Dynamics of Volatile Compounds in Triticale Bread with Sourdough: From Flour to Bread

The production of esters by specific sourdough lactic acid bacteria species is limited by the precursor concentrations

The production of fruity esters by sourdough lactic acid bacteria (LAB) and yeasts has not been explored in detail. Moreover, the biosynthesis of esters by LAB species under conditions similar to those occurring during sourdough production is still questionable. Concerning yeasts, a genome mining of 75 genomes revealed a strain dependency of the presence of seven specific ester biosynthesis genes. Accordingly, PCR assays to detect these acetate (ATF1 and ATF2) and ethyl ester (EHT1 and EEB1) biosynthesis genes were developed and used to screen 91 strains of yeast species. Concerning LAB, a genome mining of 401 genomes revealed a species dependency of the presence of three esterase-encoding genes (estA, estB, and estC). A phenotypic analysis carried out with a selection of 10 strains of the LAB species Companilactobacillus crustorum, Companilactobacillus nantensis, Companilactobacillus paralimentarius, Fructilactobacillus sanfranciscensis, Lactiplantibacillus xiangfangensis, Levilactobacillus zymae, and Limosilactobacillus fermentum in a wheat sourdough simulation medium (WSSM) supplemented with ester precursor molecules ([higher] alcohols and fatty acids) revealed that their ester biosynthesis capacity was limited by the precursor concentrations. Ethyl acetate and ethyl lactate were produced by all strains, except for those of Frul. sanfranciscensis. These results suggested that one of the esterase-encoding genes considered could be implicated in the ethyl acetate and/or ethyl lactate biosynthesis. Overall, the ester biosynthesis capacity by LAB is of great interest in view of fruity flavor formation during sourdough and sourdough bread productions.

IMPORTANCE

The present study gave insights into the production of esters, which impart fruity flavors to fermented foods, by not only sourdough yeasts but also lactic acid bacteria. It showed that some lactic acid bacteria species can synthesize the esters ethyl acetate (sweet notes) and ethyl lactate (creamy notes) under specific conditions. The information gathered during the present study will enable sourdough bakers and companies from the bakery sector to get more information on how to produce sourdoughs that can add fruity notes to the final products after a rational screening and selection of potential starter culture strains.

Fermentative profile and bacterial community structure of whole-plant triticale silage (Triticosecale Wittmack) with or without the addition of Streptococcus bovis and Lactiplantibacillus plantarum

This study aimed to investigate the effects of Streptococcus bovis and Lactiplantibacillus plantarum on the chemical composition, fermentation characteristics, bacterial communities, and predicted metabolic pathways of whole-plant triticale silage (Triticosecale Wittmack). Fresh triticale harvested at the milk stage was ensiled in sterile distilled water (CON), Streptococcus bovis (ST), Lactiplantibacillus plantarum (LP), and a combination of S. bovis and L. plantarum (LS) for 3, 7, 15, and 30 days. During ensiling, the pH and water-soluble carbohydrate (WSC) content in the inoculated groups was significantly lower than those in the CON group (P < 0.05), especially in the LS group (P < 0.05). After 7 days of ensiling, the ST and LS groups had lower (P < 0.05) starch content and higher (P < 0.05) concentrations of lactic acid (LA) and acetic acid (AA). Inoculation with S. bovis and L. plantarum, either alone or in combination, increased the abundance of Lactobacillus and Pediococcus while reducing the abundance of Weissella, Rosenbergiella, Pantoea, and Enterobacter. Metabolic prediction analysis indicated that inoculation with S. bovis enhanced starch and sucrose metabolism during the early stages of ensiling. The abundance of Streptococcus positively correlated with LA (P < 0.05) and AA concentration but negatively correlated with starch content, pH, and propionic acid (PA) concentration (P < 0.05). S. bovis inoculation increased starch hydrolysis and carbohydrate metabolism during the early stages. S. bovis and L. plantarum synergistically improved the fermentation characteristics and bacterial communities of triticale silage. Therefore, S. bovis can be used as an additive or for a fast start-up agent to improve silage fermentation quality.IMPORTANCEEnsiling is a widely used method for preserving fresh forage. Silage quality is determined by the chemical and microbial composition. Studies have shown that S. bovis grew faster than commercial species, thereby creating advantages for other lactic acid bacteria during ensiling. Therefore, we believe that S. bovis and L. plantarum can synergistically improve the fermentation characteristics and bacterial community in silage. However, few studies use high-throughput methods to explain the impact of S. bovis on silage fermentation. Results showed that S. bovis significantly affected the fermentation parameters, bacterial community, and metabolic characteristics of triticale silage. S. bovis and L. plantarum synergistically accelerated the fermentation, reducing pH and WSC while increasing lactic acid and acetic acid concentrations in the early stages of ensiling. Additionally, co-inoculation increased the abundance of Lactobacillus and Pediococcus and carbohydrate metabolism. This study emphasizes the synergistic role of S. bovis and L. plantarum in enhancing triticale silage quality, providing scientific support for novel silage additives.

Effect of Brewers' Spent Grain Addition to a Fermented Form on Dough Rheological Properties from Different Triticale Flour Cultivars

Triticale grains and brewers' spent grain (BSG) can be new sources to develop food products. From a socio-economical point of view, this fact is important since triticale is easily adapted to the climatic changes and BSG is a low-cost material which may lead to a "zero-waste" desiderate. In this study, dough rheological properties obtained from different triticale cultivars (Ingen 33, Ingen 35, Ingen 54, and Ingen 93) cultivated in the Republic of Moldova and BSG in a fermented form (BSF) in an addition level of 10% and 17.5% were analyzed. For this purpose, different rheological devices, such as Mixolab, Alveograph, HAAKE MARS 40 Rheometer, Falling Number, and Rheofermentometer, were used. Also, the pH value of the dough samples with different levels of BSF addition during fermentation was determined. According to the data obtained, BSF addition decreased water absorption values; torques values corresponding to stages 1-5 of the Mixolab curve; and dynamic rheological elastic, viscous, and complex modules. For the 17.5% BSF addition to triticale flour, the best rheological results were obtained for the Ingen 33 and Ingen 54 varieties. In addition, the BSF addition decreased the baking strength and tenacity of the Alveograph curve. The pH values of the dough samples during fermentation significantly decreased (p < 0.05) with the increased amount of BSF incorporated into the dough recipe. The highest pH decreased values were obtained for Ingen 35 with a 17.5% BSF addition, which varied between 5.58 and 5.48. During fermentation, all data recorded by the Rheofermentometer device were improved. The dough samples presented a high retention coefficient, which varied between 99.1 and 99.5%. The falling number decreased with the increasing level of BSF in triticale flour, indicating an increase in α-amylase activity in the mixed flours. The principal component analysis data showed a strong association between triticale flour varieties without a BSF addition and those with a high amount of BSF incorporated into the dough recipe. The results obtained indicate the fact that many mixes between BSF and different triticale varieties may lead to bakery products of a good quality.

Exploring the flavor changes in mung bean flour through Lactobacillus fermentation: insights from volatile compounds and non-targeted metabolomics analysis

BACKGROUND

Mung beans are highly nutritious but their leguminous flavor limits their development. Lactic acid bacteria (LAB) fermentation can decrease unwanted bean flavors in legumes and enhance their flavor. This study examined the influence of Lactobacillus fermentation on the flavor characteristics of mung bean flour (MBF) using volatile compounds and non-targeted metabolomics.

RESULTS

Lactobacillus plantarum LP90, Lactobacillus casei LC89, and Lactobacillus acidophilus LA85 eliminated 61.37%, 48.29%, and 43.73%, respectively, of the primary bean odor aldehydes from MBF. The relative odor activity value (ROAV) results showed that fermented mung bean flour (FMBF) included volatile chemicals that contributed to fruity, flowery, and milky aromas. These compounds included ethyl acetate, hexyl formate, 3-hydroxy-2-butanone, and 2,3-butanedione. The levels of amino acids with a fresh sweet flavor increased significantly by 93.89, 49.40, and 35.27% in LP90, LC89, and LA85, respectively. A total of 49 up-regulated and 13 down-regulated significantly differential metabolites were annotated, and ten metabolic pathways were screened for contributing to the flavor. The correlation between important volatile compounds and non-volatile substances relies on two primary metabolic pathways: the citric acid cycle pathway and the amino acid metabolic system.

CONCLUSION

The flavor of MBF was enhanced strongly by the process of Lactobacillus fermentation, with LP90 having the most notable impact. These results serve as a reference for identifying the flavor of FMBF. © 2024 Society of Chemical Industry.

Impact of semolina-barley mixture on the volatolomic profile of dough and pasta: characterization by a multivariate chemometric approach

BACKGROUND

Barley flour, known to be rich in various phytochemicals, has been demonstrated to improve the technological and nutritional properties of pasta; however, its volatile profile, on which its aromatic properties depend, also plays an important role in the acceptance of barley-enriched pasta. In the present work, volatile organic compounds (VOCs) of semolina doughs enriched with different percentages of barley and of the related pasta were characterized by solid phase micro-extraction (HS-SPME) coupled to gas-chromatography/mass spectrometry (GC-MS), and evaluated using a multivariate statistical approach, including principal component analysis (PCA), cluster heatmaps, Pearson's and Spearman's correlations, and partial least squares correlation (PLSC).

RESULTS

The effects of single raw materials, and their interactions, were studied to establish their importance in the volatile profile of the samples, and the correlation between the dough VOCs and the processed product VOCs was assessed. The presence of barley flour markedly affected the volatile profile in comparison with the dough obtained with only durum wheat. For alcohols, esters, terpenes, and some aldehydes there was a clear correlation with the percentage of barley. For some of the VOCs, on the other hand, a strong dependence on the ingredients interaction effect due to the mixing stage has been demonstrated.

CONCLUSION

The heatmaps allowed a good graphical visualization of the relationship between molecules and barley percentage, offering the possibility to select the best one according to the desired volatolomic footprint. Pasta with 40% of barley was demonstrated to give pasta with the most complex volatile profile. © 2024 Society of Chemical Industry.

Wholegrain triticale sourdough: Effects of triticale:Wheat flour ratio and hydration level on bread quality

Triticale (×Triticosecale) is a hybrid between wheat (Triticum spp.) and rye (Secale cereale), producing higher grain yields than wheat in challenging environments. Triticale grain is also highly nutritious. Thus, the potential of triticale grain for an expanded range of food applications should be explored. Sourdough bread has unique functional and nutritional properties, but understanding the effects of partial substitution of triticale for wheat flour and varying levels of dough moisture content on sourdough quality requires further research. The aim of this study was to evaluate the wholegrain flour of contrasting triticale cultivars in comparison to that of a common wheat cultivar in commercial sourdough breadmaking. Two triticale cultivars (Goanna and Hawkeye, selected from a panel of Australian genotypes) and one wheat cultivar (Scout) were grown in a field trial in northern NSW, Australia. Differences in quantitative texture and color parameters of the dough and sourdough bread resulting from (1) substitution of commercial wholemeal wheat flour with different proportions of wholegrain triticale or wholegrain wheat (Scout) flour (0%, 60%, 70%, 80%, and 90%) and (2) varying the amount of water included in the dough preparation (70%, 80%, 90%, and 100 g water/100 g flour) were determined. Replacement of wholemeal wheat flour with 60% wholegrain Goanna flour (protein content 12.76%; c.f. 11.50% for Hawkeye, 12.40% for Scout), and addition of 100 g water/100 g flour in the dough preparation gave the highest quality sourdough bread based on specific volume, texture, and color parameters and had similar properties to the control made from wheat alone.

Breadmaking Quality Parameters of Different Varieties of Triticale Cultivars

The aim of this research is to investigate the quality of different triticale cultivars (Ingen 35, Ingen 33, Ingen 93, Ingen 54, Ingen 40, Fanica and Costel) cultivated in the Republic of Moldova from the point of view of the flour, dough, and bread quality characteristics. This research may be of great importance for producers and consumers due to the high production capacity, wide adaptability, economic significance in human foods and nutritional value of triticale cultivars. The triticale flours were analyzed for moisture, ash, protein, wet gluten, fat, carbohydrates, acidity and color parameters (L*, a* and b* values). According to the chemical values, the triticale flours were suitable for breadmaking. The moisture content was less than 14% for all triticale varieties, indicating a long shelf life during its storage and the lowest protein content of 13.1%. The mixing, pasting and fermentation characteristics of triticale dough were analyzed using Mixolab, falling number, dynamic rheometer, alveograph and rheofermentometer devices. All triticale flours presented high levels of α-amylase, with falling number values being less than 70 s. The bread quality characteristics analyzed were the loaf volume, porosity, acidity, and sensory characteristics, and the textural parameters examined were the hardness, gumminess, chewiness, cohesiveness, and resilience. Our data showed large differences in breadmaking quality parameters. However, according to the sensory data, all the bread samples except those obtained from the Costel variety were of a very good quality, being within a total sensory range of 25.26-29.85 points. According to the relationships between flour, dough and bread characteristics obtained through principal component analysis, it may be concluded that the triticale varieties Costel, Ingen 33, Ingen 93 and Fanica, and Ingen 35 were more closely associated with each other. Significant differences were found between the triticale variety samples Ingen 40, Fanica, and Ingen 35 and between Ingen 54, Ingen 33, Costel, and Ingen 93.

Microbial ecology and metabolite dynamics of backslopped triticale sourdough productions and the impact of scale

Triticale (X Triticosecale Wittmack) is a hybrid of wheat (Triticum aestivum L.) and rye (Secale cereale L.), combining the positive attributes of both cereals. However, it has not been exploited for sourdough production yet. Further, the effect of scale on sourdough production has not been investigated systematically up to now. The aims of the present study were to assess the microbial ecology and metabolomic output of eleven spontaneously fermented, backslopped sourdough productions made with triticale flour on a scale of 100, 200, 500, and 1000 g. The acidification profile [pH and total titratable acidity (TTA)], microbial diversity (culture-dependent and culture-independent), metabolite dynamics, and appropriate correlations were determined. After ten fermentation steps, different species of Lactobacillaceae were prevalent in the mature sourdoughs, in particular Latilactobacillus curvatus, Limosilactobacillus fermentum, and Pediococcus pentosaceus. The microbial diversity could be traced back to the grains and was also present in the milling fractions (flour, bran, and shorts). Furthermore, thanks to the use of Illumina-based high-throughput sequencing and an amplicon sequence variant (ASV) approach, the presence of undesirable bacterial groups (bacilli, clostridia, and enterobacteria) during the initial steps of the backslopping cycle was revealed, as well as a finetuned taxonomic diversity of the LAB genera involved. Small sourdough productions (100 and 200 g) selected for a lower species diversity and reached a stable consortium faster than large ones (500 and 1000 g). Although a comparable final pH of 3.6-4.0 was obtained, the TTA of small sourdoughs was lower than that of large ones. Regarding the metabolic output, the simultaneous production of mannitol and erythritol, beyond ethanol and glycerol, could be linked to sourdoughs in which Liml. fermentum was the sole LAB species present. Further, the use of the arginine deiminase pathway by P. pentosaceus and Liml. fermentum was obvious. An appropriate extraction method followed by liquid injection gas chromatography coupled to triple quadrupole tandem mass spectrometry allowed the quantification of interesting volatile organic compounds, such as ethyl lactate. These findings support the inclusion of triticale as a viable alternative to wheat or rye for the production of sourdoughs that can be integrated into bread-making production schemes.

Effects of Lactic Acid Bacteria Fermentation on the Physicochemical Properties of Rice Flour and Rice Starch and on the Anti-Staling of Rice Bread

In this study, Lactococcus lactis lactis subspecies 1.2472, Streptococcus thermophilus 1.2718, and thermostable Lactobacillus rhamnosus HCUL 1.1901-1912 were used to ferment rice flour for preparing rice bread. The characteristics of fermented rice bread were studied to elucidate the mechanism by which fermentation improves the anti-staling ability of rice bread. The amylose content of rice flour increased after fermentation. The peak viscosity, attenuation value, final viscosity, recovery value, and gelatinization temperature decreased. Amylopectin was partially hydrolyzed, and the amylose content decreased. The crystallinity of starch decreased, and the minimum crystallinity of Lactococcus lactis subsp. lactis fermented rice starch (LRS) was 11.64%. The thermal characteristics of fermented rice starch, including To, Tp, Tc, and ΔH, were lower than RS (rice starch), and the △H of LRS was the lowest. Meanwhile, LRS exhibited the best anti-staling ability, and with a staling degree of 43.22%. The T22 of the LRF rice flour dough was lower, and its moisture fluidity was the weakest, indicating that moisture was more closely combined with other components. The texture characteristics of fermented rice bread were improved; among these, LRF was the best: the hardness change value was 1.421 times, the elasticity decrease was 2.35%, and the chewability change was 47.07%. There, it provides a theoretical basis for improving the shelf life of bread.

Influence of the Addition of Vital Wheat Gluten on Thermal and Rheological Properties of Triticale Flour

The aim of this study was to evaluate the effect of the addition of vital wheat gluten to triticale flour on its thermal and rheological properties. In the tested systems (TG), triticale flour from Belcanto grain was replaced with vital wheat gluten in the amounts of 1%, 2%, 3%, 4% and 5%. Wheat flour (WF) and triticale flour (TF) were also tested. For the tested flours and mixtures with gluten, the falling number, gluten content, as well as the parameters of gelatinization and retrogradation characteristics using differential scanning calorimetry (DSC) and characteristics of pasting using a viscosity analyzer (RVA) were determined. In addition, viscosity curves were plotted, and viscoelastic properties of the obtained gels were also assessed. It was observed that there were no statistically significant differences between the TF and TG samples in terms of falling number. The average value of this parameter in TG samples was 317 s. It was found that the replacement of TF with vital gluten reduced the gelatinization enthalpy and increased the retrogradation enthalpy, as well as the degree of retrogradation. The highest viscosity was characterized by the WF paste (1784 mPa·s) and the lowest by the TG5% mixture (1536 mPa·s). Replacing TF with gluten resulted in a very visible decrease in the apparent viscosity of the systems. In addition, the gels based on the tested flours and TG systems had the character of weak gels (tan δ = G″/G' > 0.1), while the values of the parameters G' and G″ decreased as the share of gluten in the systems increased.

Evaluation of Chemical and Sensory Characteristics of Sauerkraut Juice Powder and its Application in Food

Sauerkraut juice is rich in bioactive compounds; however, it is considered a byproduct of the production process. An innovative solution was found through the process of spray-drying to obtain sauerkraut juice powder. The aim of this study was to evaluate chemical and sensory characteristics of sauerkraut juice powder (SJP) and its application in foodstuffs. For SJP, total phenol content, antiradical activity, and nutritional value were determined, and the results showed that SJP is rich in minerals, especially calcium and potassium, as well as organic acids and vitamin C. SJP contains 12% NaCl and a total phenol content of 359.54 mg GAE 100 g^-1 dw. SJP has umami attributes, such as sweet, sour, and salty. Sensory tests-descriptive, rate-all-that-apply, overall liking, and volatile profile determination-were carried out separately in SJP experimental samples with olive oil and sour cream. Among the sweet, sour, and salty flavours, garlic, yogurt, and mayonnaise were also mentioned. In the detection of volatile compounds, leafy and grassy green aromas with light almond were identified in the samples with olive oil and butter and rancid cheese and fishy/amine odours were identified in samples with sour cream. There were significant differences in the overall likability of samples, but the experimental samples with SJP were more popular than control samples; therefore, SJP may be used as a salt alternative in food applications.

The study of microbial diversity and volatile compounds in Tartary buckwheat sourdoughs

Microorganisms play an essential role in forming volatile compounds in traditional staple products. Tartary buckwheat, as a medicinal and food material, has high nutritional value but its development and utilization are seriously restricted due to its poor flavor. In this study, 16S rRNA and ITS rRNA sequencing were used to analyze the microbial diversity of Tartary buckwheat sourdoughs, while HS-SPME-GC/MS was used to identify volatile compounds during fermentation. The results showed that Lactococcus and Weissella were the dominant bacterial genus. Wickerhamomyces, Penicillium, and Aspergillus were the main fungal genera in the Tartary buckwheat sourdoughs. And the main volatile compounds in Tartary buckwheat sourdough were pyrazine compounds. After 12 h of fermentation, a large amount of alcohol and esters were produced, which endowed the sourdough with a good flavor. This suggests that sourdough fermentation could significantly improve the flavor of Tartary buckwheat.

Evaluation of the variations in chemical and microbiological properties of the sourdoughs produced with selected lactic acid bacteria strains during fermentation

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Chemical, microbiological and VOCs profile showed the relevance of starter addition.

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MiSeq Illumina confirmed that Lactobacillus spp. constituted the major LAB group.

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Fructilactobacillus sanfranciscensis was the most isolated LAB species.

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Rapid acidifying LAB strains should be preferred for sourdough production.

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Number of VOCs increased in sourdoughs produced with starter culture.

This research aimed to analyze variations in chemical properties, microbiological characteristics and generated volatile organic compounds (VOCs) profile during sourdough fermentation. Sourdoughs were collected from different cities in Turkey at two different times and lactic acid bacteria (LAB) in the samples were identified with culture-independent and culture-dependent molecular methods. According to culture-dependent methodology, thirteen LAB species were identified. Lactobacillus spp. were identified as the major group according to MiSeq Illumina analysis. Technological potential of commonly isolated LAB species was evaluated. Due to high frequency of isolation, Fructilactobacillus sanfranciscensis and Lactiplantibacillus plantarum strains were better investigated for their technological traits useful in sourdough production. Experimental sourdoughs were produced with mono- and dual-culture of the selected strains and chemical properties and microbiological characteristics, as well as VOCs profile of the sourdoughs, were subjected to multivariate analysis which showed the relevance of added starter, in terms of acidification and VOCs profile.

How Different Are Industrial, Artisanal and Homemade Soft Breads?

Soft bread has a significant relevance in modern diets, and its nutritional impact on human health can be substantial. Within this product category, there is an extensive range of ingredients, formulations, and processing methods, which all contribute to the vast diversity found in the final products. This work compared the impact of three different processing methods (industrial, artisanal, and homemade preparation) on the technological (formulation and processing, as they are interconnected in real-life conditions), nutritional, and physicochemical properties of soft bread. In total, 24 types of soft bread were analyzed: 10 industrial, 6 artisanal, and 8 homemade. Although production diagrams were similar among the three methods, industrial recipes contained on average more ingredients and more additives. Industrial bread was lower in saturated fat compared to the other two groups, but contained more sugar than homemade bread. The physical properties of all loaves were comparable, with the exception of higher crumb elasticity in industrial bread compared to homemade. An analysis of volatile molecules revealed more lipid oxidation markers in industrial bread, more fermentation markers in artisanal bread, and fewer markers of Maillard reactions in homemade bread. Chemical reactions during processing seem to be the principal criterion making possible to discriminate the different processing methods. These results offer a quantitative assessment of the differences within a single product category, reflecting the real-world choices for consumers.

Comprehensive Two-Dimensional Gas Chromatography as a Powerful Strategy for the Exploration of Broas Volatile Composition

Broa is a Portuguese maize bread with characteristic sensory attributes that can only be achieved using traditional maize varieties. This study intends to disclose the volatile compounds that are mainly associated with the baking process of broas, which can be important contributors to their aroma. Twelve broas were prepared from twelve maize flours (eleven traditional maize varieties and one commercial hybrid). Their volatile compounds were analyzed by GC×GC–ToFMS (two-dimensional gas chromatography coupled with time-of-flight mass spectrometry) for an untargeted screening of the chemical compounds mainly formed during baking. It was possible to identify 128 volatiles that belonged to the main chemical families formed during this stage. Among these, only 16 had been previously detected in broas. The most abundant were furans, furanones, and pyranones, but the most relevant for the aroma of broas were ascribed to sulfur-containing compounds, in particular dimethyl trisulfide and methanethiol. Pyrazines might contribute negatively to the aroma of broas since they were present in higher amounts in the commercial broa. This work constitutes the most detailed study of the characterization of broas volatile compounds, particularly those formed during the Maillard reaction. These findings may contribute to the characterization of other maize-based foodstuffs, ultimately improving the production of foods with better sensory features.

Shedding Light on the Volatile Composition of Broa, a Traditional Portuguese Maize Bread

In Portugal, maize has been used for centuries to produce an ethnic bread called broa, employing traditional maize varieties, which are preferred by the consumers in detriment of commercial hybrids. In order to evaluate the maize volatiles that can influence consumers’ acceptance of broas, twelve broas were prepared from twelve maize varieties (eleven traditional and one commercial hybrid), following a traditional recipe. All maize flours and broas were analyzed by HS-SPME-GC-MS (headspace solid-phase microextraction) and broas were appraised by a consumer sensory panel. In addition, the major soluble phenolics and total carotenoids contents were quantitated in order to evaluate their influence as precursors or inhibitors of volatile compounds. Results showed that the major volatiles detected in maize flours and broas were aldehydes and alcohols, derived from lipid oxidation, and some ketones derived from carotenoids’ oxidation. Both lipid and carotenoids’ oxidation reactions appeared to be inhibited by soluble phenolics. In contrast, phenolic compounds appeared to increase browning reactions during bread making and, consequently, the production of pyranones. Traditional samples, especially those with higher contents in pyranones and lower contents in aldehydes, were preferred by the consumer sensory panel. These findings suggest that, without awareness, consumers prefer broas prepared from traditional maize flours with higher contents in health-promoting phenolic compounds, reinforcing the importance of preserving these valuable genetic resources.

Progress in pretreatment and analysis of organic Acids: An update since 2010

Organic acids, as an important component of food, have great influence on the flavor, texture, freshness of food. By lowering the pH of food to bacteriostatic acidity, organic acids are also used as additives and preservatives. Because organic acids are crucial to predict and evaluate food maturity, production and quality control, the rapid and sensitive determination methods of organic acids are necessary. This review aims to summarize and update the progress of the determination of organic acids in food samples. Pretreatment methods include simple steps (e.g., "dilute and shoot," protein precipitation, filtration, and centrifugation) and advanced microextraction methods (e.g., hollow fiber liquid phase microextraction, stir bar sorptive extraction and dispersive micro-solid phase extraction). Advances in novel materials (nanomaterial), solvents (ionic liquids and supercritical fluids) and hybrid methods are clearly displayed in detail. Continuous progress which has been made in electrochemical method, two-dimensional chromatography, high resolution mass is thoroughly illustrated.