Flavor Of Milk Research Articles

Relative effect of warning labels on food choice: Case study with four product categories after the implementation of the Brazilian regulation

Warning labels have been implemented in different countries around the globe, including Brazil, to encourage healthier food choices. The aims of the present study were to evaluate the relative effect of different warning labels, brands and nutrition marketing claims on the food choice after the implementation of the Brazilian front-of package nutrition labelling regulation. Packages of four categories were designed considering the following factors: brand (familiar vs. unfamiliar), nutritional warning (present or absent), textual nutrition marketing claims (present or absent) and visual nutritional marketing claims (present or absent). A total of 850 Brazilian adults were recruited by a marketing agency. Participants were randomly allocated to one of two experimental conditions: black magnifier (n = 403) and black octagon (n = 447). They completed a choice task involving two out of four product categories: chocolate flavored milk, cookies, granola, and iced tea. The packaging was designed considering four factors: The presence of warning labels encouraged product choice in three of the four categories. However, brand and textual nutrition marketing claims had a larger effect. These results suggest the need to introduce comprehensive packaging regulations to reduce the prevalence of nutrition marketing claims on unhealthy products, as well as communication campaigns to raise awareness of the benefits of taking into account warning labels when making food purchases

A comparative study on stability and flavor of additive-free oat milk obtained by different heat pretreatments (blanching and microwave) of oat kernels

Heat pretreatment of oat kernels is necessary in flavor improvement, but its impact on the stability of so-called "clean label" oat milk has not yet been studied. Therefore, two heat pretreatments, including blanching (BC, 90 °C for 5 min) and microwave (MW, 400 W for 5 min), as well as their combination (BC+MW), were compared in this study. The results showed that after the three treatments, the lipase activity of oat kernels was reduced by 50% or more, and stability of oat milk was significantly improved compared to the control. Furthermore, oat milk with BC treatment exhibited the best stability, accompanied by smallest particle size, surface tension, and fluorescence intensity, as well as highest values of zeta potential, apparent viscosity, surface hydrophobicity, and the total content of α-helix and β-sheet, followed by MW and BC+MW. For the flavor compounds analysis results, BC treatment was sufficient to reduce off-flavor compounds (such as hexanal, nonanal, and 2-pentylfuran etc.) in oat milk, achieving the best sensory quality. This study first confirmed the positive effect of appropriate heat pretreatment (BC) of oat kernels on the stability and overall quality improvement of additive-free oat milk.

Effect of fatty acid composition on the volatile compounds of pasteurized milk during low-temperature storage

The change in milk fat during storage greatly influences its flavor. This study investigates the effect of fatty acid composition on milk flavor by analyzing volatile compounds in pasteurized whole milk (PWM) and pasteurized skim milk (PSM) during storage at 4 °C. 33 types of volatile compounds were detected and the content of ketones was highest, followed by esters and aldehydes. Based on variable importance in projection and relative odor activity value, 2-hexenal dimer, acetic acid ethyl ester dimer, acetic acid ethyl ester, and butanal were identified as the key differential volatile compounds. These compounds were found in higher concentrations in PWM than in PSM, indicating a close relationship with the changes in the fatty acid composition of milk fat. Among 11 fatty acids detected in PWM, the content of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) decreased by 0.69 % and 49.1 %, respectively, while the content of monounsaturated fatty acids increased by 46.8 % during 15 days storage, which suggests that the oxidation of SFA and PUFA contributed more to the volatile compound formation. Correlation analysis between fatty acid composition and volatile compounds found that fatty acid C18:2 and C16:0 were strongly associated for 2-hexenal, acetic acid ethyl ester, and butanal. These fatty acids were mainly derived from neutral lipids or phospholipids. These findings provide a new perspective for the formation pathway of milk flavor.

Molecular mechanisms of high aldehyde dehydrogenase production for improved beany flavour regulated by the LuxS/AI-2 quorum sensing system in Limosilactobacillus fermentum A119

Aldehydes cause beany flavor, which is one of the factors limiting the further development of plant-based fermented milks. Limosilactobacillus fermentum (L. fermentum) A119, which has the LuxS/AI-2 quorum sensing (QS) system and producing aldehyde dehydrogenase (ALDH), improves the beany flavor of soy protein-based fermented milk. However, the precise mechanism underlying the production of ALDH and its improvement on the beany flavor remains unclear. The test results indicate that cell density content and ALDH activity were up-regulated with increasing autoinducer-2 (AI-2) signaling molecule. This suggests that ALDH synthesis in L. fermentum A119 may be regulated by the LuxS/AI-2 QS system. Subsequently, the 4D-data-independent acquisition (DIA) proteomics results revealed a total of 378 differentially expressed proteins (DEPs) after 24 h of incubation compared to 2 h incubation. Among them, 236 DEPs were up-regulated, including s-ribosylhomocysteinase (LuxS) and ALDH. Additionally, Western blot analysis confirmed that LuxS/AI-2 QS system successfully mediates the expression of ALDH. Finally, under the catalysis of ALDH, the beany flavor-metabolites benzaldehyde was converted to benzoic acid, which improved the flavor of soy protein-based fermented milk. This study reveals the mechanism of ALDH regulation through the LuxS/AI-2 QS system, provide new insights for reducing beany flavor in soy protein-based fermented milk.

Advantages of UHT in retaining coconut milk aroma and insights into thermal changes of aroma compounds

Coconut milk products are susceptible to bacterial damage, necessitating sterilization methods that often compromise nutrient and aroma integrity. This study investigates the effects of different thermal sterilisation methods on coconut milk aroma using headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). We assessed the impact of pasteurisation (PAS, 70 °C, 25 min), high-temperature sterilisation (HTS, 121.1 °C, 15 min), and ultra-high temperature sterilisation (UHT, 130 °C, 5 s) through clustered heat maps and correlation analyses. Significant differences were observed (p < 0.05), with 37 and 52 substances detected by HS-GC-IMS and HS-SPME-GC-MS, respectively, identifying 12 key aroma compounds. UHT treatment primarily reduced 8 acids, maintaining a compositional structure and sensory profile similar to raw coconut milk. PAS and HTS treatments decreased the sensory intensity of overall coconut milk aroma, creamy, and floral notes, correlating with the presence of 2-heptanol, nonanal, 4-methylvaleric acid, and 2-tridecanone. These methods increased cooked notes, associated with 5-methyl-3-heptanone, 3-butyn-1-ol, hydroxyacetone, and acetoin. Rancidity was linked to acids such as isobutyric acid, isovaleric acid, and heptanoic acid, with high temperatures effectively reducing these compounds. Prolonged temperature changes in PAS and HTS accelerated lipid oxidative degradation and the Maillard reaction, involving free fatty acids in the formation of alcohols, aldehydes, esters, and lactones. These findings provide a theoretical basis for studying coconut milk flavour deterioration.

Characterization and discrimination of donkey milk lipids and volatiles across lactation stages

The lipid and flavor in milk are key factors that affect its quality, which profiles during donkey lactation are not yet clear. In this study, the lipids and volatile compounds (VOCs) in donkey milk from stages of lactation were analyzed by using LC-MS and GC-IMS. A total of 1774 lipids were identified in donkey milk, spanning over 6 major categories and attributed to 30 subclasses. The 233 differentially expressed lipids were identified between donkey colostrum and mature milk, which participate in 20 metabolic pathways, including glycerophospholipid, linoleic acid, and sphingolipid. Additionally, 35 VOCs in donkey milk were identified, including 28.57% aldehydes, 28.57% ketones, 25.71% esters, and 8.57% alcohols. Of these VOCs, 15 were determined to be characteristic flavors in donkey milk, mainly including methyl 2-methylbutanoate, 2-pentanone, and butyl acetate. 11 significantly different VOCs were found between the groups. Acetone, 2-heptanone, and ethyl acetate-m were considered potential discriminatory markers.

Study of volatile flavor derived from lipids degeneration in yak milk based on semiquantitative lipidomics

Milk lipids greatly affect the volatile flavor of milk, and the relationship between lipids and volatile flavor in yak milk was explored in this study. The volatile flavor compounds (VFCs), lipids profile, fatty acids in yak ordinary milk and colostrum were detected with HP/SPME-GC–MS, the semiquantitative lipidomics based on LC-MS/MS, GC–MS, respectively. The VFCs differences in yak milk were closely related to 1-((1 s,3ar,4r,7 s,7as)-4-hydroxy-7-isopropyl-4-methyloctahloctahydro-1h-inden-1-Yl)-ethanone,2,6,6-trimethyl-2,4-cycloheptadien-1-one, pentanal, 2-phenylethyl propionate, octanoic acid methyl ester, diphosphoric acid diisooctyl ester, (Z)-3,4,4-trimethyl-5-oxo-2-hexenoic acid and acetic acid. The volatile flavor in yak milk was well correlated with milk lipids, and TG(4:0_12:3_18:1), TG(6:0_8:0_18:1), TG(4:0_12:3_18:1), TG(12:0_18:2_18:3) and TG(16:0e_18:1_22:5) were the crucial lipid molecules affecting volatile flavor. The degeneration of above lipids by hydrolysis produced some fatty acids and alcohol, then these compounds were further derived into other VFCs especially above crucial 8 molecules. This study provided a theoretical basis for improving the volatile flavor by controlling lipids in yak milk.

Chasing the chill: Unveiling the dynamic flavors and textures of ice cream formulations.

In this study, nine commercial ice creams and four prototypes were assessed. For the sensory analysis, quantitative descriptive analysis (QDA), and temporal dominance of sensations (TDS) methodology were used. According to the QDA results, full-composition ice cream showed significantly higher differences (p < .05) in terms such as vanilla and sweet flavors, brightness, creamy texture and appearance, and viscosity, exhibiting longer melting times. Functional ice creams showed significantly higher differences (p < .05) in terms like viscosity, creamy texture, and appearance. On the other hand, agave fructans in prototype ice creams were found to be able to reduce fat, but not fat and sugar simultaneously, showing a significant decrease (p < .05) in terms such as hardness, crystallized texture, gummy texture, and porosity. Based on the PCA results, the analysis accounted for 75.28% of data variability. Full-composition ice creams and one functional ice cream were related to terms such as viscosity, fatty sensation, creamy texture and appearance, dense, gummy, among others. The rest of the commercial ice creams were related to vanilla and caramel flavor and smell, artificial aftertaste, aerated, porosity, among others. Prototype ice creams were related to hard texture, salty and milk flavor, and crystallized texture. Based on the results of the TDS method, all formulations were found to be significantly dominant (5%) in terms such as vanilla flavor and sweet flavor at the beginning of the test. Formulations containing butyric fat and/or vegetable fat, or agave fructans were significantly dominant (5%) in fatty sensation.

Screening of lactic acid bacteria with the ability to reduce goaty flavor related fatty acids in goat milk

In this study, we conducted sensory evaluation and gas chromatography–mass spectrometry analysis on fermented goat milk samples prepared by 12 strains of lactic acid bacteria (LAB) isolated from goat milk to screen for strains with the ability to reduce the goaty flavor. The bacterial counts of fermented goat milk was 7.07–9.01 log CFU/mL. The electronic nose distinguished fresh goat milk (FGM) and fermented goat milk, and the electronic tongue results showed that Leuconostoc citreum 1, 4, 20, 22, 32, and 57, Latilactobacillus curvatus 144 and 147 imparted fermented goat milk a taste different from FGM. Overall, Leuconostoc citreum 57, Leuconostoc citreum 126, Latilactobacillus curvatus 142, Latilactobacillus curvatus 143, and Latilactobacillus curvatus 147 were screened with the ability to improve the flavor of goat milk. They gave fermented goat milk a goat flavor score lower than or equal to FGM. And the fermented goat milk samples 57, 126, 142, 143, and 147 contained 25, 22, 15, 24, and 17 volatile flavor compounds, respectively, with a greater variety and content of ketones and aldehydes and lower levels of hexanoic acid, octanoic acid, and decanoic acid than FGM. However, the pH and WHC results indicated that the application of these strains as secondary cultures is necessary. Our finding provides basic research data to improve the flavor of goat milk products.

Effect of pH and temperature on the stability of the natural dye from the roselle flower (Hibiscus sabdariffa L.) and its application in flavored milk

Effect of pH and temperature on the stability of the natural dye from the roselle flower (Hibiscus sabdariffa L.) and its application in flavored milk

Characterization of Bubble Pearls from a Mixture of Tapioca and Glucomannan

Boba is a drink originating from Taiwan that has become popular in the Indonesian beverage industry in recent years. This drink consists of a mixture of tea with fruit or milk flavors, with the addition of tapioca-based black chewy textured balls called bubble pearls/boba. Bubble pearls made from tapioca are known to have low nutrition and fiber, so it is necessary to improve their functional characteristics by utilizing local commodities, one of which is porang. Porang (Amorphophallus oncophyllus Prain) as one of the local commodities has the potential to improve the characteristics of bubble pearls. Glucomannan flour from porang tubers has high glucomannan content, quite high fiber content, and can form a gel. This study aims to determine the characteristics of bubble pearl products with the addition of glucomannan flour and to determine the optimum percentage of glucomannan flour and tapioca. The formulation of bubble pearls was carried out using the Simplex Lattice Design method and their physical, chemical, and hedonic characteristics were analyzed. The optimization parameters included water absorption capacity, gumminess level, and dietary fiber content. The optimum formula produced by the Simplex Lattice Design method is in formula 2, bubble pearls with the addition of 25% glucomannan flour which has the highest desirability value of 0.862. Formula 2 consists of a water absorption capacity of 37.08%, a gumminess level of 45.72 gf, and a dietary fiber content of 5.65%. The hedonic values are 5.73 for color (slightly like), 5.7 for aroma (slightly like), 4.8 for hardness (neutral), 4.73 for chewiness (neutral), 5.23 for taste (slightly like), and 5.4 overall (slightly like). Additionally, the water content is 59.97% and the ash content is 1.41%.

Preparation and evaluation of value added functional flavoured milk using spirulina powder

Preparation and evaluation of value added functional flavoured milk using spirulina powder

Characterization of the flavor profile of UHT milk during shelf-life via volatile metabolomics fingerprinting combined with chemometrics

Ultra-high temperature (UHT) milk is popular among consumers. However, its flavor and texture change in its shelf life. Flavor is highly determinative for the success of dairy products and for consumers’ willingness to buy. It is important to milk producers to ensure the optimal flavor of their products in the shelf life. In order to be able to control and predict the flavor quality of UHT milk during the shelf life, this study compared the variations in sensory quality, volatile aroma release and backbone flavor factors and developed a discriminant model to assess flavor quality based on flavouromics data of five competing milk sample during storage. Using partial least squares discriminant analysis (PLS-DA) with Electronic-nose (E-nose) data excellent classification sensitivity and specificity were achieved compared to models based on gas chromatography-mass spectrometry (GC–MS) data. The PLS-DA model using E-nose data exhibited a 100% correct classification rate for the storage period, and a 92% correct rate based on the eight variable importance in the projection (VIP) elements screened for volatile components from different groups. The discriminative model developed herein based on E-nose combined with chemometrics demonstrated advantages such as speed, efficiency, and environmental friendliness. This method shows promise as a precise tool for analyzing aroma changes in UHT milk during its shelf life, and provide support for controlling the flavor substances and milk product development.

Development of iron-fortified chocolate milk for preschool children based on sensory acceptability

Milk is among the most important foods used in the daily diet of children and maybe a suitable option for fortification with minerals such as iron that help reduce iron deficiencies and anemia in children. The objective of the present investigation is to fortify with heme iron from pig blood powder, and pasteurized milk with chocolate flavor and to study its sensory acceptability in a group of children aged 3-5 years. The study variables in milk preparation were iron concentration and sugar content. The compound factorial design and the response optimization allowed for finding an optimal range corresponding to 25% of the recommended dose of iron for children. The formula with the highest acceptability (4.72/5) presented a concentration of 13.65 mg Fe L-1 , 693 mg L-1 vitamin C and 60 g L-1 sugar. According to the physicochemical and microbiological results, the fortified flavored milk complied with regulations and had an approximate shelf life of 5 days. These results showed an alternative for heme iron fortification of chocolate milk, whose content could contribute to the daily requirement of this mineral in children aged 3- 5 years (11 mg of iron per day for a consumption of 250 mL).

Multiomics analysis revealed that the metabolite profile of raw milk is associated with the lactation stage of dairy cows and could be affected by variations in the ruminal microbiota

The nutritional components and quality of milk are influenced by the rumen microbiota and its metabolites at different lactation stages. Hence, rumen fluid and milk samples from 6 dairy cows fed the same diet were collected during peak, early mid- and later mid-lactation. Untargeted metabolomics and 16S rRNA sequencing were applied for analyzing milk and rumen metabolites, as well as rumen microbial composition, respectively. The levels of lipid-related metabolites, L-glutamate, glucose-1-phosphate and acetylphosphate in milk exhibited lactation-dependent attenuation. Maltol, N-acetyl-D-glucosamine, and choline, which are associated with milk flavor or coagulation properties, as well as L-valine, lansioside-A, clitocine and ginsenoside-La increased significantly in early mid- and later mid-lactation, especially in later mid-lactation. The obvious increase in rumen microbial diversities (Ace and Shannon indices) were observed in early mid-lactation compared with peak lactation. Twenty-one differential bacterial genera of the rumen were identified, with Succinivibrionaceae_UCG-001, Candidatus Saccharimonas, Fibrobacter, and SP3-e08 being significantly enriched in peak lactation. Rikenellaceae_RC9_gut_group, Eubacterium_ruminantium_group, Lachnospira, Butyrivibrio, Eubacterium_hallii_group, and Schwartzia were most significantly enriched in early mid-lactation. In comparison, only 2 bacteria (unclassified_f__Prevotellaceae and Prevotellaceae_UCG-001) were enriched in later mid-lactation. For rumen metabolites, LPE(16:0), L-glutamate and L-tyrosine had higher levels in peak lactation, whereas PE(17:0/0:0), PE(16:0/0:0), PS(18:1(9Z)/0:0), L-phenylalanine, dulcitol, 2-(methoxymethyl)furan and 3-phenylpropyl acetate showed higher levels in early mid- and later mid-lactation. Multiomics integrated analysis revealed that a greater abundance of Fibrobacter contributed to phospholipid content in milk by increasing ruminal acetate, L-glutamate and LysoPE(16:0). Prevotellaceae_UCG-001 and unclassified_f_Prevotellaceae provide substrates for milk metabolites of the same category by increasing ruminal L-phenylalanine and dulcitol contents. These results demonstrated that milk metabolomic fingerprints and critical functional metabolites during lactation, and the key bacteria in rumen related to them. These findings provide new insights into the development of functional dairy products.

Integrated analysis of genomics and transcriptomics revealed the genetic basis for goaty flavor formation in goat milk

Goat milk exhibits a robust and distinctive “goaty” flavor. However, the underlying genetic basis of goaty flavor remains elusive and requires further elucidation at the genomic level. Through comparative genomics analysis, we identified divergent signatures of certain proteins in goat, sheep, and cow. MMUT has undergone a goat-specific mutation in the B12 binding domain. We observed the goat FASN exhibits nonsynonymous mutations in the acyltransferase domain. Structural variations in these key proteins may enhance the capacity for synthesizing goaty flavor compounds in goat. Integrated omics analysis revealed the catabolism of branched-chain amino acids contributed to the goat milk flavor. Furthermore, we uncovered a regulatory mechanism in which the transcription factor ZNF281 suppresses the expression of the ECHDC1 gene may play a pivotal role in the accumulation of flavor substances in goat milk. These findings provide insights into the genetic basis underlying the formation of goaty flavor in goat milk. Statement of significanceBranched-chain fatty acids (BCFAs) play a crucial role in generating the distinctive “goaty” flavor of goat milk. Whether there is an underlying genetic basis associated with goaty flavor is unknown. To begin deciphering mechanisms of goat milk flavor development, we collected transcriptomic data from mammary tissue of goat, sheep, cow, and buffalo at peak lactation for cross-species transcriptome analysis and downloaded nine publicly available genomes for comparative genomic analysis. Our data indicate that the catabolic pathway of branched-chain amino acids (BCAAs) is under positive selection in the goat genome, and most genes involved in this pathway exhibit significantly higher expression levels in goat mammary tissue compared to other species, which contributes to the development of flavor in goat milk. Furthermore, we have elucidated the regulatory mechanism by which the transcription factor ZNF281 suppresses ECHDC1 gene expression, thereby exerting an important influence on the accumulation of flavor compounds in goat milk. These findings provide insights into the genetic mechanisms underlying flavor formation in goat milk and suggest further research to manipulate the flavor of animal products.

Identification of aroma-active compounds in milk by 2-dimensional gas chromatography-olfactometry-time-of-flight mass spectrometry combined with check-all-that-apply questions

Understanding consumers' sensory preferences for dairy products is essential. This study employed sensory analysis and instrumental techniques to analyze the flavor of pasteurized milk and UHT milk. There were 6 milk samples with similar fat content (4.0-4.6 g/100 mL) and protein content (3.2-3.8 g/100 mL). Sensory data from consumer tests was collected using check-all-that-apply (n = 100) and 9-point hedonic preferences. Research showed that Chinese consumers could distinguish the flavor of the 2 types of milk, and UHT milk showed a higher preference score, which may be due to the more pronounced milky flavor and sweet taste of UHT milk. A total of 48 aroma-active compounds were sniffed through 2-dimensional gas chromatography olfactometry time-of-flight MS, among which 11 were determined as key aroma-active compounds. Correlation analysis showed that milky odor, sweetness, and aftertaste-milky were positively correlated with γ-dodecalactone and γ-nonanolactone. Cooked and oxidized taste were positively correlated with 1-octen-3-ol and E-2-octenal. This study is important for developing Chinese dairy products and exporting dairy products to China by multinational companies.

Gas chromatography-mass spectrometry and non-targeted metabolomics analysis reveals the flavor and nutritional metabolic differences of cow's milk fermented by Lactiplantibacillus plantarum with different phenotypic

This study comprehensively evaluated the effects of Lactiplantibacillus plantarum T1 and CSK (ropy and non-ropy phenotypes), on flavour, and nutrient metabolites of fermented milks using gas chromatography-mass spectrometry and non-targeted metabolomics. The microrheological analysis showed that the protein gelation time of CSK fermented milk was earlier (5.2 h) than that of T1 (7.0 h), while the fermented milk by T1 had higher elastic modulus. Fermentation by both strains significantly enhanced the antioxidant activity of the fermented milk, including scavenging capabilities against ABTS, DPPH, and hydroxyl radicals. Meanwhile, fermentation by two strains produced various volatile flavor compounds (hexanoic acid, caprylic acid, capric acid, nonanal, decanal, 2-heptanone and 2-nonanone, etc.), and L. plantarum CSK displayed more stronger acid production capacity. In addition, a total of 397 shared metabolites and 81 unique metabolites were identified by untargeted metabolomics analysis of the two groups of fermented milks, mainly including lipids and lipid-like molecules (66, 27.27%), organic heterocyclic compounds (40, 16.53%), phenylketones and polyketones (23, 9.5%), and organic acids and their derivatives (49, 20.25%). Furthermore, both strains significantly elevated the amino acid nutritional levels in the fermented milk, conferred an abundance of active metabolites such as niacin and nicotinamide. During the fermentation, L. plantarum CSK notably produced antioxidant fumaric acid and exhibited higher fatty acid metabolism compared to L. plantarum T1. Overall, this study provides some practical basis for the development of fermented cow's milk with good antioxidant activity and high nutritional quality using different phenotypes of L. plantarum.

Widely Targeted Metabolomic Analysis Revealed the Diversity in Milk from Goats, Sheep, Cows, and Buffaloes and Its Association with Flavor Profiles.

The milk flavor can be attributed to the presence of numerous flavor molecules and precursors. In this study, we employed widely targeted metabolomic analysis techniques to analyze the metabolic profiles of various milk samples obtained from goats, sheep, dairy cows, and buffaloes. A total of 631 metabolites were identified in the milk samples, which were further categorized into 16 distinct classes. Principal component analysis (PCA) suggested that the metabolite profiles of samples from the same species exhibit clustering, while separated patterns of metabolite profiles are observed across goat, sheep, cow, and buffalo species. The differential metabolites between the groups of each species were screened based on fold change and variable importance in projection (VIP) values. Five core differential metabolites were subsequently identified, including 3-(3-hydroxyphenyl)-3-hydroxypropanoic acid, inosine 5'-triphosphate, methylcysteine, N-cinnamylglycine, and small peptide (L-tyrosine-L-aspartate). Through multiple comparisons, we also screened biomarkers of each type of milk. Our metabolomic data showed significant inter-species differences in the composition and concentration of some compounds, such as organic acids, amino acids, sugars, nucleotides, and their derivatives, which may affect the overall flavor properties of the milk sample. These findings provided insights into the molecular basis underlying inter-species variations in milk flavor.

Neural Hyperresponsivity During the Anticipation of Tangible Social and Nonsocial Rewards in Autism Spectrum Disorder: A Concurrent Neuroimaging and Facial Electromyography Study

BackgroundAtypical anticipation of social reward has been shown to lie at the core of the social challenges faced by individuals with autism spectrum disorder (ASD). However, previous research has yielded inconsistent results and has often overlooked crucial characteristics of stimuli. Here, we investigated ASD reward processing using social and nonsocial tangible stimuli, carefully matched on several key dimensions. MethodsWe examined the anticipation and consumption of social (interpersonal touch) and nonsocial (flavored milk) rewards in 25 high-functioning individuals with ASD and 25 neurotypical adult individuals. In addition to subjective ratings of wanting and liking, we measured physical energetic expenditure to obtain the rewards, brain activity with neuroimaging, and facial reactions through electromyography on a trial-by-trial basis. ResultsParticipants with ASD did not exhibit reduced motivation for social or nonsocial rewards; their subjective ratings, motivated efforts, and facial reactions were comparable to those of neurotypical participants. However, anticipation of higher-value rewards increased neural activation in lateral parietal cortices, sensorimotor regions, and the orbitofrontal cortex. Moreover, participants with ASD exhibited hyperconnectivity between frontal medial regions and occipital regions and the thalamus. ConclusionsIndividuals with ASD who experienced rewards with tangible characteristics, whether social or nonsocial, displayed typical subjective and objective motivational and hedonic responses. Notably, the observed hyperactivations in sensory and attentional nodes during anticipation suggest atypical sensory overprocessing of forthcoming rewards rather than decreased reward value. While these atypicalities may not have manifested in observable behavior here, they could impact real-life social interactions that require nuanced predictions, potentially leading to the misperception of reduced interest in rewarding social stimuli in ASD.