Browning Intensity Research Articles

Improving physicochemical and biological properties of gelatin‐xylooligosaccharide conjugates by Maillard reaction

SummaryMaillard reaction can enhance the functional characteristics of the protein. Herein, we investigated changes in the physicochemical and biological properties of gelatin (GA)‐xylooligosaccharide (XOS) conjugates following Maillard reaction. The results showed that the browning intensity of the conjugates increased with the prolongation of heating time. Additionally, sodium dodecyl sulphate‐polyacrylamide gel electrophoresis revealed some macromolecule polymer formed, and the grafting degree of GA was augmented to 40.05% with prolongation of heating time. GA glycation with XOS decreased α‐Helix content and increased level of β‐Turn level, and exerted a slight impact on contact angle. Moreover, the results of in vitro simulated gastrointestinal digestion analysis showed that the GA‐XOS mixture enhanced resistance to digestion after Maillard reaction for 60 min, affording hydrolysis ratios ranging from 17.86–27.79% and 25.03–35.47% in simulated gastric fluid and intestinal fluid, respectively. The antioxidant ability and heat stability of the conjugates was visibly enhanced following heating treatment. Additionally, increasing the mass of XOS accelerated the antioxidant capacities of GA‐XOS conjugates. The finding will assist the fabrication of GA‐XOS conjugates with highly functional properties by Maillard reaction.

Effectiveness of antioxidants on in vitro regeneration of Musa paradisiaca var. raja to prevent browning and enhance embryo development

The cultivation of raja banana is widespread in Indonesia. The process of increasing banana propagation through in vitro culture encounters a specific issue, namely the occurrence of browning during the initiation stage, which hinders the regeneration process. The objective of this study is to determine the effectivenessof antioxidants on the in vitro regeneration of raja banana to prevent browning and enhance embryo development. The study was conducted using a completely randomized design with the treatment of the antioxidant compounds ascorbic acid (AS) and melatonin (MN). The treatments consisted of control (without antioxidants), ascorbic acid (100 mg L-1, 150 mg L-1, and 200 mg L-1) and melatonin (10 mg L-1, 12 mg L-1, and 14 mg L-1). The results showed that ascorbic acid and melatonin treatment had no significant effect on the percentage of viable explants and the level of browning intensity, but provided significant results on the regeneration process. The application of melatonin at 14 mg L-1 significantly increased callus regeneration. Furthermore, at a concentration of 12 mg L-1 showed the highest callus percentage value compared to other treatments. The melatonin 12 mg L-1 treatment showed the earliest scutellar embryo formation, whereas ascorbic acid at a concentration of 100 mg L-1 resulted in the most optimal regeneration of globular and scutellar embryos. The highest concentrations of ascorbic acid and melatonin inhibit the formation of coleoptilar embryos

The impact of hot-air oven drying combined with Bacillus subtilis K[sbnd]C3 inoculation on quality characteristics and microbial profiles of salted shrimp paste

This study used hot-air oven drying with Bacillus subtilis KC3 inoculation to improve shrimp paste production. The fermentation rate, quality characteristics, as well as microbial profiles, were compared to those produced using sun-drying with/without inoculation. B. subtilis inoculation increased the degree of hydrolysis of shrimp paste (22.3–32.1 %) during fermentation, compared to those without inoculation (12.7–25.4 %), regardless of different drying methods (p < 0.05). The result corresponded to the faster development of shrimp paste characteristics, particularly color and browning intensity of inoculated samples when fermented for the same duration. More abundant halophilic, proteolytic, and lipolytic bacteria (p < 0.05) were also obtained in inoculated samples, confirming accelerated fermentation. Interestingly, there was no difference in proximate composition, pH, and aw among samples (p > 0.05), which were still in the range regulated by the product's standard. However, the protein and lipid degradation products such as nitrogen contents, 5′-nucleotides, free fatty acids or TBARS values, varied among samples, potentially influencing the release of desirable flavor precursors to a certain extent. The inoculation increased microbial richness and evenness/uniformity, according to next-generation sequencing analysis on microbiota profiles. Pearson's correlation also revealed that these microbiota profiles were correlated with several desirable quality characteristics to varying degrees. Thus, combining the inoculation with B. subtilis KC3 can enhance shrimp paste fermentation and quality when produced using an alternative hot-air oven while maintaining quality characteristics. The findings suggested the possibility of achieving a more efficient and consistent production process for shrimp paste.

Influence of reducing sugars and protein‐to‐sugar ratios on volatile profile, pH, and browning intensity of Maillard‐reacted nutritional yeast hydrolysate

SummaryThis study investigated the effects of reducing sugars and protein‐to‐sugar ratios on generating volatile compounds from nutritional yeast hydrolysates after Maillard reaction. Nutritional yeast extract (NYE) was cleaved using Flavourzyme® at an enzyme‐to‐substrate ratio of 0.5% w/w, followed by heat treatment with varying concentrations of reducing sugars (i.e., hexoses: glucose and fructose and pentoses: xylose and ribose). The results showed that pentoses generate higher numbers and concentrations of volatiles than hexoses, especially furans, Strecker aldehydes, and sulphur‐containing compounds such as dimethyl disulphide. However, hexoses produced higher concentrations of pyrazines. Strecker aldehydes and pyrazines served as key aroma‐active compounds in meat aroma. Likewise, sulphur‐containing compounds played an important role in meat aroma due to their low detection threshold. The results showed that reducing sugars significantly impacts the volatile profile of NYE, potentially influencing the formation of meaty aroma compounds. These findings demonstrate the potential of MRPs to enhance meaty flavours due to the presence of volatile compounds with characteristics of cooked meat.

Whey protein isolate‐oligosaccharides conjugates as encapsulants improving stability of L. lactis

SummaryThe aim of this study is to prepare Maillard reaction products (MRPs) with low Browning intensity for microencapsulation of Lactococcus lactis and to improve its processing stability and anti‐digestive ability. In this study, whey protein isolate (WPI) was combined with xylose oligosaccharides (XOS) and feruloyl oligosaccharides (FOs) at 90 °C for 90 min to prepare two Maillard reaction products (MRPs), which were applied to the construction of L. lactis microcapsules. The results showed that WPI‐FOs had a lower Browning intensity and slightly lower intermediate content than WPI‐XOS. Both MRPs showed strong inhibitory effects on the pathogens and probiotics effect on L. lactis. In addition, L. lactis coated with MRPs showed significantly enhanced resistance to heat and mechanical stress. Therefore, this study demonstrated that the Maillard conjugation of WPI with oligosaccharides has the potential to be the encapsulant for probiotic microcapsules.

Characterization of the Non-Volatiles and Volatiles in Correlation with Flavor Development of Cooked Goat Meat as Affected by Different Cooking Methods.

Thai-Native×Anglo-Nubian goat meat cooked by grilling (GR), sous vide (SV), and microwave (MW), was compared to fresh meat (Raw) in terms of flavor development. Non-volatile [i.e., free amino acids, nucleotide-related compounds, taste active values (TAVs) and umami equivalency, sugars, lipid oxidation, Maillard reaction products] and volatile compounds, were investigated. Notably, inosine monophosphate and Glu/Gln were the major compounds contributing to umami taste, as indicated by the highest TAVs in all samples. Raw had higher TAVs than cooked ones, indicating that heat-cooking removes these desirable flavor and taste compounds. This could be proportionally associated with the increase in aldehyde, ketone, and nitrogen-containing volatiles in all cooked samples. GR showed the highest thiobarbituric acid reactive substances (1.46 mg malonaldehyde/kg sample) and browning intensity (0.73), indicating the greatest lipid oxidation and Maillard reaction due to the higher temperature among all cooked samples (p<0.05). In contrast, SV and Raw exhibited similar profiles, indicating that low cooking temperatures preserved natural goat meat flavor, particularly the goaty odor. The principal component analysis biplot linked volatiles and non-volatiles dominant for each cooked sample to their unique flavor and taste. Therefore, these findings shed light on cooking method selection based on desirable flavor and preferences.

Browning Prevention Method in Kepel (Stelechocarpus burahol (Blume) Hook.f. &amp; Thomson) in Vitro Culture

Browning of explants is a common problem in Kepel (Stelechocarpus burahol (Blume) Hook.f. &amp; Thomson) in vitro culture, resulting in low explant in vitro regeneration of Kepel. Using nodal explant, the effect of explant immersion in ascorbic acid, the addition of ascorbic acid to the media, and dark and light incubation conditions were investigated. The browning prevention method was selected based on the delayed browning appearance time, the lowest broning intensity, and the highest percentage of callus. This present study used a completely randomized design with treatment variations: immersion explant in ascorbic acid 100 mg/L, addition of ascorbic acid 100 and 200 mg/L to the media, addition of ascorbic acid 100 and 200 mg/L and activated charcoal 1 g/L to the media, and incubation in dark and light conditions for 28 days. The results showed that the combination of the addition of ascorbic acid 200 mg/L to MS media and incubation in dark conditions were effective browning prevention methods in inhibiting browning appearance time (5 DAP), significantly reducing browning intensity (0.3), and increasing callus growth (100%) of kepel node explants during 28 days of culture. The results of this study are useful in establishing protocols for in vitro culture of Kepel plants, especially at the initiation stage, and can be expected to support the successful conservation of Kepel plants through in vitro propagation. Keywords: Ascorbic acid, Activated Charcoal, Browning, In Vitro Culture, Stelechocarpus burahol

Sensory improvement and antioxidant enhancement in silver carp hydrolysate using prebiotic oligosaccharides: insights from the Maillard reaction.

Our previous studies have highlighted the potential of silver carp hydrolysate (SCH) in managing chronic diseases. Unfortunately, its fishy smell and bitter taste limited consumer acceptance. Prebiotic oligosaccharides are often used as dietary supplements, ignoring their role as carbonyl ligands in the Maillard reaction to enhance food's sensory and antioxidant properties. This study aimed to improve SCH's sensory attributes and investigate its physicochemical properties and antioxidant activities using prebiotic oligosaccharides via the Maillard reaction. The results showed that xylo-oligosaccharide (XOS) had the highest reactivity among the oligosaccharides tested, and it greatly enhanced the taste and flavor of SCH, as well as its antioxidant activities (0.45 to 16.5 times). Specifically, XOS effectively reduced the fishy smell and bitter taste, imparting a caramel-like flavor and overall acceptability to SCH. The improved flavor profile was attributed to the increased presence of sulfur-containing and nitrogen oxide volatile flavor compounds, such as benzothiazole, methional, and furans, which also contributed to antioxidant effects. Sensory evaluation results indicated that SCH obtained from papain exhibited a stronger bitter taste than that obtained from alcalase. Additionally, XOS imparted a reddish-brown color to SCH due to the higher browning intensity. This study is the first to demonstrate that XOS in the Maillard reaction can effectively improve the undesirable flavor and taste of SCH while enhancing its antioxidant activities, providing a theoretical basis for developing SCH as a market-acceptable functional food ingredient.

Flavor improving effects of cysteine in xylose–glycine–fish waste protein hydrolysates (FPHs) Maillard reaction system

A promising way to utilize fish by-products is to develop hydrolysis of fish proteins with enzymes. The obtained fish protein hydrolysates (FPHs) are rich in peptides and amino acids, but bitterness and aroma defects impede further utilization of FPHs. The present study adopted Maillard reaction to improve FPHs’ flavor and illustrated the role of cysteine in this system. We investigated the impact of cysteine (0, 0.25%, 0.5%, 0.75%, and 1%) on the browning intensity, free amino acids (FAAs), molecular weight distribution, structure of MRPs, volatile compounds changes and organoleptic characteristics of xylose–glycine–FPHs Maillard reaction systems. Results showed that the addition of cysteine lowered the browning degree of Maillard reaction products (MRPs) by inhibiting the cross-linking of small peptides and reducing the production of melanin. GC–MS and GC–IMS analysis indicated that cysteine inhibited the formation of furans and nitrogen-containing compounds and facilitated the formation of sulfur-containing compounds contributing to the meaty flavor. Sensory analysis revealed that 0.25–0.75% range of cysteine increased the meaty, caramel, umami, mouthfulness and salty notes, and caused a decrease in bitter taste of the MRPs as confirmed by GC–MS. A highly significant correlation between the organoleptic characteristics and physicochemical indicators of MRPs was found by Mantel test. These results elucidated the influence of cysteine on the formation of Maillard reaction products and will help improve the flavor profile of meat flavorings.Graphical

Effect of 2,4-D and BAP on the Saurauia bracteosa In Vitro Culture

Saurauia bracteosa DC. (Pirdot) is one of the endemic woody plant species that has medicinal properties. The declining population in natural habitats caused this plant as a vulnerable species that need in vitro culture to prevent further extinction. The combination of 2.4-D and BAP as an exogenous PGR influenced the success of woody plant in vitro culture. Therefore, this research aimed to determine the effect of 2.4-D and BAP concentrations on the in vitro response of the S. bracteosa leaf explant. This research used a complete randomized design (CRD) with two factors: (1) the concentration of 2.4-D (0.50; 0.75; 1 mg/L), and (2) the concentration of BAP (B) (1; 2; 3 mg/L). This research consisted of 16 treatments (including a control); each treatment was repeated three times. All data were analyzed statistically using ANOVA, and the significant results will be followed by Duncan’s Multiple Range Test (DMRT). All PGR treatments could not produce a callus growth response, yet all explants showed various responses to browning intensity (0.08–1) and 100% browning. Further research still needs to be done to find the best type of explant and concentrations of PGR that can overcome the recalcitrant explant of Sauraia bracteosa. These results can be valuable information to promote the successful in vitro conservation of Sauraia bracteosa.

Effect of Ascorbic Acid, Activated Charcoal and Dark Incubation on Browning Intensity of Saurauia bracteosa In Vitro Culture

Saurauia bracteosa, also known as Pirdot, is an endemic woody plant of the Actinidiaceae family with medicinal properties. Its population decline in nature has led to a vulnerable status, prompting conservation efforts, such as in vitro culture. Browning poses a significant challenge in the woody plant in vitro culture. Browning inhibitors such as ascorbic acid, activated charcoal and dark incubation can be used to address this issue. This study aims to determine the effect of ascorbic acid, activated charcoal and incubation conditions on browning inhibition of S.bracteosa. The study employed a Completely Randomized Design with 12 treatments on leaf explants, repeated five times. Observations, including the time of browning formation, percentage of browning, intensity of browning and percentage of live explant were carried out for 30 days and analyzed using ANOVA followed by DMRT. The results showed that the addition of activated charcoal in MS media with dark incubation delayed the browning formation time (12.40 DAI) while the adding ascorbic acid in MS media and dark incubation resulted in the lowest browning intensity (0.22). These research findings can serve as a foundational protocol for browning prevention, supporting the successful in vitro conservation of S. bracteosa.

Formation of fluorescent substances and correlation with process flavor changes of dehydrated Maillard reaction intermediates of peanut protein hydrolysates

Maillard reaction intermediates (MRIs) derived from peanut protein hydrolysates (PPH) and xylose (Xyl) were prepared using the water bath combined with spray drying and vacuum drying. The monitoring of free amino content, browning precursors, and taste characteristics was carried out throughout the thermal treatment at low temperature, where the Maillard reaction process was slowed down, and the formation and degradation of MRIs were dynamically balanced at low conversion rates. The reaction between amino compounds and the reducing sugars contributed to the increased taste characteristics during the early phase of Maillard reaction. Fluorescence intensity was reduced after reaching its maximum value and browning intensity was significantly increased during vacuum drying, which confirmed that the Maillard reaction entered into an advanced stage. Vacuum drying also led to a significant increase in the total amount of volatile compounds in the subsequent thermal processing reaction (from 212.93 ng/g to 564.91 ng/g), which demonstrated that the higher fluorescence intensities resulted in the more accumulation of MRIs and better capabilities of flavor formation.

In vitro Anti-Oxidation and Anti-Cholinesterase Activities of Tuna and Chicken Hydrolysates and their Maillard Reaction Products

Objective: To evaluate the anti-oxidation and anticholinesterase activities and cell viability of chicken and tuna hydrolysates and their Maillard reaction products.Material and Methods: Maillard reaction products (MRPs) derived from chicken or tuna hydrolysates were prepared by heating the hydrolysate with glucose at 84°C for 90 minutes. Physical characteristics, ultraviolet (UV) absorbance, browning intensity, protein concentrations, molecular weight distribution, and amino acid profiles of the hydrolysates and MRPs were determined. The anti-oxidation properties of the hydrolysate and MRPs were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Anti-cholinesterase activities were evaluated using Ellman’s method. Cell viability of the samples was evaluated in RAW 264.7 cells.Results: The MRPs presented as brown to dark brown liquids with Brix values ranging from 61.33 to 64.17 °Brix. The pH value ranged from 5.31 to 6.20. The UV absorbance at 294 nm and browning intensity at 420 nm of the MRPs were less than the absorbance of the corresponding hydrolysates. The protein concentrations were 41-44% (hydrolysates) and 18-20% (MRPs). The major constituents of the hydrolysates and MRPs were small molecules (MW&lt;300 Da). The samples exhibited anti-oxidative activity (EC50 2.03 - 3.51 mg/mL) and anti-acetylcholinesterase activity (45-52% inhibition at 0.5 mg/mL). Both hydrolysates and MRPs showed no toxicity to RAW 264.7 cells at concentrations up to 1 mg/mL.Conclusion: Chicken and tuna hydrolysates and their MRPs exhibited mild anti-oxidative and moderate acetylcholinesterase inhibitory activities.

Characterization and emulsifying properties of whey protein isolate-basil seed gum conjugates prepared by Maillard reaction

The present study was conducted to optimize the preparation conditions of whey protein isolate-basil seed gum (WPI-BSG) conjugates resulting from the Maillard reaction in different weight ratios and reaction times. In addition, the stability of the emulsions stabilized by WPI-BSG conjugate was investigated. The covalent attachment of BSG to WPI was effectively confirmed by OPA method, FTIR and fluorescence spectrometry analysis. Results indicated that the maximum zeta potential (-79.83 ± 1.62 mV), emulsifying activity (29.33 ± 2.71 m2/g) and emulsifying stability (45.16 ± 5.14 min) of conjugates were obtained in the weight ratio of 1:2 (WPI to BSG) and reaction time of 2 h. It was also found that a longer heating time may lead to an increase in the browning intensity and a significant decrease in the emulsifying properties of the conjugates. Moreover, according to the results of particle size, zeta potential and creaming index, the emulsions stabilized by WPI-BSG conjugates were more stable than those stabilized by unheated WPI and WPI-BSG mixture. This study indicates that the Maillard reaction can successfully improve the emulsifying properties of WPI. Besides, WPI-BSG conjugates are able to increase physical stability of oil-in-water emulsions.

Colorants and Antioxidants Deriving from Methylglyoxal and Heterocyclic Maillard Reaction Intermediates.

The Maillard reaction is well known for producing antioxidant compounds alongside colored substances. Low-molecular-weight antioxidant intermediates such as maltol (MAL) or norfuraneol (NF) are well described, but it is still unclear which of these Maillard intermediates are the precursors of antioxidant and colored melanoidins-the so-called late stage Maillard reaction products. This study aimed to provide novel insights into the correlation between browning potential and antioxidant properties of reaction products formed during the heat treatment of prominent Maillard reaction intermediates. It was achieved by the incubation of binary reaction systems composed of methylglyoxal (MGO) or NF in combination with furfural (FF), MAL, and pyrrole-2-carbaldehyde (PA) at pH 5 and 130 °C for up to 120 min. Overall, it could be shown that the formation of colored products in the binary NF reaction systems was more efficient compared to those of MGO. This was reflected in an increased browning intensity of up to 400% and a lower conversion rate of NF compared to MGO. The colorants formed by NF and FF or PA (~0.34 kDa and 10-100 kDa) were also found to exhibit higher molecular weights compared to the analogue products formed in the MGO incubations (<0.34 kDa and 10-100 kDa). The incorporation of NF into these heterogenous products with FF and PA resulted in the preservation of the initial antioxidant properties of NF (p < 0.05), whereas no antioxidant products were formed after the incubation of MGO.

Application of soy protein isolate-xylose conjugates for improving the viability and stability of probiotics microencapsulated by spray drying.

Production and consumption of probiotics need to meet many adverse stresses, which can reduce their health-promoting effects on humans. Microencapsulation is an effective technique to improve the biological activity of probiotics and wall materials are also required during encapsulation. Application of Maillard reaction products (MRPs) in probiotic delivery is increasing. This work aims to study the effects of soy protein isolate (SPI)-xylose conjugates heated at different times on the viability and stability of probiotics. SPI-xylose MRPs formed after heat treatment based on changes in the browning intensity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy. After heat treatment, α-helix and β-sheet contents of SPI-xylose mixture shifted from 11.3% and 31.3% to 6.4-11.0% and 31.0-36.9%, respectively, and the thermal stability slightly changed. During spray drying, except for MRP240@LAB, probiotic viability was higher in the MRP-based probiotic microcapsules (21.36-25.31%) than in Mix0@LAB (20.17%). MRP-based probiotic microcapsules had smaller particle sizes (431.1-1243.0 nm vs. 7165.0 nm) and greater intestinal digestion tolerance than Mix0@LAB. Moreover, the MRP-based probiotic microcapsules showed better storability than Mix0@LAB and adequate growth and metabolism capacity. SPI-xylose Maillard reaction products are a promising wall material for probiotics microencapsulation, which can improve bacterial survivability during spray drying and enhance bacterial gastrointestinal digestion resistance. This study sheds light on preparing probiotic microcapsules with superior properties by spray drying. © 2023 Society of Chemical Industry.

In vitro propagation of Geranium wallichianum: An indigenously threatened medicinal plant in Pakistan

Geranium wallichianum is a well-known medicinal plant and has numerous ethnobotanical usages but its population in Pakistan is severely reducing due to overexploitation and over-harvesting. Moreover, the conventional propagation systems are not enough to sustain the population and meet the ever-increasing demand for this plant. Therefore, an efficient propagation system is necessary to conserve and increase the population of this plant. To control browning, citric acid, ascorbic acid and activated charcoal were added to Murashige and Skoog (MS) medium. The 2,4-dichlorophenoxyacetic acid (2,4-D) and naphthaleneacetic acid (NAA) were used in different concentrations to induce the callus while shoot proliferation and root induction were achieved with media supplemented with 6-benzyl aminopurine (BAP), and indole-3-butyric acid (IBA), respectively. Callus was successfully induced in 5.1 days in a medium containing 15 ​μM NAA while the maximum percentage of callus induction (77.78%) was obtained from petiole segments in a medium containing 10 ​μM NAA. Benzyl aminopurine at a concentration of 15 ​μM produced 1.33 shoots per nodal segment compared with 1.0 in the control. Indole butyric acid at a concentration of 10 ​μM increased root length (2.67 ​cm). The results showed a decrease in the browning intensity and an increase in the percentage of survivals in both leaf and petiole cultures (38.88%) and (61.11%) at 0.3 ​g/L activated charcoal compared to control (0% and 5.5%), respectively. Activated charcoal also reduced the total phenolic content of the leaf segment (9.51 ​mg/g) and petiole segment (2.06 ​mg/g). The in vitro produced rooted plantlets were successfully acclimatized in small pots containing peatmoss.

Biotechnological tools for reducing the use of sulfur dioxide in white grape must and preventing enzymatic browning: glutathione; inactivated dry yeasts rich in glutathione; and bioprotection with Metschnikowia pulcherrima

Sulfur dioxide is the most used additive today for preventing browning in grape musts and wines. However, since wine consumers are increasingly interested in healthier wines, the wine industry is keen to reduce its use. Some promising alternatives to sulfur dioxide have been proposed in recent years, including glutathione, both pure and in the form of inactivated yeasts, and Metschnikowia pulcherrima used as a bioprotective agent. Some information exists about the protective effect against oxidation of glutathione but there is very few about the use of bioprotection for that purpose. Supplementation with glutathione, regardless of the commercial form, reduced oxygen consumption and browning intensity when laccase was not present in the grape juice. Metschnikowia pulcherrima also reduced browning intensity in the absence of laccase but increased the total oxygen consumption. However, in the presence of laccase, glutathione and Metschnikowia pulcherrima were not effective enough to adequately prevent the grape juice from browning. Glutathione, both pure and in the form of inactivated yeasts, and Metschnikowia pulcherrima are interesting tools for protecting grape must against browning, and thus reducing the use of sulfur dioxide.

Mathematical optimisation of extruded mixed plant protein-based meat analogues based on amino acid compositions

Developing meat analogues of superior amino acid (AA) profiles in the food industry is a challenge as plant proteins contain less of some essential AA than animal proteins. Mathematical optimisation models such as linear/non-linear programming models were used to overcome this challenge and create high-moisture meat analogues (HMMA) with AA profiles as close as possible to chicken breast meat. The effect on the physiochemical properties and specific mechanical energy (SME) of the HMMA was investigated. The AA content of HMMA was generally lower than chicken. Strong intermolecular bonds present in the globulin fraction could hinder protein acid hydrolysis of HMMA. Plant proteins also affect the HMMA colour as certain AA forms Maillard reaction products with higher browning intensity. Lastly, different characteristics of plant proteins resulted in different SME values under the same extrusion conditions. While mathematical programming can optimise plant protein combinations, fortification is required to match the AA profile of HMMA to an animal source.

Volatilomic evaluation of protein hydrolysates from free-range chicken bones treated with hot-pressure process

The aim of this study was to develop flavoring agents that can be used in the food industry using protein hydrolysates from free-range chicken bones. The chemical composition of chicken bones was determined and showed high protein and lipid content of 26.27 g/100 g and 12.21 g/100 g, respectively. Enzyme hydrolysis was performed with Flavourzyme® (HF), Alcalase® (HA) and a mixture of both in a 1:1 ratio (HFA). Alcalase® has the highest degree of hydrolysis (20.59%), but the flavoring was then prepared with the Flavourzyme® hydrolysate because the volatiles are present in greater quantity and quality for meat flavor. Finally, glucose or xylose was added to the hydrolysates to obtain the flavorings GF and XF. It was found that XF had a higher browning intensity (Maillard reaction) with luminosity values (L*) ranging from 74.24 to 65.17, and the XF flavoring contained eight more aldehydes than the GF flavoring. Thus, the flavoring made with protein hydrolysate of free-range chicken bones added with xylose showed the aromatic potential of meat and can be used as an ingredient in the food industry.