Microwave heating and conduction heating pork belly: Influence of heat transfer modes on volatile compounds and aroma attributes

This work was conducted to compare the differences in odor attributes and the formation causes of pork belly cooked by different heating modes and the feasibility of achieving convenient and delicious cooking of stir-fried pork cuisines by modifying the heat transfer mode of the microwave.The effects of traditional pan-heating(TH),microwave heating(MH),and microwave combined with conduction heating(MH+CH)on sensory aroma attributes,aroma profile,free fatty acids,and volatile compounds of pork belly were investigated.The results showed that the pork belly heated by TH had the lowest total amount of stable volatile compounds(1695.41μg/kg)and contents of free fatty acids(751.44 mg/100g),but the balanced distribution and the rich contents of volatile compounds derived from thermal processing resulted in the better aroma quality of pork belly.In contrast,although the pork belly cooked by MH had higher free fatty acids contents(1215.32 mg/100g)and the highest volatile compounds(5410.56μg/kg),due to the cell destruction effect and the molecular movement acceleration of microwave,the contents of volatile compounds derived from spices were too high,leading to the disharmony of aroma characteristics.However,the pork belly cooked with MH+CH not only promoted the production of free fatty acids(1434.23 mg/100g),but also increased the generation and retention of pork characteristic aroma by changing the heating modes.Compared with MH,it enhanced the uniformity of aroma distribution and improved the overall aroma similarity to TH.

Taste characteristic and the mechanism of light-colored Maillard reaction products derived from gluten hydrolysate

Light color and savory flavor are difficult to be integrated in‘Thermal Process Flavoring’through traditional Maillard reaction.A light-colored seasoning from gluten peptide-glucose system was prepared through gradient temperature-elevating Maillard reaction with extra-added L-cysteine.Greater saltiness and umami enhancement effect of Maillard reaction products(MRPs)were observed from weaker reaction,while lower temperature and longer heating time were conducive to yield kokumi-taste compounds.With the addition of L-cysteine,intensities of fluorescence and UV-VIS absorption of MRPs were weakened.An inhibition of browning and a decrease ofα-dicarbonyls concentration caused by L-cysteine were observed.The addition of L-cysteine also led to an increase of peptides below 500 Da(from 53.27 mg/mL to 56.50 mg/mL)and a decrease of cross-linking products in 1-3 kDa,which accounted for superior umami and gentle kokumi attribute of the light-colored products compared with the MRPs without L-cysteine addition.

Exogenous glutamic acid effectively involved in N-(1-deoxy-D-galulos-1-yl)-glutamic acid degradation for simultaneous improvement of both milk-like and baking flavor

This research elucidated the reason of flavor deficiency during the thermal degradation of glutamic acid(Glu)-galactose(Gal)Amadori rearrangement product(GG-ARP)and the solution.The flavor formation from GG-ARP during the thermal degradation was investigated.Compared to the volatile compounds in Glu-Gal Maillard reaction products(GG-MRP),pyrazines in the volatile compounds derived from GG-ARP were restrained.The disadvantage in evolution asynchrony and content sufficiency ofα-dicarbonyl compounds and Glu in the GG-ARP model limited the pyrazines formation.With the addition of Gal,the asynchronous effect was further exacerbated,and the furans in the GG-ARP-Gal model(956.81μg/L,120℃,60 min)were more significantly dominant among the volatile flavor compounds than in the GG-ARP model(454.98μg/L,120℃,60 min),while the pyrazines were still missing.Whereas,the extra-added Glu in the GG-ARP model could offset the deficiency of amino acids growth afterα-dicarbonyl formation and promote the formation of pyrazines(74.47μg/L,120℃,60 min).Meanwhile,the formation of diketones(92.96μg/L,120℃,60 min)was promoted.The addition of Glu enhanced both milk-like and baking flavor of the GG-ARP system simultaneously.Formulated GG-ARP-Glu mixture was proposed to promisingly achieve the controlled formation of process flavors for baked foods with both desirable milk-like and baking scent.