains both flavonoids and probiotics.

Vacuum radio frequency drying: a novel method to improve the main qualities of chicken powders.

Vacuum radio frequency drying (VRFD) combining the advantages of RF heating with vacuum drying (VD) was applied to produce chicken powders. Drying time and some properties of VRFD the powders were compared with VD and microwave vacuum drying (MVD) (915MHz and 2450MHz). Results showed that the total drying time of VRFD chicken powders was the shortest (100min) while that for VD powders was the longest (180min). VRFD chicken powders exhibited the lowest hygroscopicity (2.17%), the highest water holding capacity (254.80%), and better color and taste. Besides, VRFD powders had maximum umami flavor among the obtained powders. Contrarily, the color and flavor of VD powders were the most undesirable. Additionally, VRFD had less effect on protein secondary structures compared with MVD. It was concluded that, VRFD possesses the necessary potential for use at industrial level in the production of chicken powders with high qualities.

Fermentation of sugar kelp (Saccharina latissima)\u2014effects on sensory properties, and content of minerals and metals

Fermentation is an ancient technique for preserving food and feed, and for moderating taste and texture of foods. Fermentation of seaweeds for generating novel food products has yet only been described for few red algae. Here, sugar kelp (Saccharina latissima) was heat-treated and fermented using lactic acid bacteria (LAB). Taste, smell and texture of the fermented product was compared to fresh sugar kelp and two commercial seaweed products (nori and wakame). Tissue contents of dry matter, nitrogen, mannitol, and selected minerals and trace metals of the fresh and fermented sugar kelp were quantified and compared. In the fermentation process, the pH was reduced to 4.5 within 40 h, with LAB counts increasing 100-fold and no Bacillus cereus present. Heat-treatment and fermentation caused a reduced saltiness and umami flavour of the sugar kelp, a less slimy visual appearance and a reduced smell of sea, whereas the texture and protein content was unchanged compared to the fresh sugar kelp. The fermented sugar kelp had a stronger bite than nori and wakame, a stronger smell of sea and a more salty, irony and umami rich taste than nori, but less umami and salt taste than wakame. The fermentation process reduced the contents of sodium (− 15%), cadmium (− 35%) and mercury (− 37%) in the sugar kelp. LAB fermentation of sugar kelp showed promising for broadening the food market for seaweeds as the fermented product had a milder taste, improved visual impression and smell, and a reduced content of harmful trace metals.

Analysis of flavor change in the industrial production of fungal fermentation based mussel (Mytilus edulis) cooking liquor using a laser irradiation desorption based GC/MS method

The commonly discarded mussel cooking liquor (MCL) of Mytilus edulis is an important resource for industrial preparation of fungus (Aspergillus oryzae) fermented condiment. In this study, the fermentation degree of MCL was evaluated by analyzing the changes of volatile flavor using a newly established laser irradiation desorption (LID) method coupling a 450 nm blue semiconductor laser to a headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME GC/MS). Under the optimized laser conditions (laser power 10 W, irradiation time 5 min, sample volume 3 g), the effect of fungal fermentation was investigated, and a total of 52 volatile compounds in the fermented MCL were detected, such as furans, aromatic compounds, and sulphur and nitrogen containing compounds. By strictly analyzing the characteristic volatiles, the MCL was well processed and the fermentation product showed a desirable and umami flavor, whereas the fishy and burnt smell was roughly removed. Compared with traditional analytical methods, the proposed LID–HS–SPME analysis showed significant characteristic profile and reduced time to only 5 min. The results indicated that the LID–HS–SPME analysis is reliable, efficient, and suitable for industrially used for monitoring the preparation of fungal fermented MCL.

Application of quick tempe technology for production of overripe tempe

Recent studies indicated overripe tempe potencies as source of umami flavor. However, further development of overripe tempe as food ingredient was hindered by its long production time compared to tempe and its unavailability in commercial market. In this study, quick tempe technology that replace natural lactic acid fermentation with Glucono Delta Lactone (GDL)-chemical acidification, was applied to shorten the production time of overripe tempe. In this study, three variations of GDL-chemical acidification were applied, whether it is applied in the first soaking (Tempe GDL I), second soaking (Tempe GDL II), or both soaking stages (Tempe GDL III). Visual documentations were done every 12 hours to observe mycelium growth rate and the fermentation time required to produce overripe tempe. Each variation show different mycelium growth rate. Tempe GDL I became overripe tempe after 72 hours starter inoculation, while GDL II and GDL III started to become overripe tempe after 96 hours of starter inoculation. The result suggest different method of GDL-chemical acidification for different target of production, whether it is targeting the production of fresh tempe, overripe tempe, or tempe that will be further processed as ingredient.

Ripening of Hard Cheese Produced from Milk Concentrated by Reverse Osmosis.

The application of reverse osmosis (RO) for preconcentration of milk (RO-milk) on farms can decrease the overall transportation costs of milk, increase the capacity of cheese production, and may be highly attractive from the cheese manufacturer’s viewpoint. In this study, an attempt was made to produce a hard cheese from RO-milk with a concentration factor of 1.9 (RO-cheese). Proteolysis, volatile profiles, and sensory properties were evaluated throughout six months of RO-cheese ripening. Moderate primary proteolysis took place during RO-cheese ripening: about 70% of αs1-casein and 45% of β-casein were hydrolyzed by the end of cheese maturation. The total content of free amino acids (FAA) increased from 4.3 to 149.9 mmol kg−1, with Lys, Pro, Glu, Leu, and γ-aminobutyric acid dominating in ripened cheese. In total, 42 volatile compounds were identified at different stages of maturation of RO-cheese; these compounds have previously been found in traditional Gouda-type and hard-type cheeses of prolonged maturation. Fresh RO-cheese was characterized by a milky and buttery flavor, whereas sweetness, saltiness, and umami flavor increased during ripening. Current results prove the feasibility of RO-milk for the production of hard cheese with acceptable sensory characteristics and may encourage further research and implementation of RO technology in cheese manufacture.

Sensory and physical quality assessment of Sie reuboh (Cooked Meat-an Acehnese traditional cuisine)

Sie reuboh is an Acehnese traditional cuisine which uses red-meat as the main protein and is prepared specifically with addition of beef tallow, traditional vinegar and blend of spices. The dish was extremely popular, has a long shelf life, exquisite and complex taste. However due to the changing in life styles and modernization, nowadays the dish hardly prepared at home and has varied of recipes. Based on previous studies, the updated recipe was formulated by varying the amount of beef tallow and vinegar as independent variables. Furthermore, this study aims to assess the physical quality (pH and cooking weight loss) and sensory attributes (color, aroma, flavor, texture). The sensory attributes were divided onto ten specific attributes, which were assessed with Qualitative Descriptive Analysis (QDA) method. The analysis of variance (ANOVA) showed that addition of beef tallow significantly affected (P≤0.01) the umami flavor of sie reuboh, whereas addition of vinegar significantly (P≤0.01) affected pH, cooking weight loss, color, meat flavor, sour flavor, tenderness and chewiness of produced sie reuboh descriptively. The sensory profiles of each treatment were also described, where the increasing amount of vinegar tend to decrease pH, prevent cooking weight loss and elevate color, tenderness and sour flavor of the product.1