In order to clarify the inhibiting effect of kelp on the activity of angiotensin converting enzyme, the effects of different additive amount of cellulase and enzymolysis time on the inhibition of angiotensin converting enzyme activity by kelp pulp were investigated by the single factor experiment and response surface optimization test. The results showed that the enzymatic hydrolysis of kelp pulp with cellulase was carried out, and the mathematical model of the inhibition rate Y of ACE activity in kelp enzymatic hydrolysate, the enzyme additive amount X₁ and the enzymolysis time X₂ was established:Y=-114.273 04+0.005 72X₁+1.491 99X₂-3.333 33×10^-7X₁X₂-2.552 00×10^-7X₁²-0.004 47X₂². The optimal enzymolysis condition was obtained as follows:after the kelp was cut and homogenized, 11 060 U·g^-1 cellulase was added at pH 6.0 and the enzymatic hydrolysis was performed at room temperature for 169 min. The inhibition rate of the obtained enzymatic hydrolysate on ACE activity was about 41.43%. The results showed that the enzyme hydrolysate of kelp had a high inhibitory effect on the activity of angiotensin converting enzyme.

In order to improve the titer of Pinus massoniana resin degraded by the fermentation broth of Burkholderia sp.ZYB002, the medium was optimized. The single factor experiment was carried out to determine that 1% glucose was the most suitable carbon source for the fermentation, 0.3% urea and 2% corn flour were the most suitable compound nitrogen sources. The response surface method was used to obtain the optimal ratio of the three main control factors:glucose 0.576%, olive oil 1.81% and inoculation quantity 2.57%. After the optimization, the degradation titer of Pinus massoniana resin was increased to 42.5%. While the optimal ratio was obtained by the BP-GA coupled method:glucose 0.676 3%, olive oil 1.803 4%, inoculation quantity 3.381 3%. After the optimization, the degradation titer of Pinus massoniana resin was increased to 47.4%. The results also showed that compared with the response surface method, the BP-GA coupled method had the better optimization effect, and the titer after the optimization was improved by 38.6% compared with the initial degradation titer. After the optimization by the BP-GA coupled method, the optimal medium composition for the shake-flask fermentation of Burkholderia sp.ZYB002 was:glucose 0.676 3%, corn flour 1.2%, olive oil 1.803 4%, urea (nitrogen content) 0.05%, K₂HPO₄ 0.2%, NaHCO₃ 0.1%, Tween 80 1.0%, and initial pH 8.5. The culture condition was as follows:the fermentation temperature was 30℃, the inoculation quantity was 3.381 3%, the shaking speed was 220 r·min^-1, the loaded liquid was 35 mL(250 mL triangular flask), and the culture time was 36 h.

In order to promote the high-value utilization of bamboo shoots, the cellulose nanocrystal (CNC) was prepared by bamboo shoots rich in cellulose. By taking the green bamboo shoots in Fujian Province as the raw materials, the cellulose nanocrystal of bamboo shoots was prepared by means of crushing, pretreatment and sulphuric acid hydrolysis method. Then, the physical and chemical properties such as water-holding power, oil-holding power and expansive force were studied. The results showed that the bamboo shoot was an appropriate raw material for the preparation of cellulose nanocrystal. After the sulfuric acid hydrolysis, the physicochemical properties of cellulose nanocrystal in bamboo shoots were improved significantly. The yield of the cellulose nanocrystal in bamboo shoots prepared by the sulfuric acid hydrolysis method was 49.54% and the particle size was 91.87 nm. Compared with the crude fibre of bamboo shoots, the water-holding power, oil-holding power and expansive force of cellulose nanocrystal in bamboo shoots were increased by 99.54%, 29.80% and 81.15% respectively.

In order to determine the optimal extraction conditions of amino acid flavor substances in Hypsizygus marmoreus, by using the extraction rate of amino acid nitrogen as the index, the ultrasonic extraction technology of amino acid flavor substances of Hypsizygus marmoreus was optimized by using the single factor experiment and orthogonal experimental design. The results of the single factor experiment showed that the extraction temperature of 70℃, the ratio of material and water of 1:14, and the extraction time of 45 min were more suitable. The results of the orthogonal experiment showed that the factors affecting the extraction rate of amino acid nitrogen were the temperature > the time > the ratio of material and water, and the temperature had the biggest effect, followed by the time, and the ratio of material and water had the least effect. The optimum technological conditions for the ultrasonic extraction of amino acid flavor substances in Hypsizygus marmoreus were as follows:the temperature was 80℃, the time was 30 min, the ratio of material and water was 1:16. Under the optimum conditions, the extraction rate of amino acid nitrogen was (0.915±0.007)mg·g^-1.

The contents of various veterinary drug residues in fresh aquatic products sold in Eastern Fujian were monitored, so as to understand the pollution status of veterinary drug residues in the fresh aquatic products in this region. By means of random sampling, 495 samples of fresh aquatic products were collected from Eastern Fujian including the municipal district of Ningde City, Fu'an, Xiapu, Zhouning, Zherong and Gutian in 2019, and the contents of various veterinary drug residues such as enrofloxacin, ofloxacin and nitrofuran metabolites in the samples were detected by LC-MS/MS after pretreatment. The results showed that many kinds of veterinary drug residues were detected at different levels in the fresh aquatic products sold in Eastern Fujian. Among the collected 495 samples, 121 batches of veterinary drug residues were detected, and the detectable rate was 24.44% (121/495). Among them, there were 15 batches of unqualified products, and the fraction defective was 3.03% (15/495). The unqualified products involved 3 batches of unqualified enrofloxacin, 10 batches of unqualified ofloxacin and 2 batches of unqualified nitrofuran metabolites. The various degrees of contamination of veterinary drug residues in the fresh aquatic products sold in Eastern Fujian indicated that there was a certain degree of veterinary drug abuse in the aquaculture in this region, and the results also showed that the usage frequency of veterinary drug in the aquaculture of fish and bullfrog was higher than that of shrimps, crabs and other aquatic products.

In order to establish a method for the determination of 5 kinds of pesticide residues in strawberries by QuEChERS-gas chromatography, the acetonitrile was used to extract the pesticide from strawberries, and the appropriate amount of ethylenediamine-n-propylsilane (PSA), anhydrous magnesium sulfate, and graphitized carbon black (GCB) were selected for the dispersive solid-phase extraction. GC-ECD detection was conducted on the filtering membrane of the purification solution. The orthogonal test design and variance analysis were conducted by using the software of SPSS statistics version 19. The results showed that the optimal purification combination was A3B3C2, that was, ethylamine-n-propylsilane (PSA) 125 mg, graphite carbon black (GCB) 50 mg, and anhydrous magnesium sulfate 250 mg, and the recoveries of procymidone, prochloraz, chlorothalonil, chlorpyrifos and cyfluthrin were 96.5%, 94.8%, 97.6%, 99.1% and 97.9%, respectively. The method was suitable for the detection of 5 kinds of pesticide residues such as procymidone in strawberries by optimizing the combination of purification agent measured by QuEChERS-gas chromatography.

In order to facilitate the tobacco grading personnel to accurately grasp the concept of tobacco oil moistening degree, from the perspective of tobacco grading practice and according to the definition of oil content in the national standard of flue-cured tobacco (GB2635-1992), by using the sensory analysis and following the production principle of reference sample, 7 grades of reference samples of tobacco oil moistening degree were made, then, the characteristics were described and the grades were sorted. The results of statistical analysis showed that there was a strong consistency in the evaluation and ranking data of the reference samples, and there was a significant difference between the grades, indicating that the reference samples were consistent with repeatability and reproducibility, and had strong applicability.

The content and economic value of levodopa in broad bean flowers in the different varieties of large broad bean were studied to provide reference for the utilization of broad bean flowers. The broad bean flowers extracted from the production of 11 large broad bean varieties were collected to extract the components of levodopa. The content of levodopa in broad bean flowers was determined by liquid chromatography and its economic value was further estimated. The results showed that the content of levodopa in broad bean flowers of Lingxiyicun Variety was the highest (up to 7.57%), and the economic value of levodopa in broad bean flowers was the highest in the variety of Tongcanxian No.8, with the yield reaching 1 893.97 g per 667 m² and the output value reaching 946.99 yuan per 667 m².

In order to study the optimum cultivation density of pod pepper, the effects of different cultivation densities on the growth and yield of pod pepper were studied by using Fujian Pepper King as the experimental material and setting 6 cultivation densities. The results showed that the cultivation density had no effect on the growth process of pod pepper, such as the early flowering season, the initial harvesting period and the final harvesting period. The cultivation density had a great influence on the botanical characteristics of pod pepper. With the increase of cultivation density, the plant height of pod pepper showed a trend of gradual increase, while the plant width and branching number showed a trend of gradual decrease. The cultivation density had an effect on the economic characters of pod pepper. With the increase of the cultivation density, the yield and fruit number per plant significantly decreased, and the average weight of single fruit showed a trend of gradual decrease. The yield of pod pepper showed a trend of gradual increase with the increase of cultivation density when the cultivation density was low and medium. When the cultivation density was 37 050 plant per hm², the yield of pod pepper reached the highest (1 236.7 kg per 667 m²). However, when the planting density was 47 640 plant per hm², the yield decreased significantly.

In order to select the high quality tomato varieties suitable for the soilless cultivation in Nanping City, four tomato varieties including Fenguan, Jinfei strawberry, Juxing steak and Guobao F₁ (CK Group) were introduced in 2018 for the comparative test of soilless cultivation, and the growth period, botanical traits, fruit traits, yield and disease resistance of each variety were comprehensively investigated. The results showed that:the two varieties of Jinfei strawberry and Juxing steak showed good taste, early maturity, long growth period, high yield and significant yield-increasing effect, with the average increase of 104.48% and 101.11% per 667 m² higher than that of the control Guobao F₁, so they were suitable for the soilless cultivation and popularization in the greenhouse of Nanping area. However, Juxing steak had a larger fruit shape, lower fruit setting rate in the later stage and lower yield, so it was not recommended to be planted in the soilless culture of greenhouse in Nanping area. And Guobao F₁ had relatively hard fruit hardness, be resistant to transportation and storage, but low yield and poor taste, so it was also not recommended to be planted in the soilless culture of greenhouse in Nanping area.

As an important part of characteristic towns, the agricultural characteristic towns are the new driving forces for promoting the agricultural supply-side structural reform, an important combination point for promoting the urban-rural integrative development, and an important part for realizing the rural revitalization strategy and securing a decisive victory in building a moderately prosperous society in all respects. As the construction of characteristic towns advanced to the whole and the depth, the agricultural characteristic towns, represented by the rural innovation towns, have showed their progressiveness and adaptability in promoting the rural development. By taking Xiaogang Village as an example, the development mechanism of rural innovation towns in Xiaogang Village and the development foundation of Xiaogang Village under the jointly actions of endogenous factors and external factors were analyzed in depth. The current problems existed in the construction of rural innovation towns in Xiaogang Village, such as the insufficient cultural excavation, insufficient transformation capacity of innovation accumulation, insufficient participation of market resources, and the need for further optimization of the integration of tertiary industry was analyzed. The countermeasures for promoting the characteristic development of Xiaogang Village were put forward including strengthening the planning guidance by enhancing the orientation of the cultural added value, upgrading the overall level of industry by promoting the innovation agglomeration and transformation, optimizing the integration of two-way industrial chain by extending the industrial chain, and strengthening the team construction by attracting the high-quality talents, etc.

The identification of pollution-free agricultural products is one of the main forms of the certification of agricultural products, and the promotion of the identification of pollution-free animal products is of great significance to improve the quality and safety of animal products. By the end of 2019, the effective standard number of pollution-free animal products in Longyan City ranked first in Fujian Province, and the effective standard products were 177, up by 36.2% year on year, and the annual output was 112,600 tons, up by 191.7% year on year. Based on the analysis of the status quo of the identification of pollution-free animal products in Longyan City of Fujian Province, the measures and problems in the identification of pollution-free animal products were summarized, and some countermeasures were put forward, so as to provide reference and thinking for the identification of pollution-free animal products.

With the wide use of pesticides in modern agriculture, pesticide residues in the environment or fruits and vegetables have a huge threat to human health. Therefore, the determination of pesticide residues plays an important role in modern agricultural production activities. The technology of Surface-enhanced Raman Spectroscopy (SERS) has the advantages of simple operation, rapid detection and low cost in the determination of pesticide residues, and has a broad application prospect in the field of pesticide residue determination. In this paper, the basic principle of Raman scattering, the mechanism of Surface-enhanced Raman and the characteristics of SERS-active substrate were briefly introduced, and the research of Surface-enhanced Raman Spectroscopy (SERS) in the determination of pesticide residues was reviewed and prospected by combining with the related literature.

At present, the treatment degree of post-harvest commercialization of pomelo fruit in China was relatively low, which made pomelo fruit easy to suffer from juicy sac granulation and acidification during storage, which seriously affected the commodity value of the fruit. The research progress and development trend of storage and preservation technology of pomelo fruit at home and abroad were summarized from the aspects of low temperature preservation technology, coating preservation technology, preservation film bag technology and other preservation technologies, and the main problems existing in the storage and preservation of pomelo fruit were analyzed. Then, the main research direction of storage and preservation technology of pomelo fruit was prospected in order to provide reference for the research and application of the storage and preservation technology of pomelo fruit.