Characterisation of black cumin,pomegranate and flaxseed meals as sources of phenolic acids

The article focuses on the extraction of ten phenolic acids from black cumin (Nigella sativa L.), pomegranate (Punica granatum L.) and flax (Linum usitatissimum L.) seed meals. The extracts have been fractionated as free, esterified and insoluble‐bound phenolic compounds and quantitatively determined by HPLC–PDA. The analysed meals can be utilised for obtaining valuable phenolic acids. However, the distribution of phenolic compounds varies depending on the meal source. The insoluble‐bound fraction has been the richest for the black cumin meal, both qualitatively and quantitatively, containing all ten analysed phenolics. In the pomegranate meal, the main phenolic has been gallic acid, accounting for nearly 48% in free form. The esterified form of the flaxseed meal has been abundant with ferulic (1025.44 ± 3.99 mg kg^?1 dry weight), caffeic and p‐coumaric acids. The total amount of phenolic acids would be underestimated if only free fractions would be taken into account, while neglecting esterified (for the pomegranate and flax meals) and insoluble‐bound fractions (for the black cumin and pomegranate meals).     

Enrichment of ω‐3 fatty acids in flax seed oil by alkaline lipase of Aspergillus fumigatus MTCC 9657

Flax seed oil obtained from the seeds of flax plant (Linum usitatissimum, L.) is an unexploited source which contains ω‐3 and ω‐6 fatty acids. Flax seed oil is hydrolysed with a novel alkaline lipase from Aspergillus fumigatus MTCC 9657 for the removal of unwanted fatty acids and enrichment of ω‐3 fatty acids. An appropriate balance of ω‐3 and ω‐6 polyunsaturated fatty acids and enzymatic enrichment of polyunsaturated fatty acids in diet promote nutrition and health. Fatty acid composition shows that flax seed oil contains about 26.80%, 13.5% and 25.45% of ω‐3 and ω‐6 fatty acids in triglyceride (TG), diglyceride (DG) and monoglyceride (MG), respectively. After 8 h of hydrolysis, ω‐3 content was increased to 39% in TG, showing that unwanted saturated fatty acids are removed. ω‐6 content of triglycerides in flax seed oil also showed 54.76% increase after 8 h of hydrolysis. An enzymatic method of hydrolysis by fungal lipase was developed by this study and achieved to concentrate the essential fatty acids linoleic acid (LA) and α‐linoleic acids (ALA).     

Physical properties,chemical characterization and fatty acid composition of Mexican chia (Salvia hispanica L.) seeds

Chia seeds were utilized by Aztecs as food and for medicinal purposes. Nowadays, this crop is gaining importance in many countries, due to its nutritional attributes. Some physical properties and chemical characteristics of chia seeds from four different regions of Mexico were evaluated and compared. Seed size distribution was not significantly affected (P > 0.05) by the region, with similar values of seed length (2.03–2.10 mm), width (1.27–1.32 mm), thickness (0.77–0.81 mm) and surface area (4.95–5.42 mm²). Bulk density (662–741 kg m^?3), geometry and granulometric distribution were also determined. Origin of tested seeds significantly (P < 0.05) influenced their composition; all seeds had high contents of protein (18.5–22.3%), fat (21.5–32.7%) and fibre (20.1–36.1%). Chia seeds ratio between omega‐3 and omega‐6 fatty acids was 3:1 for the studied regions; seeds from Chiapas and Michoacán had the highest proportion of ω‐6 and ω‐3 fatty acids. The studied seeds contained phenolic compounds in the range of 0.53–0.71 mg GAE g^?1.     

Partial purification of a polygalacturonase from a new Aspergillus sojae mutant and its application in grape mash maceration

The use of polygalacturonase (PG) preparations in winemaking promotes the release of phenolic compounds. A PG from a new source, Aspergillus sojae mutant, was semi‐purified and tested for grape mash maceration. Crude extract (CE), a commercial pectinase, and two high PG activity semi‐purified preparations, F_I and F_II, were applied for maceration at PG activity of 3.5 U g^?1 of grape for 46 h. Enzyme‐assisted maceration significantly (P < 0.05) increased the total phenolic content from 255.8 to 916.3 ± 5.2, 5732.9 ± 9.9, 563.4 ± 6.7 and 620.6 ± 18.4 mg L^?1 for CE, commercial pectinase, F_I and F_II, respectively. The content of individual phenolics such as gallic, protocatechuic, chlorogenic and p‐coumaric acids was improved. Principal component and hierarchical clustering analyses suggested that CE has a better performance upon the release of phenols. Semi‐purified preparations acted similar to commercial pectinase. These findings open an opportunity for the potential use of PG from the mutant strain as an alternative macerating enzyme.     

Phenolic profile of blackberry wine produced using Korean winemaking techniques in earthenware jars

This research evaluated the winemaking potential of ‘Natchez’ and ‘Triple Crown’ blackberries grown in Oklahoma and examined the phenolic composition of blackberry wines made using modified Korean traditional winemaking techniques. The winemaking variables were fermentation temperature (21.6 vs 26.6°C), and fermentation type (yeast inoculation vs wild fermentation). High‐performance liquid chromatography was used to examine the phenolic compounds in blackberry juice and wine. The phenolic compounds consisted of anthocyanins (kuromanin, keracyanidin, delphinidin) and phenolic acids (gallic acid, catechin, caffeic acid, epicatechin, p‐coumaric acid). The ‘Natchez’ berries had higher concentrations of anthocyanins (kuromanin) while ‘Triple Crown’ berries had higher levels of phenolic acids (p‐coumaric acid). For many compounds, a higher fermentation temperature generally corresponded to higher concentrations of the phenolic compound in the wine after three months aging, but this was not universally observed. Accordingly, fermentation temperature may best be matched with individual cultivars via experimentation in order to maximise extraction and retention of phenolic compounds in the finished wines. Overall, the Korean traditional winemaking technique may be a good technique to add value to wines made from blackberries suited for production in a mid‐continental climate such as the central USA. © 2018 The Institute of Brewing & Distilling     

Impact of different preservation treatments on lipids of the smooth clam Callista chione

The soft clam Callista chione is highly appreciated among marine inhabitants for nutritional, commercial and economic reasons. This work aims to determine the lipid classes’ profile of C. chione and the effect of different preservation treatments on them. C. chione meat was found to be a rich source of dietary phospholipids (PhLs), ω‐3 fatty acids and carotenoids, encouraging the exploitation of the species as human food. Among treatments, only marinating reduced the PhLs content. Parboiling and freezing resulted in a significant decrease in unsaturated fatty acids, while marinating caused partial replacement of polyunsaturated with monounsaturated fatty acids. Lipid quality indices remained favourable for a healthy diet. With the exception of astaxanthin, the rest of the carotenoids identified were susceptible to processing and frozen storage. Parboiling and freezing of the vacuum‐packed meats for up to 4 months would be most appropriate, among the treatments applied, for preserving the lipid quality of C. chione.     

Phenolic compounds in peanut seeds: Enhanced elicitation by chitosan and effects on growth and aflatoxin B1 production by Aspergillus flavus

Effects of chitosan and Aspergillus flavus to enhance elicitation of phenolic compounds in viable peanut seeds were conducted at two water activity levels. In vitro effects of phenolic acids on A. flavus growth and aflatoxin B₁ production were also studied. Chitosan enhanced elicitation of free phenolic compounds (FPC) at Aw .85 and .95 levels. A. flavus initially decreased and subsequently increased FPC content, but bound phenolic compounds (BPC) decreased during incubation. Chitosan + A. flavus treatment caused an increase in FPC reaching a plateau between 24–48 h at Aw .85 while BPC levels increased over the same period at both Aw levels. Major free and bound phenolic acids detected were p‐coumaric, ferulic and an unknown phenolic acid eluting at a retention time of 22 min. Generally, chitosan significantly enhanced elicitation of free ferulic and p‐coumaric acids and bound p‐coumaric acid at Aw .95. Free unknown phenolic and bound ferulic acids at Aw .85 were enhanced by chitosan. A. flavus caused significant induction of bound p‐coumaric and ferulic acids and free unknown phenol at Aw .85. Chitosan + A. flavus enhanced free p‐coumaric (3 h) and unknown phenolic acids and bound p‐coumaric acid at Aw .95 while bound ferulic acid was enhanced at Aw .85. Chitosan limited A. flavus growth and subsequent aflatoxin production by inducing susceptible tissues to produce more preformed phenolic compounds.

Analysis of liquid cultures of A. flavus revealed that p‐coumaric, ferulic, and vanillic acids and a mixture of these phenolic acids slightly inhibited mycelial growth. Production of aflatoxin B₁ by A. flavus was completely inhibited at 1 mM and 10 mM concentrations of the phenolic acids and their mixture on four days of incubation. Mode of action of phenolic acids is likely on the secondary pathway for aflatoxin B₁ production and not on the primary metabolism for fungal growth.     

Release of phenolic acids from defatted rice bran by subcritical water treatment

BACKGROUND: Oil production from rice bran, an undervalued by‐product of rice milling, produces defatted rice bran (DRB) as a waste material. Although it is considered a less valuable product, DRB still contains useful substances such as phenolic compounds with antioxidant, UV‐B‐protecting and anti‐tumour activities. In this study the phenolic acids in DRB were extracted with subcritical water at temperatures of 125, 150, 175 and 200 °C. RESULTS: Analysis of total phenolics using Folin–Ciocalteu reagent showed about 2–20 g gallic acid equivalent kg^?1 bran in the extracts. High‐performance liquid chromatography analysis showed low contents of phenolic acids (about 0.4–2 g kg^?1 bran). Ferulic, p‐coumaric, gallic and caffeic acids were the major phenolic acids identified in the extracts. Thermal analysis of the phenolic acids was also done. The thermogravimetric curves showed that p‐coumaric, caffeic and ferulic acids started to decompose at about 170 °C, while gallic acid did not start to decompose until about 200 °C. CONCLUSION: Subcritical water can be used to hydrolyse rice bran and release phenolic compounds, but the high temperatures used in the extraction can also cause the decomposition of phenolic acids. Copyright © 2010 Society of Chemical Industry     

Antioxidant Activity of Pea (Pisum sativum L.) Seed Coat Acetone Extract

The contents of phenolic compounds in seed coat of pea and their antioxidative properties were examined. The pea seed coat was extracted with acetone-water (7:3 v/v) mixture and the extract was separated into five (?V) fractions using a Sephadex LH-20 column chromatography. Antioxidative activity of extract and fractions was measured by the oxidation of phosphatidylcholine to hydroxyperoxidephosphatidylcholine in liposome model and by scavenging effects of superoxide radical anion in xanthine-xanthine oxidase system. Phenolic compounds of extract and fractions were determined by spectrophotometric methods and characterized by HPLC analysis. Strong antioxidative properties were noted for extract and its five fractions measured by liposome method. The extract and fractions I, IV and V also showed scavenging effects of superoxide radical anion. A statistically significant correlation (P≤0.05) was found between the inhibition of PC oxidation in the system tested and contents of either total phenols or tannins. However no statistically significant correlation was found between O^•−₂ scavenging effect and contents of either total phenols or tannins. The HPLC analysis of phenolic compounds of extract and active fractions showed the presence of some phenolic acids (benzoic and cinnamic acids, and cinnamic acid derivatives), flavone and flavonol glycoside.     

Green method for determination of phenolic compounds in mung bean (Vigna radiata L.) based on near‐infrared spectroscopy and chemometrics

Mung bean grains exhibit high level of antioxidant activity due the presence of phenolic compounds. Near‐infrared spectroscopy (NIRS), in conjunction with chemometrics, was used to develop a rapid, nondestructive, chemical free and easy‐to‐use method to determine these compounds in sixty genotypes of mung bean. NIRS calibration curve with high‐performance liquid chromatography (HPLC) as reference method was used to determine phenolic compounds (catechin, chlorogenic acid, caffeic acid, p‐coumaric acid, t‐ferulic acid, vitexin, isovitexin, myricetin, quercetin and kaempferol). It was observed that partial least square regression (PLSR) model in the wavelength range of 1600–2500 nm with standard normal variate (SNV) and linear baseline correction (LBC) as preprocessing techniques can measure phenolic compound accurately (R² > 0.987) with root‐mean‐square error less than 1.82%. This study shows that NIRS along with chemometrics is an accurate method to estimate the phenolic compounds rapidly and nondestructively.     

Effect of defatting and decortication on distribution of fatty acids,phenolic and antioxidant compounds in sorghum (Sorghum bicolor) bran fractions

Sorghum bran components could be a potential source of nutrients and phytochemicals for industrial applications. The effect of defatting with hexane and different degrees of decortication on distribution of fatty acids, phenolic compounds, colour (L, a and b) and antioxidant activity (DPPH) of red (RS) and white (WS) sorghums was studied. The decortication process was carried out at time intervals of 1–6 min. Defatted and nondefatted fractions were analysed. The content of polyunsaturated fatty acids (PUFA) was higher than monounsaturated fatty acids (MUFA); the content of MUFA was higher than saturated fatty acids (SFA). Linoleic, oleic and palmitic acids predominated in all fractions. Significant differences in the content of palmitic and linolenic acids between sorghums were found. RS had higher content of palmitic, and WS was higher in linoleic acid. Defatted samples contained lower amounts of phenolic compounds and higher antioxidant activities, than nondefatted samples. RS was a better source of total phenolic compounds and antioxidant activity compared with WS, but WS presented a more suitable profile of fatty acids. In conclusion, fractions of both types of sorghums can be used in cereal‐based products to enhance their phytochemical profile.     

CAPILLARY GAS CHROMATOGRAPHY ANALYSIS OF LIPID COMPOSITION AND EVALUATION OF PHENOLIC COMPOUNDS BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY IN ITALIAN WALNUT (JUGLANS REGIA L.): IRRIGATION AND FERTILIZATION INFLUENCE

ABSTRACT

Rapid analytical techniques were used to analyze the lipid fraction and to characterize phenolic compounds in Italian walnuts (Chandler cv.) grown in the same experimental orchard under different agronomical conditions. Lipid components such as fatty acids, sterols and tocopherols were determined by capillary gas chromatography using a flame ionization detector. Linoleic and linolenic acids were the most representative ω‐6 and ω‐3 essential dietary fatty acids present. A total lipid chromatogram was used to simultaneously determine free sterols and tocopherols. Walnuts contained substantial amounts of γ‐ and δ‐tocopherol, which explains their antioxidant properties. Sitosterol, Δ⁵‐avenasterol and campesterol were the major free sterols found. Micellar electrokinetic chromatography was used to analyze simple and complex phenols (tannin profile), while the total phenol amount and the antioxidant activity of phenolic extracts were assessed by spectrophotometric assays with Folin‐Ciocalteu and ABTS^•+ reagents, respectively. The total phenol content was higher than most foodstuffs. Moreover, more than 96% of the phenolic fraction belonged to the tannin class. Statistical analysis of the data showed that higher levels of nitrogen fertilization led to a significant increase in linoleic acid. This effect can induce a faster oxidation of lipid fraction of walnuts. Nevertheless, major nitrogen fertilization and irrigation were able to enrich walnuts in phenolic compounds.

PRACTICAL APPLICATIONS

Walnuts (Juglans regia L.) are a good source of essential fatty acids, tocopherols and phenolic compounds that contribute to reducing the risk of coronary heart disease, and also inhibit the oxidation of human plasma and low density lipoproteins. In this work, the applicability of fast analytical determinations was utilized to discriminate different walnut samples. Total lipid chromatogram was used for the simultaneous determination of the profile of sterols and tocopherols; micellar electrokinetic chromatography was used for the phenolic separation, which takes less than 10 min. The proposed methods are ideal for routine analysis of the lipidic and phenolic fractions in order to control the quality of walnuts.

     

Composition and Nutrient Value Proposition of Brewers Spent Grain

Brewer's spent grain (BSG), a major brewing industry byproduct, is generated in large quantities annually. This review summarizes research into the composition and preservation of BSG, different extraction techniques for BSG proteins and phenolic acids, and the bioactivities of these phenolic components. Moreover, this article also highlights BSG integration into foodstuff for human consumption and animal feed supplements. BSG is considered a rich source of fiber, protein, and phenolic compounds. The phenolic acids present in BSG are hydroxycinnamic acids (ferulic, p‐coumaric, and caffeic acids), which have many biofunctions, such as antioxidant, anticarcinogenic, antiatherogenic, and antiinflammatory activities. Previously, attempts have been made to integrate BSG into human food, such as ready‐to‐eat snacks, cookies and bread, to increase fiber and protein contents. The addition of BSG to animal feed leads to increased milk yields, higher fat contents in milk, and is a good source of essential amino acids. Therefore, many studies have concluded that integrating the biofunctional compounds in BSG into human food and animal feed has various health benefits.     

Phenolic compounds in peanut seeds: Enhanced elicitation by chitosan and effects on growth and aflatoxin b1 production by aspergillus flavus

Effects of chitosan and Aspergillus flavus to enhance elicitation of phenolic compounds in viable peanut seeds were conducted at two water activity levels. In vitro effects of phenolic acids on A. flavus growth and aflatoxin B₁ production were also studied. Chitosan enhanced elicitation of free phenolic compounds (FPC) at Aw .85 and .95 levels. A. flavus treatment initially decreased and subsequently increased FPC content, but bound phenolic compounds (BPC) decreased during incubation. Chitosan + A. flavus treatments caused an increase in FPC that reached a plateau between 24–48 h at Aw .85 while BPC levels increased over the same time period at both Aw levels. The major free and bound phenolic acids detected were p‐coumaric and ferulic acids and an unknown phenol that eluted at a retention time of 22 min. Generally, chitosan treatment significantly enhanced elicitation of free ferulic and p‐coumaric acids and bound p‐coumaric acid at Aw .95. Free unknown phenolic and bound ferulic acids at Aw .85 were enhanced by chitosan. A. flavus treatment caused significant induction of bound p‐coumaric and ferulic acids and free unknown phenol at Aw .85. Chitosan + A. flavus treatment measure to reduce or eliminate pre‐harvest contamination by A. flavus and aflatoxins contributes to sustainable agriculture, especially to developing countries.

The enhanced elicitation of preformed phenolic compounds by chitosan may provide seed tissues an additive or synergistic effect in controlling aflatoxin‐producing fungi and preventing aflatoxin contamination. Further, such investigation will help elucidate the biochemical basis of elicitor‐host interaction that contribute to defensive responses of host tissues. Identification of biochemical factors in induced resistance involves a refinement in the separation and identification of induced phenolic compounds. Methodologies such as spectrophotometric assay or reverse‐phase high performance liquid chromatography (HPLC) may be used to evaluate phenolic compound induction by these elicitors. In addition, these compounds can be tested on their effects on A. flavus mycelial growth and subsequent aflatoxin production in vitro.

Hence, a study on the possible role of phenols on the natural resistance of peanuts to A. flavus invasion was conducted with the following objectives: 1) to quantitate changes in free and bound phenolic compounds influenced by chitosan, A. flavus, and water activity (Aw) levels by Folin‐Ciocalteu assay; 2) to separate, identify, and quantitate free and bound phenolic acids influenced by elicitors and Aw levels; and 3) to determine the effects of phenolic acids in liquid cultures at different concentrations on mycelial growth and aflatoxin B₁ production by A. flavus.     

Riboflavin Phototransformation on the Changes of Antioxidant Capacities in Phenolic Compounds

Eight phenolic compounds including: p‐coumaric acid, vanillic acid, caffeic acid, chlorogenic acid, trolox, quercetin, curcumin, and resveratrol were treated with riboflavin (RF) photosensitization and in vitro antioxidant capacities of the mixtures were determined by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2’ azino bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Mixtures containing p‐coumaric acid and vanillic acid under RF photosensitization showed increases in ferric ion reducing ability and radical scavenging activity of DPPH, whereas mixtures of other compounds had decreases in both radical scavenging ability and ferric reducing antioxidant power. Hydroxycoumaric acid and conjugated hydroxycoumaric and coumaric acids were tentatively identified from RF photosensitized p‐coumaric acid, whereas dimmers of vanillic acid were tentatively identified from RF photosensitized vanillic acid. RF photosensitization may be a useful method to enhance antioxidant properties like ferric ion reducing abilities of some selected phenolic compounds.     

Evaluation of the bioactive compounds and the antioxidant capacity of grape pomace

Grape pomace is an agro‐industrial residue produced worldwide and mainly employed for animal feed or as a fertiliser. Several studies have shown that grape pomace is a rich source of bioactive compounds, such as phenolic compounds, polysaccharides, fatty acids and others. Three varieties of grape pomace were evaluated in this study. Antioxidant activity was determined by three different methods, namely, DPPH˙, ABTS and ferrous ion assays. Fatty acids and phenolic compounds were identified, respectively, by gas and liquid chromatography. Results showed that grape pomace is a rich source of polyunsaturated fatty acids and phenolic compounds. Cabernet Sauvignon pomace revealed higher values of total phenolic compounds, total flavonoids and total monomeric anthocyanin, and presented the lowest value of EC₅₀, and thus a higher antioxidant activity among the samples analysed.     

Phenolic acid concentrations in organically and conventionally cultivated spring and winter wheat

BACKGROUND: Organic crops are often thought to contain more phenolic secondary metabolites than conventional ones. This study evaluated the influence of organic and conventional farming on concentrations of phenolic acids in spring and winter wheat cultivars. RESULTS: Five phenolic acids were identified: ferulic, sinapic, p‐coumaric, vanillic and p‐hydroxybenzoic acid. Ferulic acid was the main phenolic acid in the grain of all tested wheat varieties. Significant differences among the examined cultivars in concentration of particular compounds were observed. Concentrations of phenolic acids varied significantly in organic and conventional wheat. Levels of ferulic and p‐coumaric acids, as well as the total phenolic acid content were higher in organic crops. Concentrations of sinapic acid in spring wheat, as well as vanillic and p‐hydroxybenzoic acid levels in both types of wheat were significantly higher in conventional grains. The 1000 kernel weight (TKW) of spring and winter wheat was significantly lower in organic crops. CONCLUSION: Organically produced spring and winter wheat had significantly higher concentrations of ferulic and p‐coumaric acid as well as the total phenolic acid content than conventional wheat, though the differences in the levels of phenolics were not large. However, these differences are probably caused mainly by smaller size of organic wheat kernels (lower TKW). Copyright © 2011 Society of Chemical Industry     

Changes in bioactive compounds and antioxidant activity during convective drying of murta (Ugni molinae T.) berries

Murta (Ugni molinae T.) berries were air‐dried at five temperatures (40, 50, 60, 70 and 80 °C), and the changes in β‐carotene, phenolic acids, total phenolic and flavonoid contents and antioxidant capacities (DPPH and ORAC) were investigated. The berries showed a high content of β‐carotene, which decreased during drying temperature between 40 °C and 80 °C. Free and bound phenolic acids were also determined, showing gallic acid to be the prevalent phenolic acid. Total phenolic and flavonoid contents in the dried berries showed a higher decrease at lower temperature due to longer drying time. The radical‐scavenging activity also showed higher antioxidant activity at higher drying temperatures (70–80 °C) than at lower drying temperatures (40–50 °C). Total phenolic content (TPC) and flavonoids showed good correlation with antioxidant capacity. Murta berries proved to be an excellent source of antioxidants and bioactive compounds and are therefore a potential ingredient for new functional food products.     

Antioxidant and tyrosinase inhibitory activity of Rosa roxburghii fruit and identification of main bioactive phytochemicals by UPLC‐Triple‐TOF/MS

The content of bioactive phytochemicals, antioxidant activity and tyrosinase inhibitory activity of the hydroalcoholic extracts of Rosa roxburghii were determined. Yellow fruits of cultivated R. roxburghii showed the highest phenolic content (154.81 mg gallic acid g^?1), and the green fruits of wild R. roxburghii showed higher content of flavonoid and triterpenoid. Rosa roxburghii fruits from different cultivars and maturity stages all demonstrated as good antioxidant agents and tyrosinase inhibitors, with IC50 value about twice of the positive standard in the DPPH assay and triple of the standard in the tyrosinase inhibitory activity assay. Nineteen compounds, mainly ellagic acids and its derivatives, flavonoids and their glycosides were identified by UPLC‐Triple‐TOF/MS analysis. As the first study of bioactive phytochemicals of R. roxburghii by UPLC‐MS, the present research may provide valuable information for fulfilling the potential of R. roxburghii in the functional food area.     

Fenton oxidation products derived from hydroxycinnamic acids increases phenolic‐based compounds and organic acid formation in sugar processing

The hydroxycinnamic acids (HCAs), caffeic acid (CaA), p‐coumaric acid (pCoA) and ferulic acid (FeA) are the main phenolic acid colour precursors present in sugar cane juice. The Fenton oxidative degradation products of these HCAs and mixture using Fe²⁺/H₂O₂ at pH 4.72 at 25 °C were identified using chromatography and mass spectrometry techniques. Oxalic (≤14 wt%), isobutyric (≤13.5 wt%) and formic acids (≤1.3 wt%) were the main organic acids formed. CaA produced the highest proportion of oxalic and isobutyric acids, while FeA produced the highest proportion of formic acid. The presence of increased proportion of oxalic acid in juice will increase the proportion of calcium oxalate scale in sugar mill heat exchangers. The phenolic‐based products identified include protocatechuic aldehyde and 4‐hydroxybenzoic acid and the basic phenols, p‐allyphenol, p‐vinylguaiacol, trans‐isoeugenol, which when present in juice may react with juice constituents to increase juice colour in subsequent processing.