scholarly journals New application of microbial l-glutaminase as a flavor enhancing agent in beef burgers

2022 ◽  
Vol 6 (4) ◽  
pp. 375-380
Author(s):  
R. M. Mohamed ◽  
W. A. Bazaraa ◽  
A. M. Alian ◽  
N. M. EL-Shimi

L‑glutaminase (L‑glutamine amidohydrolase EC3.5.1.2) is the key enzyme in enhancing the taste and aroma of oriental fermented foods by increasing their glutamic acid content and as a result imparting a palatable taste. Beef burgers were prepared using different levels of the partially purified L- glutaminase (2.0 to10.0 U/100 g) prepared from Aspergillus oryzae NRRL 32567. Beef burgers treated with 6.0 U/100g and the others treated with monosodium glutamate (5000 ppm) were chemically, sensory and microbiologically evaluated and compared to untreated control during frozen storage at –18 ºC for 3 months. Treatment with L‑glutaminase (6 U/100g) resulted in an increase of 443% in glutamic acid and a reduction of 63% in glutamine contents resulting in an enhanced preferable taste and odor of the prepared beef burgers. Burgers treated with 6.0 U/100g exhibited the best odor, texture, taste and overall quality scores when compared to the untreated control and samples treated with monosodium glutamate (5000 ppm). During the frozen storage of all samples, an expected slight, but significant (p≤0.05), increase in the total mesophilic bacterial count was evident and such increase was quite acceptable since numbers did not exceed the limit of 5.7x103 cfu/g. Similarly, the total psychrotrophs did not exceed 3.7x102 cfu/g.

1983 ◽  
Vol 66 (6) ◽  
pp. 1528-1531 ◽  
Author(s):  
Hiroshi Nakanishi

Abstract A gas chromatographic procedure is described for determining monosodium glutamate (MSG) in several types of food. A sample is extracted with acetone- water (1 + 1). Acetone is evaporated and an aliquot of the extract is buffered with 1M NH4OH-1M NH4CI pH 9 solution, and chromatographed directly on a column of QAE Sephadex A-25 that has been pretreated with the same buffer. MSG is eluted with 0.1N HC1, and a portion of the eluate is evaporated to dryness and reacted with dimethylformamide( DMF)-dimethylacetal to form the glutamic acid derivative, which is injected into a gas chromatograph and measured by flame ionization detection. Recoveries of MSG from sample fortified at 5-500 mg ranged from 92.8 to 100%.


2020 ◽  
Vol 9 (1) ◽  
pp. 33
Author(s):  
Jirapat Kanklai ◽  
Tasneem Chemama Somwong ◽  
Patthanasak Rungsirivanich ◽  
Narumol Thongwai

Gamma-aminobutyric acid (GABA), the inhibitory neurotransmitter, can be naturally synthesized by a group of lactic acid bacteria (LAB) which is commonly found in rich carbohydrate materials such as fruits and fermented foods. Thirty-six isolates of GABA-producing LAB were obtained from Thai fermented foods. Among these, Levilactobacillus brevis F064A isolated from Thai fermented sausage displayed high GABA content, 2.85 ± 0.10 mg/mL and could tolerate acidic pH and bile salts indicating a promising probiotic. Mulberry (Morus sp.) is widely grown in Thailand. Many mulberry fruits are left to deteriorate during the high season. To increase its value, mulberry juice was prepared and added to monosodium glutamate (MSG), 2% (w/v) prior to inoculation with 5% (v/v) of L. brevis F064A and incubated at 37 °C for 48 h to obtain the GABA-fermented mulberry juice (GABA-FMJ). The GABA-FMJ obtained had 3.31 ± 0.06 mg/mL of GABA content, 5.58 ± 0.52 mg gallic acid equivalent/mL of antioxidant activity, 234.68 ± 15.53 mg cyanidin-3-glucoside/mL of anthocyanin, an ability to inhibit growth of Bacillus cereus TISTR 687, Salmonella Typhi DMST 22842 and Shigella dysenteriae DMST 1511, and 10.54 ± 0.5 log10 colony-forming units (CFU)/mL of viable L. brevis F064A cell count. This GABA-FMJ was considered as a potential naturally functional food for human of all ages.


2018 ◽  
Vol 73 (Suppl. 5) ◽  
pp. 21-28 ◽  
Author(s):  
David R. Tennant

Background: Intakes of glutamate can be derived from its natural occurrence as a constituent of proteins, from the presence of free glutamate in certain fermented foods, and from the addition of glutamic acid and glutamates to foods as flavor-enhancing additives. Summary: Intakes of glutamate following hydrolysis of dietary proteins can be as high as 440 mg/kg bw/day for toddlers and small children. High-level intakes of glutamate from its natural occurrence  in foods or from the use of food additives, given very conservative assumptions about conditions of use, are ­similar at around 80 mg/kg bw/day for toddlers and small children. Key Messages: The use of glutamic acid and glutamates as food additives makes a marginal contribution to total intakes of glutamate from all sources.


1970 ◽  
Vol 25 (2) ◽  
pp. 105-109
Author(s):  
Manik Hossain ◽  
M Kamruzzaman Munshi ◽  
Rasheda Yasmin Shilpi ◽  
Harun Or-Rashid

An investigation was undertaken for the isolation and identification of fish-borne microorganisms from mackerel fish (Scomberomorus guttatus) collected from Savar Bazar. Radiation, low temperature (-20°C) and combination treatments were then applied for the decontamination of associated organisms. The ranges of total viable bacterial count, total coliform count, total faecal coliform count and total staphylococcal count varied from 6.5 x 104 to 1.04 x 105, 2 x 102 to 4.0 x 102, 0 to 1 x 102 and 4.4 x 104 to 3.8 x 104 cfu/g respectively, while the total fungal count was nil. Sixty-four bacterial isolates were identified including Staphylococcus (19%), Micrococcus (11%), Enterobacter (8%), Klebsiella (17%), Bacillus (19%), Escherichia (17%) and Pseudomonas (9%). To disinfect the microorganisms, the samples were irradiated at different doses (0-10.0 kGy) of gamma irradiation. Total coliform and total faecal coliform bacteria were inactivated below the detectable level at 2.5 kGy of irradiation. The number of total viable bacteria decreased by three logs when irradiated at 5.0 kGy and the number of Staphylococcus bacteria were eliminated completely after the irradiation dose of 5.0 kGy. During frozen storage, the total viable bacterial counts were gradually declined in all the samples. After six months of storage the bacterial counts were decreased about one log in all of the samples. It has been observed that combination treatments (irradiation and freezing) are more effective than the single treatment for eliminating the fish-borne bacteria. Keywords: Mackerel fish; Microbial contamination; Irradiation; Low temperatureDOI: http://dx.doi.org/10.3329/bjm.v25i2.4871 Bangladesh J Microbiol, Volume 25, Number 2, December 2008, pp 105-109


2012 ◽  
Vol 13 (5) ◽  
pp. 5482-5497 ◽  
Author(s):  
Mohsen Zareian ◽  
Afshin Ebrahimpour ◽  
Fatimah Abu Bakar ◽  
Abdul Karim Sabo Mohamed ◽  
Bita Forghani ◽  
...  

Author(s):  
Ida Bagus Agung Yogeswara ◽  
Suwapat Kittibunchakul ◽  
Endang Sutriswati Rahayu ◽  
Konrad J. Domig ◽  
Dietmar Haltrich ◽  
...  

In the present study, we isolated and screened thirty strains of GABA-producing lactic acid bacteria (LAB) from Indonesian traditional fermented foods. Two strains were able to convert monosodium glutamate (MSG) to GABA after 24 h of cultivation at 37oC based on thin layer chromatography (TLC) screening. 16S rDNA sequencing and proteomic identification using MALDI-TOF MS identified these two strains as Lactobacillus plantarum designated as L. plantarum FNCC 260 and L. plantarum FNCC 343. The highest yield of GABA production obtained from the fermentation of L. plantarum FNCC 260 was 809.2 mg/l of culture medium after 60 h of cultivation. Supplementation of 0.6 mM pyridoxal 5’-phosphate (PLP) and 0.1 mM pyridoxine led to the increase in GABA production to 945.3 mg/l and 969.5 mg/l, respectively. The highest GABA production of 1226.5 mg/l of culture medium was obtained with 100 mM initial concentration of MSG added in the cultivation medium. The open reading frame (ORF) of 1410 bp of the gadB gene from L. plantarum FNCC 260 encodes 469 amino acids with a calculated molecular mass of 53.57 kDa. The production of GABA via enzymatic conversion of monosodium glutamate (MSG) using purified recombinant glutamate decarboxylase (GAD) from L. plantarum FNCC 260 expressed in Escherichia coli was found to be more efficient (5-fold higher within 6 h) than the production obtained from fermentation. L. plantarum FNCC 260 could be of interest for the synthesis of GABA.


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