No abstract

Flavor quality, including non-volatile and volatile compounds, of hydrolyzed chicken bone extracts (HCBE) during Maillard reaction (MR) was evaluated with HPLC, tasting sensory system, Electronic-Nose (E-nose), and GC-MS. Results showed that flavor amino acids (AA) accounted for 72% to 74% of total free AA in HCBE. Taste of umami increased first and then decreased during MR, while equivalent umami concentration remained at a stable level. Results of taste sensing system and bitter AA showed that MR could reduce the bitter taste of HCBE significantly. E-Nose test showed there are great changes of volatile flavor during MR. And total of 59 volatile compounds were identified in HCBE during MR, which should responsible for the increase of flavor in HCBE. Our results indicated that MR could be used as an effective way to change the flavor compounds in HCBE, and therefore provide a strategy for preparation of meaty flavor enhancer from bone residue as a byproduct of meat industry.

Hot-pressure extraction (HPE), which is regarded as a "green" technology, was applied to extract nutrients (protein, collagen, and minerals) from chicken bone residue (CBR). Amino acids (AA), color, and volatile flavor compounds of chicken bone extract (CBE) were also investigated. Results showed that contents of protein, total soluble solids, minerals, and collagen of CBE were positively correlated with extraction time and temperature. High ratios of protein (83.51%) and collagen (96.81%) were obtained with 135 °C and 120 min. Essential AA accounted for 31.03% to 47.73% of total AA in CBE. The percentage of bitter AA in TAA decreased from 28.94% to 25.02% at 0 min to 20.19% and 21.41% at 120 min, although fresh AA increased from 46.35% to 50.84% (0 min) to 53.14% (120 min) at 130 and 135 °C, respectively, indicating CBE was nutritionally beneficial with good flavor. Color and volatile flavor of CBE improved significantly after extraction, although calcium in CBE (4.2 to 4.8 mg/100 g) was relatively low compared with that of CBR (1078 mg/100 g). It can be concluded that HPE is a promising way to transform CBR into a nutritious flavorant substrate, but it is not an efficient way to extract calcium.