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The roasted and ground root of the chicory plant (Cichorium intybus), often referred to as chicory coffee, has served as a coffee surrogate for well over 2 centuries and is still in common use today. Volatile components of roasted chicory brews were identified by direct solvent extraction and solvent-assisted flavor evaporation (SAFE) combined with gas chromatography–olfactometry (GC–O), aroma extract dilution analysis (AEDA), and gas chromatography–mass spectrometry (GC–MS). A total of 46 compounds were quantitated by stable isotope dilution analysis (SIDA) and internal standard methods, and odor-activity values (OAVs) were calculated. On the basis of the combined results of AEDA and OAVs, rotundone was considered to be the most potent odorant in roasted chicory. On the basis of their high OAVs, additional predominant odorants included 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon), 2-methylpropanal, 3-methylbutanal, 2,3-dihydro-5-hydroxy-6-methyl-4H-pyran-4-one (dihydromaltol), 1-octen-3-one, 2-ethyl-3,5-dimethylpyrazine, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), and 3-hydroxy-2-methyl-4-pyrone (maltol). Rotundone, with its distinctive aromatic woody, peppery, and “chicory-like” note was also detected in five different commercial ground roasted chicory products. The compound is believed to an important, distinguishing, and characterizing odorant in roasted chicory aroma. Collectively, a group of caramel- and sweet-smelling odorants, including dihydromaltol, cyclotene, maltol, HDMF, and sotolon, are also thought to be important aroma contributors to roasted chicory aroma.

The quantitation of three Strecker aldehydes—2-methypropanal (2-MP), 2-methylbutanal (2-MB), and 3-methylbutanal (3-MB)—from rice bran protein hydrolysate (RBPH) prepared under various conditions were investigated. The preparation conditions included hydrolysis time (0, 0.25, 2, 4, or 8 h), pH adjustment (pH 4.0, 7.0, or 10.0), and sugar addition (sucrose, glucose, or fructose). These conditions provide a significant potential for aroma generation from the Strecker degradation and Maillard reaction. The Strecker aldehyde quantitation was performed using gas chromatography (GC) with cryo-focusing technique. These combined techniques encourage the precise 2-MB and 3-MB quantitation. The highest concentrations of three Strecker aldehydes were found in RBPH that was prepared by alcalase hydrolysis at 4 h with fructose addition (RBPH-F) and adjusted to pH 7.0 before spray drying. Thirty-nine aroma-active compounds of RBPH-F were discovered using solid-phase microextraction coupled with GC-olfactometry.

The pleasant popcorn-like smelling compound 2-acetyl-1-pyrroline (2AP) occurs naturally in many foods but is scarcely used as a flavoring agent due to its great instability. In this work, we evaluate the potential of high amylose corn starch to complex and stabilize 2AP. The methodology was first optimized using model compounds, 2-acetylpyridine and 2-acetyl-2-thiazoline, and then applied to 2AP. Complexes were successfully prepared and characterized using X-ray diffraction, gas chromatography, and differential scanning calorimetry. Loadings of up to 0.504 (±0.071)% 2AP were achieved, and storage studies showed that over half of the flavor was retained after 2 weeks at 0% relative humidity. To our knowledge, this is the first demonstration that 2AP can form amylose inclusion complexes and may lead to a method to effectively stabilize this labile aroma compound.

Roasting is an important unit operation for the development of characteristic chocolate aroma during manufacturing. However, there is an increase in interest in minimally processed chocolate products due to their potential positive health benefits. The odor-important compounds and sensory characteristics of minimally processed (unroasted) and conventionally roasted dark chocolates were determined by gas chromatography-olfactometry, aroma extract dilution analysis (AEDA), and stable isotope dilution analysis (SIDA). Except for acetic acid, all odorants had higher odor-activity values (OAVs) in roasted chocolate. Acetic acid, developed during fermentation and drying, had the highest OAV in both chocolates but was better preserved in unroasted chocolate. Compounds making a greater aroma impact on roasted chocolate compared with unroasted chocolate included dimethyl trisulfide, 2-ethyl-3,5-dimethylpyrazine, and 3-methylbutanal. Nine significant sensory attributes in unroasted and roasted chocolates were identified. Vinegar (aroma) and roasted (aroma and aroma by mouth), sweet (taste), and hardness (texture) attributes differed between unroasted and roasted chocolates. The results of this study enforce the embracement of low thermal processes to showcase the inherent flavor potential of cacao beans but also to support the concept of chocolate “terroir” by potentially preserving important aroma compounds developed during fermentation.

Thermal processing is used to produce most commercial pet foods and treats to improve safety, shelf life, nutritional characteristics, texture, and nutrient digestibility. However, heat treatments can degrade protein quality by damaging essential amino acids, as well as contribute to the Maillard reaction. The Maillard reaction forms melanoidins that favorably improve food qualities (e.g., color, flavor, aroma), but also form Maillard reaction products (MRP) and advanced glycation end-products that may negatively affect health. Because commercial pet diets are frequently fed to domestic cats and dogs throughout their lifetimes, it is critical to quantify MRP concentrations and understand the variables that influence their formation so future diets may be formulated with that in mind. Because few research studies on MRP in pet diets have been conducted, the goals of this study were to measure the MRP in commercial pet foods and treats, estimate pet MRP intake, and correlate MRP with dietary macronutrient concentrations. Fifty-three dry and wet dog foods, dog treats, and cat foods were analyzed for dry matter, organic matter, crude protein, acid-hydrolyzed fat, total dietary fiber, and gross energy using standard techniques. MRP were analyzed using high-performance liquid chromatography and gas chromatography–mass spectrometry. Data were analyzed using the Mixed Models procedure of SAS 9.4. Dry foods had lower reactive lysine concentrations and reactive lysine: total lysine ratios (indicator of damage) than wet foods. Wet foods had more fructoselysine (FRUC) than dry foods; however, dry dog treats contained more FRUC than wet dog treats. The greatest 5-hydroxymethyl-2-furfural (HMF) concentrations were measured in dry and wet dog foods, whereas the lowest HMF concentrations were measured in dry and wet cat foods. Based on dietary concentrations and estimated food intakes, dogs and cats fed wet foods are more likely to consume higher carboxymethyllysine and FRUC concentrations than those fed dry foods. However, dogs fed wet foods are more likely to consume higher HMF concentrations than those fed dry foods. In cats, those fed dry foods would consume higher HMF concentrations than those fed wet foods. We demonstrated that pet foods and treats contain highly variable MRP concentrations and depend on diet/treat type. In general, higher MRP concentrations were measured in wet pet foods and dry treats. While these findings are valuable, in vivo testing is needed to determine if and how MRP consumption affect pet health.Fifty-three dry and wet dog foods, dog treats, and cat foods were analyzed for dry matter, organic matter, crude protein, acid-hydrolyzed fat, total dietary fiber, gross energy, and Maillard reaction product concentrations and estimates of MRP ingestion were calculated. Our results suggest that wet diet consumption will lead to higher Maillard reaction product intake than dry diets.When heat is applied to food, the structure of sugars and proteins are rearranged. Some of the newly formed compounds are Maillard reaction products (MRP). The Maillard reaction can form melanoidins that improve color, flavor, and aroma, but can also lead to the loss of essential amino acids and the formation of advanced glycation end-products that may negatively affect animal health. Most commercial pet foods and treats are heated to improve safety, shelf life, nutritional characteristics, texture, and nutrient digestion, but MRP formation can be a problem. Because commercial pet foods are fed to domestic cats and dogs throughout their entire lives, quantifying MRP and understanding the variables that influence their formation is critical. The goals of this study were to determine the amount of MRP in commercial pet foods and treats, estimate MRP ingestion in pets, and correlate MRP with dietary macronutrient concentrations. Wet foods and dry treats contained more fructoselysine than dry foods, while dry foods contained more 5-hydroxymethyl-2-furfural. According to our findings, wet diets will result in higher total MRP, carboxymethyllysine, and fructoselysine intake than dry diets. While these findings are valuable, in vivo testing is needed to determine if and how MRP consumption affect pet health.

Pan-frying is a popular frying method at home and in many restaurants. Pan-frying stabilities of two frying oils with similar iodine values (IV)—mid-oleic sunflower oil (NuSun oil; IV=103.9) and a commercial canola oil (IV=103.4)—were compared. Each oil sample was heated as a thin film on a Teflon-coated frying pan at ~180°C to a target end point of =20% polymer. High-performance size-exclusion chromatography analysis of the mid-oleic sunflower and canola oil samples indicated that the heated samples contained 20% polymer after approximately 18 and 22 min of heating, respectively. The food oil sensor values increased from zero to 19.9 for the canola sample and from zero to 19.8 for the mid-oleic sunflower sample after 24 min of heating. The apparent first-order degradation rate for the mid-oleic sunflower sample was 0.102±0.008 min-1, whereas the rate for the canola sample was 0.092±0.010 min-1. The acid value increased from approximately zero prior to heating to 1.3 for the canola sample and from zero to 1.0 for the mid-oleic sunflower sample after 24 min of heating. In addition, sensory and volatile analyses of the fried hash browns obtained from both oils indicated there were no significant differences between the two fried potato samples.