Food and feed laboratories share several similarities when facing the implementation of liquid-chromatographic analysis. Using the experience acquired over the years, through application chemistry in food and feed research, selected analytes of relevance for both areas were discussed. This review focused on the common obstacles and peculiarities that each analyte offers (during the sample treatment or the chromatographic separation) throughout the implementation of said methods. A brief description of the techniques which we considered to be more pertinent, commonly used to assay such analytes is provided, including approaches using commonly available detectors (especially in starter labs) as well as mass detection. This manuscript consists of three sections: feed analysis (as the start of the food chain); food destined for human consumption determinations (the end of the food chain); and finally, assays shared by either matrices or laboratories. Analytes discussed consist of both those considered undesirable substances, contaminants, additives, and those related to nutritional quality. Our review is comprised of the examination of polyphenols, capsaicinoids, theobromine and caffeine, cholesterol, mycotoxins, antibiotics, amino acids, triphenylmethane dyes, nitrates/nitrites, ethanol soluble carbohydrates/sugars, organic acids, carotenoids, hydro and liposoluble vitamins. All analytes are currently assayed in our laboratories.

Liquid Chromatography Analysis of Common Nutritional Components, in Feed and Food.

Among natural substances widespread in fruits, vegetables, spices, and medicinal plants, flavonoids and organic acids belong to the promising groups of bioactive compounds with strong antioxidant and anti-inflammatory properties. The aim of the present work was to evaluate the antibacterial activity of 13 common flavonoids (flavones, flavonols, flavanones) and 6 organic acids (aliphatic and aromatic acids). The minimal inhibitory concentrations (MICs) of selected plant substances were determined by the micro-dilution method using clinical strains of four species of pathogenic bacteria. All tested compounds showed antimicrobial properties, but their biological activity was moderate or relatively low. Bacterial growth was most strongly inhibited by salicylic acid (MIC = 250–500 μg/mL). These compounds were generally more active against Gram-negative bacteria: Escherichia coli and Pseudomonas aeruginosa than Gram-positive ones: Enterococcus faecalis and Staphylococcus aureus. An analysis of the antibacterial effect of flavone, chrysin, apigenin, and luteolin showed that the presence of hydroxyl groups in the phenyl rings A and B usually did not influence on the level of their activity. A significant increase in the activity of the hydroxy derivatives of flavone was observed only for S. aureus. Similarly, the presence and position of the sugar group in the flavone glycosides generally had no effect on the MIC values.

https://www.mdpi.com/2077-0383/9/1/109/pdf

Antibacterial Activity of Some Flavonoids and Organic Acids Widely Distributed in Plants.

Benzoic acid is an aromatic carboxylic acid naturally present in plant and animal tissues, which can also be produced by microorganisms. Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products. As a result of their widespread occurrence, production, and uses, these compounds are largely distributed in the environment and found in water, soil, and air. Consequently, human exposure to them can be high, common, and lengthy. This review is mainly focused on the presence and use of benzoic acid in foods but it also covers the occurrence, uses, human exposure, metabolism, toxicology, analytical methods for detection, and legal limits for benzoic acid and its derivatives. Their controversial effects and potential public health concerns are discussed.

Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses, exposure, and controversy

Goji berry fruit (Lycium spp.): antioxidant compound fingerprint and bioactivity evaluation

The blackcurrant (Ribes nigrum L., Grossulariceae), a small, perennial shrub native to central Europe and northern Asia, is cultivated throughout the world, including the United States. In addition to its anecdotal use in traditional herbal medicine, modern laboratories have demonstrated the potent anti-inflammatory, antioxidant and antimicrobial effects of blackcurrant constituents on a myriad of disease states. The properties of the blackcurrants are conferred from its biochemical constituents, some of which include anthocyans (specifically delphinidin-3-O-glucoside, delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside), flavonols, phenolic acids and polyunsaturated fatty acids. A plethora of studies have been published with regards to its various therapeutic applications. This article attempts to summarize these studies, providing a general overview of the research in this field. Several studies focus on the therapeutic potential of blackcurrants with regards to hypertension and other cardiovascular-associated illnesses, neoplastic, neurodegenerative and ocular diseases, nephrolithiasis, and diabetic neuropathy. Safety concerns and future directions are also mentioned, suggesting the critical examination of the exact mechanism of action, specific radical-scavenging capabilities of the blackcurrants and the crucial need for well-designed clinical trials to ensure the successful use of blackcurrants in a clinical setting.

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The health benefits of blackcurrants

A reversed phase HPLC method for separation and quantification of organic acids (oxalic, citric, tartaric, malic, ascorbic and lactic acids) in fruit juices was developed. The chromatographic separation was performed with a Surveyor Thermo Electron system at 10C by using potassium dihydrogen orthophosphate buffer (pH 2.8) as mobile phase, an Hypersil Gold aQ Analytical Column and diode array detection at ?=254 nm for ascorbic acid and ?=214 nm for the other organic acids. Organic acid profiles of ten species of Citrus: sweet orange, minneola, clementine, mandarin orange, pomelo, lemon, lime, sweetie, white and pink grapefruit were established. Species significantly affect the organic acid distribution of citrus fruit juices. In all citrus juices, the most abundant organic acid was citric acid, ranging from 6.88 to 73.93 g/l. Citrus juices are good sources of ascorbic acid (0.215-0.718 g/l). Average ascorbic acid was the highest in lemon juice followed by sweet orange juice, sweetie and white grapefruit.

HPLC organic acid analysis in different citrus juices under reversed phase conditions.

Fifteen apple cultivars grown in Valcea Research Station, Romania were evaluated in terms of fruit quality. Some selected compositional characteristics such as dry matter, total soluble solids, total sugar, titratable acidity, malic, citric and ascorbic acids and minerals content were investigated. Malic, citric and ascorbic acids were determined by a reversed-phase HPLC method. Sodium, calcium, magnesium, phosphorus, iron, manganese, copper, aluminium, chromium, zinc and strontium contents were determined by inductively coupled plasma-mass spectrometry following a microwave digestion while potassium content was determined by flame atomic absorption spectrometry. Large differences between cultivars were found for the contents of particular biochemical and mineral compounds. The dry matter content ranged between 12.49% (Prima) and 20.09% (Red Boskoop) while the total sugar content varied between 9.5% (Cadel) and 15.03% (Red Boskoop). The highest titratable acidity was found in Red Boskoop (0.771%), while in Starkrimson the titratable acidity was only 0.101%. The respective ranges of malic and citric acid contents of the tested samples were: 522.2-1993.7 mg/100 g and 3.5-49.1 mg/100 g. The ascorbic acid content was on average 6.18 mg/100 g. Potassium was the most accumulated nutrient in fruits. The potassium content was comprised between 82.25 mg/100 g (Mutzu) and 160.85 mg/100 g (Florina). Calcium follows, with variation limits between 1.70 mg/100 g (Starkrimson) and 8.74 mg/100g (Prima) while iron content varied between 0.19 mg/100 g (Ionagold) and 0.40 mg/100 g (Cadel and Early Red). The observed differences in composition are of such magnitude that they may affect both nutritional and sensory properties.

Compositional Characteristics of Fruits of several Apple (Malus domestica Borkh.) Cultivars

Introduction. Red and black currants are a valuable component of a healthy diet because they are an excellent source of ascorbic acid, anthocyanins and minerals. Materials and methods. Three red currant cultivars and eight black currant cultivars were evaluated in terms of fruit quality. Some selected physicochemical characteristics such as berry weight, dry matter, soluble solids, total sugars, titratable acidity and total anthocyanins were investigated. Total anthocyanin content was measured with the pH differential absorbance method while citric, malic, tartaric and ascorbic acid were quantified by a reversed-phase HPLC method. Sodium, calcium, magnesium, iron, manganese, chromium and zinc were determined by ICP- MS following a microwave digestion, while potassium content was determined by FAAS. Results. Significant differences in the physicochemical and mineral content were detected among the cultivars. The range of total anthocyanins of the tested samples was 12.14- 22.06 mg·100 g -1 (red currants) and 116.17-287.78 mg·100 g -1 (black currants). Ascorbic acid content varied between 23.23-44.62 mg·100 g -1 (red currants) and 161.58-284.46 mg·100 g -1 (black currants). Citric acid was predominant in all studied black and red currant cultivars, fol- lowed by malic and tartaric acids. Black and red currants have rich mineral composition, espe- cially potassium, calcium and magnesium. Black currant fruits were superior to red currants with regard to calcium and magnesium content. Romania/Ribesrubrum/Ribesnigrum/softfruits/redcurrants/blackcurrants / proximate composition / anthocyanins / organic acids / mineral content

/pdf/ascorbic-acid-anthocyanins-organic-acids-and-mineral-content-32o95k97lp.pdf

Ascorbic acid, anthocyanins, organic acids and mineral content of some black and red currant cultivars

The tomato processing industry generates high amounts of waste, mainly tomato skins and seeds, which create environmental problems. These residues are attractive sources of valuable bioactive components and pigments. A relatively simple recovery technology could consist of production of powders to be directly incorporated into foods. Tomato waste coming from a Romanian tomato processing unit were analyzed for the content of several bioactive compounds like ascorbic acid, β-carotene, lycopene, total phenolics, mineral and trace elements. In addition, its antioxidant capacity was assayed. Results revealed that tomato waste (skins and seeds) could be successfully utilized as functional ingredient for the formulation of antioxidant rich functional foods. Dry tomato processing waste were used to supplement wheat flour at 6 and 10 % levels (w/w flour basis) and the effects on the bread’s physicochemical, baking and sensorial characteristics were studied. The following changes were observed: increase in moisture content, titratable acidity and bread crumb elasticity, reduction in specific volume and bread crumb porosity. The addition of dry tomato waste at 6 % resulted in bread with good sensory characteristics and overall acceptability but as the amount of dry tomato waste increased to 10 %, bread was less acceptable.

/pdf/bread-enriched-in-lycopene-and-other-bioactive-compounds-by-33zdq96hg2.pdf

Bread enriched in lycopene and other bioactive compounds by addition of dry tomato waste

Ten indeterminate tomato cultivars differing in fruit shape and typology, grown simultaneously in a greenhouse from Oltenia (Southwestern Romania) and harvested at red ripe stage, were investigated for the contents in ascorbic acid, lycopene, I²-carotene, total phenolics, minerals (K, Na, Ca and Mg) and trace elements (Fe, Cu, Mn, Cr, Zn and B). In addition, their antioxidant activities were determined. Significant differences were found among tomato cultivars in all studied antioxidant compounds, as well as in the antioxidant activity. Ascorbic acid ranged from 91.9 to 329.7 mg kg-1 fw, lycopene ranged from 19.7 to 49.0 mg kg-1 fw, while total phenolic compounds varied between 300.2 and 557.8 mg kg-1 fw. Antioxidant activity ranged from 0.81 mmol Trolox kg-1 fw to 1.74 mmol Trolox kg-1 fw and it was significantly correlated to total phenolics content (r = 0.91; p< 0.05). The cocktail type cultivar â€˜Tigerâ€™ and the cherry type cultivar â€˜Belleâ€™ proved to be the most powerful in antioxidant activity and phenolic compounds while the rectangular plum shaped cultivar â€˜Portoâ€™ recorded the highest average lycopene content. A valuable cultivar proved to be the brownish red â€˜Sacherâ€™ which registered among the highest contents of phenolics, lycopene and ascorbic acid. Mineral and trace elements contents were also significantly affected by cultivars. Values recorded for K, Ca and Mg ranged from 2139.6 to 3056.9 mg kg-1, 137.7 to 325.8 mg kg-1 and 27.3 to 168.7 mg kg-1 respectively.

/pdf/antioxidant-compounds-mineral-content-and-antioxidant-2mrqriahyq.pdf

Mira Elena Ionica

Papers

HPLC organic acid analysis in different citrus juices under reversed phase conditions.

Compositional Characteristics of Fruits of several Apple (Malus domestica Borkh.) Cultivars

Ascorbic acid, anthocyanins, organic acids and mineral content of some black and red currant cultivars

Bread enriched in lycopene and other bioactive compounds by addition of dry tomato waste

Antioxidant Compounds, Mineral Content and Antioxidant Activity of Several Tomato Cultivars Grown in Southwestern Romania