The consumption of milk-based fruit beverages enriched with plant sterols (PS) has previously showed a cholesterol-lowering effect in postmenopausal women [1]. The addition of galactooligosaccharides (GOS) to this kind of beverages could enhance their functionality, however, its effect on the colonic metabolism of PS is yet unknown. To shed light into this regard, a randomized, double blind, crossover study with postmenopausal women (n=42, 58±4 years) was carried out with the aim of evaluating GOS effect on PS colonic metabolism. Volunteers consumed daily 250 mL of a PS-enriched beverage (1%, w/v) with or without GOS (1.8%, w/v) for 6 weeks and feces samples were collected before and at the end of each intervention period. The contents of PS (sitosterol, sitostanol, campesterol, campestanol and stigmasterol) and its metabolites (ethylcoprostanol from sitosterol, methylcoprostanone from campesterol and ethylcoprostenol from stigmasterol) were measured by CG-MS [2]. Statistically significant increments (p<0.05) in sterol concentrations (mg/g freeze-dry feces) were observed after the consumption of any of the beverages (with vs. without GOS addition) expressed as median (percentile 25;75%): 8.29 (1.49;17.27) vs. 10.79 (2.14;19.30) for sitosterol, 12.95 (2.65;20.66) vs. 14.47 (4.91;21.56) for ethylcoprostanol, 2.84 (1.34;4.91) vs. 3.16 (1.27;4.80) for sitostanol, 1.09 (0.34;2.03) vs. 1.41 (0.47;2.11) for campesterol, 0.15 (0.03;0.40) vs. 0.18 (0.03;0.45) for methylcoprostanone, 0.46 (0.20;0.80) vs. 0.44 (0.23;0.82) for campestanol, and 0.07 (0.00;0.19) vs. 0.09 (0.02;0.23) for stigmasterol. No significant changes were observed in ethylcoprostenol contents after the consumption of the beverage with or without GOS (0.01 (-0.01;0.02) vs. 0.002 (-0.02;0.02)). No significant differences in net increments were observed between beverages. These results indicate that the presence of GOS in PS-enriched beverages does not modify the colonic biotransformation of PS.

[1] Alvarez-Sala et al. (2018), ‎ Food Funct., 91: 5209-5219; [2] Cuevas-Tena et al. (2019), Clin. Nutr., 38:1549-1560.

Acknowledgements: This study is part of the National Project AGL2015-68006-C2-1-R, financed by the Ministerio de Economía y Competitividad (MINECO) and the Fondo Europeo de Desarrollo Regional (FEDER). Virginia Blanco-Morales holds a research contract under the project AGL2015-68006-C2-1-R (Ref. CPI-17-025).

Major types of internal can coatings used for food and beverages are made from epoxy-based resins, which contain among their components bisphenol A (BPA) or bisphenol A diglycidyl ether (BADGE). These components can be released and reach the food. There is no specific European legislation for coatings, but there is legislation on specific substances setting migration limits. Many investigations have paid attention to BPA due to its classification as endocrine disruptor, however, studies are available concerning other analogues developed to replace it in the manufacture of these resins [1].

Ten cans of beverages were taken as study samples. The type of coating was verified using an attenuated total reflectance-FTIR spectrometer showing that most of the samples examined were coated with epoxy-phenolic resins.

The objective of the present work was to apply an analytical method based on high performance liquid chromatography with fluorescence detection (HPLC-FLD) to the simultaneous identification and quantification of fourteen compounds including bisphenol analogues (BPA, BPB, BPBP, BPC, BPE, BPF, BPG) and BADGEs (BADGE, BADGE.H₂O, BADGE.2H₂O, BADGE.HCl, BADGE.2HCl, BADGE.H₂O.HCl, cyclo-di-BADGE) in the material (cans) and in the beverage samples. For this, the cans were extracted with acetonitrile for 24 hours at 70 ºC and the extract was analyzed directly, as well as the content of the cans. This method showed an adequate linearity (R²>0.9994) and low detection levels down to 5 µg/L. In addition, a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was optimized for confirmation purposes.

This research was funded by the Ministerio de Ciencia, Innovación y Universidades, by Fondo Europeo de Desarrollo Regional (FEDER), and by Agencia Estatal de Investigación Ref. No. PGC2018-094518-B-I00 “MIGRACOATING” (MINECO/FEDER, UE).

References
[1] Lestido Cardama A. et al., Polymers 11 (2019) 2086.

It is well known that packaging materials can be a potential source of contaminants. The migration of chemicals from packaging to food and beverages is one of the main concerns for food safety authorities [1].

In the present study, a screening method was performed to investigate potential volatile migrants from polymeric can coatings of beverages. The sample was directly analyzed using a purge and trap (P&T) system. This technique allows to concentrate the volatiles in a sorbent material. A Teledyne Tekmar Stratum P&T was used and the experimental conditions were as follows: sample temperature, 90 ºC; purge flow, 40 mL/min; purge time, 20 min; desorb time, 2 min; desorb temperature, 250 ºC; and desorb flow, 400 mL/min.

The GC-MS analysis was carried out using a Finnigan Trace Gas Chromatograph Ultra with a Finnigan Trace DSQ mass detector. The volatile compounds were separated on a Rxi-624Sil MS (30m x 0.25mm x 1.40 µm) column and with an oven program from 45 to 250 ºC. The mass spectrometer was operated under electron impact ionization and data acquisition was performed in full scan (m/z range of 20-500). Compounds detected in samples were identified by using commercial mass spectral libraries.

Ten can samples were analysed for their potential volatile migrants. A wide variety of compounds including alcohols, ethers, aldehydes and some phthalates such as diethyl phthalate were identified. Only compounds with the best matches found during the library search were considered for the study.

This research was funded by the Ministerio de Ciencia, Innovación y Universidades, by Fondo Europeo de Desarrollo Regional (FEDER), and by Agencia Estatal de Investigación Ref. No. PGC2018-094518-B-I00 “MIGRACOATING” (MINECO/FEDER, UE).

References
[1] Poças, M. F. et al., Trends in Food Science & Technology 18 (2007) 219-230.

The application of medium-chain triglycerides (MCT) in food items can pave the way for its increased utilization and for consumers to avail of its benefits. Preliminary studies indicated that soymilk enrichment with MCT requires application of hydrocolloids. This study was conducted to determine the optimum levels of kappa carrageenan (K), locust bean gum (L), and glycerine (G) in MCT-enriched soymilk using response surface methodology (RSM). Addition of 30 mL MCT per 500 mL soymilk formulation was based on consumer acceptance test (n = 51). Range of input variables were 0.025-0.063% (w/v) for K and L, and 1.0-2.0% (v/v) for G. Two-factor interaction (2FI), quadratic, and linear models which predicted the overall acceptability (OA), emulsion stability (ES), and product cost (PC), respectively, were generated: OA = 6.19 – 0.10K – 0.07L – 0.17G + 0.02KL + 0.21KG – 0.33LG; ES = 9.24 + 0.32K + 0.08L – 0.01G + 0.34KL - 0.21KG + 0.61LG - 0.08K² + 0.16L² + 0.16G²; PC = 299.62 + 0.37A + 0.40B + 0.67C. A hydrocolloid combination with 0.025% K, 0.025% L, and 1.0% G was predicted and selected as the “optimal” solution (d_i = 0.903). Model validation using the optimal and two sub-optimal (0.059% and 0.062% K, 0.033% and 0.043% L, and 1.00% G) settings showed that the actual responses of both optimal (7.35 OA, 9.90 mL ES, and Php 292 PC) and sub-optimal solutions (6.80 and 5.98 OA, 10 mL ES, Php 293 PC) were within the 99% (α = 0.01) confidence and prediction intervals of the model.

Food contact materials can be made of a wide variety of materials such as plastic, metal, coatings, etc. Some examples of polymeric coatings used in food and beverages cans are epoxy resins, phenolic resins, acrylics, polyesters, etc. Used as a protective layer, they are essential to preserve the food maintaining its quality, as well as to protect it from corrosion and avoid a metallic taste [1].

Some chemicals present in these types of materials are susceptible to migrate to the food and constitute a risk for consumers’ health.

In the present work, a method based on solid-phase microextraction in headspace mode and gas chromatography coupled to mass spectrometry (HSSPME-GC-MS) was developed for the identification of potential migrants in polymeric coatings. For that purpose, a SPME holder for manual sampling and a DVB/PDMS/CAR fibre with 50–30 µm thickness was used.

Some parameters such as extraction time, equilibrium temperature or the type of fibre were optimized.

Analyses were performed on a Rxi-624Sil MS (30 m × 0.25 mm × 1.40 µm) column and under the following operating conditions: the injector temperature was set at 200ºC and the transfer line temperature was 250ºC. The ramp temperature was set from 45 to 250ºC. The mass spectrometer operated in full scan mode (20 and 500 m/z). Different compounds including, aldehydes, ethers, alkenes and alcohols among others were identified in preliminary assays. These results are in agreement with those obtained by other screening techniques.

References:

[1] Cooper I. et al. Surface Coatings International Part B: Coatings Transactions 84(2001) 91.

Acknowledgements:

This research was funded by the Ministerio de Ciencia, Innovación y Universidades, by Fondo Europeo de Desarrollo Regional (FEDER), and by Agencia Estatal de Investigación Ref. No. PGC2018-094518-B-I00 “MIGRACOATING” (MINECO/FEDER, UE).

Polymeric coatings are used in the food contact surface of metal cans to protect the food from corrosion. Migration of components from the food contact material to the food is a matter of concern from the food safety point of view, special attention has been paid to low molecular weight compounds and particularly to unknown compounds. Its identification is a current challenge in the food packaging field [1].

This study was focused on the identification of semi-volatile low molecular weight compounds present in polymeric coatings for metal food and beverage cans.

Different solvents were tried with the aim to extract compounds with different polarity present in the coating of metal cans. Samples were extracted under different conditions, both methanol and acetonitrile for 24h at 70ºC, hexane for 4h at 60ºC and a mixture of hexane: ethanol (3:1 % v/v) for 24 h at 20ºC. The chromatographic separation was performed on a Rxi-5SilMS (30 m × 0.25 mm × 0.25 µm) column. Operating conditions were as follows: injector and transfer line temperature were 300ºC. The ramp temperature was set from 40 to 300ºC. The carrier gas was helium with a flow rate of 1 ml/min and data acquisition was done in full scan mode (35 and 500 m/z). Extracts were injected in splitless mode and the injection volume was 1 µL. The preliminary assays showed that esters and alkenes were among the most abundant compounds identified.

References:

[1] EFSA Journal, 6(7):21r, 1-41.

Acknowledgements:

This research was funded by the Ministerio de Ciencia, Innovación y Universidades, by Fondo Europeo de Desarrollo Regional (FEDER), and by Agencia Estatal de Investigación Ref. No. PGC2018-094518-B-I00 “MIGRACOATING” (MINECO/FEDER, UE).

Terminalia ferdinandiana (Kakadu plum), belonging to the family Combretaceae, is endemic to Australia and has a long history of traditional medicinal applications and food cuisine by the Australian Indigenous people. This study investigated the effects of maturity stages on morphology, physicochemical parameters [total soluble solids (TSS), total acid content (TAC), pH], soluble sugar profile, and antioxidant capacity of Kakadu plum (KP) fruits that were wild harvested from different trees, and classified into four different maturity stages (immature to mature). TSS and TAC were determined by standard assays/procedures, main sugars by UHPLC–MS/MS, and antioxidant capacity [total phenolic content (TPC) and DPPH free radical scavenging capacity] by spectrophotometry. The results showed that soluble sugars (glucose, sucrose and fructose) from 1.3 to 17.7% dry weight (DW), TSS (17.0 - 52.7% DW) and TAC (1.3 - 6.7% DW) increased with maturity. However, TPC in the range of 7.4 - 21.9% DW and DPPH free radical scavenging capacity (22 - 76% inhibition at the extract concentration of 20 g.L^-1) did not follow the same trend as the one observed for soluble sugars, TSS and TAC. These differences were associated with the tree-to-tree variability as a consequence of wild harvest condition. This study has provided important information to both the KP industry and Indigenous enterprises regarding the selection of the appropriate maturity stage to harvest KP fruit to target for different markets (e.g. low sugar vs. high sugar fruit).

This study was conducted to isolate colorant-producing Aspergillus niger from the soil for its potential use to extract natural colorant for food production. A total of 14 soil samples were collected from Madhupur National Park at Madhupur Upazila under Mymensingh district. The Aspergillus niger was isolated and identified from the soil samples by following conventional mycological methods, followed by confirmatory identification by a polymerase chain reaction using specific oligonucleotide primers. For pigment production, a mass culture of A. niger was done in Sabouraud Dextrose Broth in shaking conditions for seven days. The biomass was subjected to extraction of the pigments following ethanol-based extraction methods. The extracted colorant was then concentrated using a rotary evaporator to obtain the pigments. An in vivo experiment was done with mice to assess the toxicity of the pigments. The extracted pigments were used to make cookies and lemon juice. A. niger could be isolated from three samples. The yield of pigment from A. niger was 0.75% (w/v). This is the first attempt to use A. niger isolated from soil samples for successful food production in Bangladesh. The fungal pigments can be used in the emerging fields of food and textile industries in Bangladesh.

The bioconversion of fruit by-products into new functional and clean label ingredients/additives represents a sustainable approach with great potential of application for the food sector.

The aim of this work was the exhaustive characterization of different extracts yielded from by-products of orange and lemon juice extraction (mix of peel, pomace and seeds) by the identification and quantification of the polyphenols recognized by their antioxidant properties and so their potential health benefits.

Ethanolic extracts were characterized by liquid chromatography coupled to mass spectrometry (LC-MS/MS). Separation was performed on a Kinetex® EVO C18 100 Å (150 x 3mm, 5µm) column using water and methanol acidified with 0.1% formic acid as mobile phase. Liquid chromatography with diode array detector (LC-DAD) was used for the quantification of the main polyphenols.

Orange by-product was that with a high number of polyphenols, while lemon extract was that with high concentrations. The main compounds present in orange by-product were Naringenin-7-O-rutinoside, Hesperetin-7-O-rutinoside, Isosakuranetin-7-O-rutinoside. Lemon extract was characterized by the presence of Apigenin-6,8-di-C-glucoside, Eriodyctiol-O-rutinoside, Hesperetin-7-O-rutinoside. The polyphenolic profile of the by-products was similar to those described by other authors for the respective fruit juices, but the concentration could be up to 10-fold higher according to the variety of the fruit [1, 2]. The results highlight that the origin of the extract affects its composition and therefore its chemical characterization is mandatory for food application. These fruits by-products may be a low-cost source of polyphenols that can be used as food ingredients/additives minimizing their environmental impact.

References:

[1] Khan, M. K., & Dangles, O. (2014). A comprehensive review on flavanones, the major citrus polyphenols. Journal of Food Composition and Analysis, 33(1), 85-104.

[2] Xi, W., Lu, J., Qun, J., & Jiao, B. (2017). Characterization of phenolic profile and antioxidant capacity of different fruit part from lemon (Citrus limon Burm.) cultivars. Journal of food science and technology, 54(5), 1108-1118.

Acknowledgements: This work was financially supported by the VIPACFood project (selected by ERA-NET ARIMNet2 call 2016 (Coordination of Agricultural Research In the Mediterranean) of the European Union through the 7th Framework Programme and funding by the Spanish National Institute for Agricultural and Food Research and Technology (INIA) ref. APCIN2016-00061-00-00 and by the “Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia”, Ref. No. GRC 2019/030. L. Barbosa-Pereira is grateful to the Spanish Ministry of Science, Innovation and Universities for her “Juan de la Cierva – Incorporación” Grant (Agreement No. IJCI-2017-31665).

In recent years, edible halophytes have received more attention due to their ability to tolerate a wide range of salinities. In Australia, halophytes are used in a broad range of “applications” by Indigenous Communities: in traditional cuisine, as livestock feed and for soil bioremediation. However, very limited scientific information on their nutritional profile and potential bioactivity is available. Therefore, the present study assessed the nutrient and phytochemical composition of Australian grown Seapurslane (SP) (Sesuvium portulacastrum), oldman Saltbush (SB) (Atriplex nummularia) and Seablite (SBL) (Suaeda arbusculoides) to better understand their nutritional ‘value’ and potential bioactivity. SB and SP contained more (p<0.05) fibre than commercial Australian baby spinach (same plant family) which was used as a reference (41.5 vs. 40.4 vs. 33.4 g/100 g dry weight (DW)). Furthermore, these plants can be considered as valuable sources of essential minerals (Ca, Fe, Mg and Na) and trace elements, specifically SBL had the highest contents of Ca and Fe. SB had the highest protein (20.1 g/100 g DW) and fat (2.7 g/100 g DW) content compared to other studied halophytes. The fatty acid profile consisted mainly of palmitic, stearic, oleic, linoleic and α-linolenic acids. A strong antioxidant capacity (total phenolic content and DPPH radical scavenging capacity) indicated that (poly) phenolic compounds are most likely the predominant phytochemicals in this species. These initial results are promising and suggest that Australian indigenous edible halophytes may have the potential to be utilized as functional food ingredients.