Study On Composition Of Loquat Peel And Development Of Loquat Peel Beverage

Loquat(Eriobotrya japonica Lindl.),which belongs to the family Rosaceae,subfamily Maloideae,is a kind of Non-climacteric fruit.The fresh loquat is usually processed into maconochie,dried fruits and beverage.During the process,the uneatable parts,which is about 20%?40%of the fruit,are regarded as useless,and therefore being discarded.This means a large portion of this fruit is wasted,and may cause severe damage to the environment.Containing a large amount of functional elements,utilizing the peel of loquat is of great importance in not only reducing environmental pollutions,but increasing the added value of this fruit with significant economic value.To study the peel of loquat and its potential in future food product,two series of research are performed in this thesis.In the first part,the fundamental investigation in the chemical components of the peel of loquat is performed,while in the second part,products based on the peel of loquat are developed and examined.The detailed summary of the thesis is the following:1.In this thesis,the basic nutritional chemicals and the functional elements in the peel of loquat are characterized by using chemical methods.The characterization of the basic nutritional chemicals proves that this peel is of high nutritional value,and has the potential to be made into food products.The concentrations of polyphenols,flavonoids,triterpenoid acid are 6504.99 mg GAE/100g DW,781.89 mg Rutin/100g DW,4366.76 mg UA/100g DW,respectively,which confirm its value as the resource for functional products.2.By using Headspace solid-phase micro-extraction combined with gas phase mass spectrometry(HSME-GC-MS)on fresh,naturally dried,heated air dried peels,the volatile components in the three sets of samples are analyzed and compared.The numbers of the types of volatile components are found to be 35(fresh),73(heated air dried)and 83(naturally dried).The major contributors to the aroma of the peels before and after drying are aldehydes(hexanal,trans-2-hexene aldehyde and nonyl aldehyde).More intense and additional volatile components can be found in the dried samples,and similarities in the volatile components can be found between the two dried sample sets.3.The optimal extraction process for dried peels of loquat has been obtained to achieve the highest concentration of polyphenols by performing orthogonal analysis.The process employs the peel with the particle size of 250 ?m,the peel is then mixed with pure water with the material-to-liquid ratio at 1:25,and the extraction is performed at 95? for 1.5 hours.The overall extraction ratio of polyphenols is 8.247±0.133%.The Total antioxidant capacity(T-AOC)and DPPH scavenging activity of the extracted materials are less in general compared with Vc.However,when the concentration of the sample reaches 2.5 mg/mL,the DPPH scavenging activity can be as high as 92.75%,which are comparable with Vc.The median elimination concentration(IC50)of DPPH equals to 0.786 mg/mL.Moreover,the scavenging activity of hydroxyl radical outmatches Vc.At the concentration of 5 mg/mL,the scavenging activity of hydroxyl radical reaches 94.69%and IC50 reaches 0.866 mg/mL.4.The orthogonal experiment is done by adding extractions from loquat peels and mint leaves.A tasty drink made of the peel of loquat is demonstrated.A sensory evaluation performed in the drink of loquat peel and two kind of drinks in market,which show the sensory characteristics of the drink of loquat peel,The concentrations of polyphenols,flavonoids,triterpenoid acid,free amino acid in this drink are 1.694±0.018 mg/mL,0.680±0.124 mg/mL,1.947±0.106 mg/mL,5.361±0.063 mg/mL,respectively.This work serves as a guideline for future product development using the peel of loquat.