Monitoring of free glutamic acid in Malaysian processed foods, dishes and condiments

Fermented shellfish condiments: A comprehensive review

Fermented shellfish condiments are globally consumed especially among Asian countries. Condiments, commonly used as flavor enhancers, have unique sensory characteristics and are associated with umami and meaty aroma. The main reactions that occur during fermentation of shellfish include proteolysis by endogenous enzymes and microbial activities to produce peptides and amino acids. The actions of proteolytic enzymes and microorganisms (predominantly bacteria) are found to be largely responsible for the formation of taste and aroma compounds. This review elaborates different aspects of shellfish fermentation including classification, process, substrates, microbiota, changes in both physicochemical and biochemical components, alterations in nutritional composition, flavor characteristics and sensory profiles, and biological activities and their undesirable impacts on health. The characteristics of traditional shellfish production such as long duration and high salt concentration not only limit nutritional value but also inhibit the formation of toxic biogenic amines. In addition, this review article also covers novel bioprocesses such as low salt fermentation and use of novel starter cultures and/or novel enzymes to accelerate fermentation and produce shellfish condiments that are of better quality and safer for consumption. Practical Application: The review paper summarized the comprehensive information on shellfish fermentation to provide alternative strategies to produce shellfish comdiments that are of better quality and safer for consumption.

Method Validation and Rapid Determination of Monosodium Glutamate in Various Food Products by HPLC-Fluorescence Detection and Method Optimization of HPLC-Evaporative Light Scattering Detection Approach without Derivatization

In this study, an effective, simple and rapid high-performance liquid chromatography (HPLC) using fluorescence (FLD) method was developed and validated for the determination of monosodium glutamate (MSG) in 57 various food samples. Besides, HPLC-Evaporate Light Scattering Detection (ELSD) method was carried out for determination of MSG without derivatization. MSG analysis was performed by derivatization with dansyl chloride at excitation 328, emission 530nm with fluorescence detector. HPLC-FLD method was carried out by using C18 (150 mm, 4.6 mm, 2.7 μm) column with the mobile phase consisting of (Water: Methanol:Glacial Acetic Acid)/(54:45:1,v/v/v). The column temperature was set at 25°C and the flow rate was set at 0.5 mL min-1 with an injection volume 20 μL. The results were linear (R2 = 0.9999) with very low quantification limits. The applied method was optimized and the validated parameters such as LOD, LOQ, accuracy, precision, linearity and robustness were calculated. The obtained results were statistically compared with each other. The validated HPLC-FLD method was successfully applied for the analysis of MSG in all of the food samples. Moreover, HPLC-ELSD method was optimized and successfully demonstrated for detect the MSG without derivatization.

Monosodium glutamate as a tool to reduce sodium in foodstuffs: Technological and safety aspects

Sodium chloride (NaCl) is the most commonly used ingredient to provide salty taste to foods. However, excess sodium in the bloodstream has been associated with the development of several chronic noncommunicable diseases. In order to limit sodium intake to levels considered safe, the World Health Organization (WHO) recommends for adults a daily intake of not more than 5 g of NaCl (less than 2 g of sodium). One of the strategic actions recommended by the Pan American Health Organization (PAHO) to reduce sodium intake is reformulation of processed foods. This recommendation indicates there is an urgent need to find salt substitutes, and umami compounds have been pointed as an alternative strategy. Like salty, umami is also a basic taste and the major compound associated to umami is monosodium L-glutamate (MSG). The available scientific data on the toxicity of MSG has been evaluated by scientific committees and regulatory agencies. The Joint FAO/WHO Expert Committee on Food Additives and the Scientific Committee on Food of the European Commission established an acceptable daily intake (ADI) not specified, which indicated that the substance offers no health risk when used as a food additive. The United States Food and Drug Administration and the Federation of American Societies for Experimental Biology classified MSG as a Generally Recognized as Safe (GRAS) substance. In this paper, an overview about salty and umami taste physiology, the potential applications of MSG use to reduce sodium content in specific industrialized foods and safety aspects of MSG as food additive are presented.

Umami taste components and their sources in Asian foods

Umami, the fifth basic taste, is the inimitable taste of Asian foods. Several traditional and locally prepared foods and condiments of Asia are rich in umami. In this part of world, umami is found in fermented animal-based products such as fermented and dried seafood, and plant-based products from beans and grains, dry and fresh mushrooms, and tea. In Southeast Asia, the most preferred seasonings containing umami are fish and seafood sauces, and also soybean sauces. In the East Asian region, soybean sauces are the main source of umami substance in the routine cooking. In Japan, the material used to obtain umami in dashi, the stock added to almost every Japanese soups and boiled dishes, is konbu or dried bonito. This review introduces foods and seasonings containing naturally high amount of umami substances of both animal and plant sources from different countries in Asia.

Monosodium glutamate in chicken and beef stock cubes using high-performance liquid chromatography

In this survey monosodium glutamate (MSG) levels in chicken and beef stock cube samples were determined. A total number of 122 stock cube samples (from brands A, B, C, D) were collected from local markets in Ankara, Turkey. High-performance liquid chromatography with diode array detection (HPLC-DAD) was used for quantitative MSG determination. Mean MSG levels (±SE) in samples of A, B, C and D brands were 14.6 ± 0.2 g kg⁻¹, 11.9 ± 0.3 g kg⁻¹, 9.7 ± 0.1 g kg⁻¹ and 7.2 ± 0.1 g kg⁻¹, respectively. Differences between mean levels of brands were significant. Also, mean levels of chicken stock cube samples were lower than in beef stock cubes. Maximum limits for MSG in stock cubes are not specified in the Turkish Food Codex (TFC). Generally the limit for MSG in foods (except some foods) is established as 10 g kg⁻¹ (individually or in combination).

Determination of Nine Food Additives in Condiment by High Performance Liquid Chromatography

The HPLC method has been developed for the determination of nine food additives (acesulfame-potassium, benzoic acid, sodium saccharin, sorbic acid, dehydroacetic acid, aspartame, methylparaben, ethylparaben, propylparaben) in condiments. Samples were precipitated , tested by the reverse-phase high performance liquid chromatography instrument with photodiode array detector . All the compounds exhibited good linear relationship with the correlation coefficient from 0.9991 to 0.9998. The recoveries were range from 87.1% to 108.5 % with the RSD values from 1.61 % to 5.13 % at the spiked levels from 5 mg/kg to 250 mg/kg. The detection limits of the method were from 0.3 mg/kg to 2.0 mg/kg. It is a convenient, accurate and effective method to determine these additives in condiment.

Sensory attributes of dishes containing shrimp paste with different concentrations of glutamate and 5'-nucleotides

The shrimp paste called belacan is a traditional umami taste condiment extensively used in Malaysia that is rich in glutamate and 5'-nucleotides. The aim of this study was to determine the concentration of glutamate and 5'-nucleotides of various types of foods prepared with belacan and to measure their sensory attributes. The concentration of free glutamic acid found in different brands of belacan was 180-530mg/100g and in local dishes 601-4207mg/100g. The total amount of 5'-nucleotides in belacan samples ranged from 0.85 to 42.25μg/g. A Quantitative Descriptive Analysis (QDA) using a list of 17 sensory attributes showed a good correlation between belacan concentration in the final food and a range of positive sensory attributes, except for bitter, sweet, sour taste and astringency. Belacan also contains bitter, sweet and sour compounds that change the positive attributes of belacan at higher concentrations. The highest aroma attributes were linked to nasi goreng belacan (belacan fried rice) while the highest flavour attributes were found in sambal belacan. There was a 32 folds significant increase of umami attributes with the addition of belacan to final foods. The optimum amount of belacan was 0.45% for asam pedas (tamarind flavoured dish with belacan), 18% for sambal belacan (chilli belacan), 1.5-2.5% for kangkong goreng belacan (stir fried water convolous with belacan), and 2% for nasi goreng belacan.

Glutamate. Its applications in food and contribution to health

This article reviews application of glutamate in food and its benefits and role as one of the common food ingredients used. Monosodium glutamate is one of the most abundant naturally occurring amino acids which frequently added as a flavor enhancer. It produced a unique taste that cannot be provided by other basic taste (saltiness, sourness, sweetness and bitterness), referred to as a fifth taste (umami). Glutamate serves some functions in the body as well, serving as an energy source for certain tissues and as a substrate for glutathione synthesis. Glutamate has the potential to enhance food intake in older individuals and dietary free glutamate evoked a visceral sensation from the stomach, intestine and portal vein. Small quantities of glutamate used in combination with a reduced amount of table salt during food preparation allow for far less salt to be used during and after cooking. Because glutamate is one of the most intensely studied food ingredients in the food supply and has been found safe, the Joint Expert Committee on Food Additives of the United Nations Food and Agriculture Organization and World Health Organization placed it in the safest category for food additives. Despite a widespread belief that glutamate can elicit asthma, migraine headache and Chinese Restaurant Syndrome (CRS), there are no consistent clinical data to support this claim. In addition, findings from the literature indicate that there is no consistent evidence to suggest that individuals may be uniquely sensitive to glutamate.