Health-related Compounds Research Articles

High-quality genome of a modern soybean cultivar and resequencing of 547 accessions provide insights into the role of structural variation.

Soybean provides protein, oil and multiple health-related compounds. Understanding the effects of structural variations (SVs) on economic traits in modern breeding is important for soybean improvement. Here we assembled the high-quality genome of modern cultivar Nongdadou2 (NDD2) and identified 25,814 SV-gene pairs compared to 29 reported genomes, with 13 NDD2-private SVs validated in 547 deep-resequencing (average = 18.05-fold) accessions, which advances our understanding of genomic variation biology. We found some insertions/deletions involved in seed protein and weight formation, an inversion related to adaptation to drought and a large intertranslocation implicated in a key divergence event in soybean. Of 749,714 SVs from 547 accessions, 6,013 were significantly associated with 22 yield-related and seed-quality-related traits determined in ten location × year environments. We uncovered 1,761 associated SVs that hit genes or regulatory regions, with 12 in GmMQT influencing oil and isoflavone contents. Our work provides resources and insights into SV roles in soybean improvement.

Intra-annual and regional variability of the oleic acid and linoleic acid content of pumpkin seed oil over a 10-year period

Pumpkin seed oil, extracted from roasted and hulled pumpkin seeds, is prized for its distinct nutty flavor and deep amber color. Its significance in gastronomy lies in its rich flavor profile and nutritional benefits, which enhance dishes with both taste and health-promoting properties. Despite a notable increase in production, particularly in Croatia and other regions, there remains a gap in research regarding how factors such as production year and geographic origin influence its quality and health-related compounds. In this study, we analyzed the fatty acid composition of 928 samples of pumpkin seed oil from Croatia, Slovenia, Austria, and Hungary, produced between 2014 and 2023, using GC-FID, with a focus on linoleic and oleic acids. Our findings revealed significant year-to-year variability, particularly evident in 2019 samples, which exhibited higher oleic acid and lower linoleic acid content, resulting in the highest oleic acid to linoleic acid ratio. Additionally, cold-pressed oils showed a slightly higher ratio, and a significant regional influence was observed, with Austrian oils having a lower ratio compared to those from Croatia and Slovenia. This observed variation may be attributed to changing climatic conditions or shifts in producer practices, though further research is needed to validate these hypotheses.

Farm to Fork Stability of Phytochemicals and Micronutrients in Brassica oleracea and Allium Vegetables.

Brassica oleracea and Allium vegetables are known for their unique, family specific, water-soluble phytochemicals, glucosinolates, and S-alk(en)yl-l-cysteine sulfoxides, respectively. However, they are also important delivery systems of several other health-related compounds, such as carotenoids (lipid-soluble phytochemicals), vitamin C (water-soluble micronutrient), and vitamin K1 (lipid-soluble micronutrient). When all-year-round availability or transport over long distances is targeted for these often seasonal, locally grown vegetables, processing becomes indispensable. However, the vegetable processing chain, which consists of multiple steps (e.g., pretreatment, preservation, storage, preparation), can impact the nutritional quality of these vegetables corresponding to the nature of the health-related compounds and their susceptibility to (bio)chemical conversions. Since information about the impact of the vegetable processing chain is scattered per compound or processing step, this review targets an integration of the state of the art and discusses needs for future research. Starting with a discussion on substrate-enzyme location within the vegetable matrix, an overview is provided of the impact and potential of processing, encompassing a wide range of (nonenzymatic) conversions.

Impact of frozen storage and pretreatment conditions on health-related compound stability kinetics in leeks and Brussels sprouts

Frozen vegetable chain variables can impact health-related compounds and their corresponding unique (bio)chemical reactions. To delve into this dynamism, kinetic shelf life studies were undertaken, focusing on several compounds (vitamin C, vitamin K1, carotenoids, glucosinolates, S-alk(en)yl-l-cysteine sulfoxides (ACSOs)) present in Brussels sprouts and leek. Frozen storage was conducted after industrial freezing and performed at −7, −15, −20 and −40 °C over one year. Glass transition temperature was about −24 °C for leek (Tg’) and about −27 °C for Brussels sprouts (Tg”). Overall, compound stability was higher when stored close to the glass transition temperature, influenced by (bio)chemical conversations related to substrate-enzyme location. Losses of 0–30% glucosinolates, 17–100 % vitamin C in blanched Brussels sprouts and 7–80% ACSOs, 87–100% vitamin C, 39–100% carotenoids in unblanched diced leeks were determined. Mathematical models were used to describe and compare the stability of these compounds as impacted by frozen storage. Additionally, different pretreatments (blanching, pureeing) were applied before freezing. Pretreatment type impacted initial compound concentrations, but had no impact on compound behavior during frozen storage of nine months, except for vitamin C which was stabilized by blanching but destabilized by pureeing. Overall, vitamin K1 was the only compound not impacted by storage temperature or pretreatment type.

In-depth exploration of the genomic diversity in tea varieties based on a newly constructed pangenome of Camellia sinensis.

Tea, one of the most widely consumed beverages globally, exhibits remarkable genomic diversity in its underlying flavour and health-related compounds. In this study, we present the construction and analysis of a tea pangenome comprising a total of 11 genomes, with a focus on three newly sequenced genomes comprising the purple-leaved assamica cultivar "Zijuan", the temperature-sensitive sinensis cultivar "Anjibaicha" and the wild accession "L618" whose assemblies exhibited excellent quality scores as they profited from latest sequencing technologies. Our analysis incorporates a detailed investigation of transposon complement across the tea pangenome, revealing shared patterns of transposon distribution among the studied genomes and improved transposon resolution with long read technologies, as shown by long terminal repeat (LTR) Assembly Index analysis. Furthermore, our study encompasses a gene-centric exploration of the pangenome, exploring the genomic landscape of the catechin pathway with our study, providing insights on copy number alterations and gene-centric variants, especially for Anthocyanidin synthases. We constructed a gene-centric pangenome by structurally and functionally annotating all available genomes using an identical pipeline, which both increased gene completeness and allowed for a high functional annotation rate. This improved and consistently annotated gene set will allow for a better comparison between tea genomes. We used this improved pangenome to capture the core and dispensable gene repertoire, elucidating the functional diversity present within the tea species. This pangenome resource might serve as a valuable resource for understanding the fundamental genetic basis of traits such as flavour, stress tolerance, and disease resistance, with implications for tea breeding programmes.

Improvement of the Quality of Wild Rocket (Diplotaxis tenuifolia) with Respect to Health-Related Compounds by Enhanced Growth Irradiance.

For healthier human nutrition, it is desirable to provide food with a high content of nutraceuticals such as polyphenolics, vitamins, and carotenoids. We investigated to what extent high growth irradiance influences the content of phenolics, α-tocopherol and carotenoids, in wild rocket (Diplotaxis tenuifolia), which is increasingly used as a salad green. Potted plants were grown in a climate chamber with a 16 h day length at photosynthetic photon flux densities varying from 20 to 1250 μmol m-2 s-1. Measurements of the maximal quantum yield of photosystem II, FV/FM, and of the epoxidation state of the violaxanthin cycle (V-cycle) showed that the plants did not suffer from excessive light for photosynthesis. Contents of carotenoids belonging to the V-cycle, α-tocopherol and several quercetin derivatives, increased nearly linearly with irradiance. Nonintrusive measurements of chlorophyll fluorescence induced by UV-A and blue light relative to that induced by red light, indicating flavonoid and carotenoid content, allowed not only a semiquantitative measurement of both compounds but also allowed to follow their dynamic changes during reciprocal transfers between low and high growth irradiance. The results show that growth irradiance has a strong influence on the content of three different types of compounds with antioxidative properties and that it is possible to determine the contents of flavonoids and specific carotenoids in intact leaves using chlorophyll fluorescence. The results may be used for breeding to enhance healthy compounds in wild rocket leaves and to monitor their content for selection of appropriate genotypes.

The nutritional composition of key apricot varieties cultivated in Türkiye with a focus on health-related compounds

Türkiye’s favorable geographical location and diverse climatic conditions provide it an ideal host for a wide range of fruit species. In this content, apricots have garnered significant global attention. In this study, local varieties such as Hasanbey, Hacıhaliloğlu, Kabaaşı, and Şalak were examined, alongside foreign varieties commonly cultivated in coastal regions, specifically Mikado and Mogador. It was found that domestic varieties are notably different from foreign varieties in terms of their health-related components. Fruits from various varieties sourced from significant apricot-producing provinces were investigated. The study revealed a range in total carotenoid content from 5.59 to 10.3 mg/kg, antioxidant activity spanning 478.5 to 1969 mgTE/kg, and total phenol content fluctuating between 122 and 771 mgTE/kg. The ‘Şalak’ distinguishes itself significantly from others due to its elevated phenolic content, leading to a correspondingly higher level of antioxidant activity. In conclusion, it has been observed that the antioxidant content in this variety is significantly higher (approximately 4 times higher). The study results unequivocally demonstrate that, beyond the significance of cultivation location, genotype plays a pivotal role as an essential determinant in relation to the evaluated quality features.

Impact of refrigerated storage on (bio)chemical conversions of health-related compounds in pretreated, pasteurized Brussels sprouts and leek

Vegetable processing often consists of multiple processing steps. Research mostly focused on the impact of individual processing steps on individual health-related compounds. However, there is a need for more holistic approaches to understand the overall impact of the processing chain on the health potential of vegetables. Therefore, this work studied the impact of pretreatment (relatively intact versus pureed vegetable systems), pasteurization and subsequent refrigerated storage (kinetic evaluation) on multiple health-related compounds (vitamin C, vitamin K1, carotenoids, glucosinolates and S-alk(en)yl-L-cysteine sulfoxides (ACSOs)) in Brussels sprouts and leek. It could be shown that differences introduced by different types of pretreatment were not nullified during pasteurization and refrigerated storage. Clearly, enzymatic conversions controlled during pretreatment resulted in different health-related compound profiles still observable after pasteurization. Moreover, about −42% and −100% relative concentration differences of ACSOs and dehydroascorbic acid, respectively, were detected immediately after pasteurization, while glucosinolates concentrations decreased by about 47% during refrigerated storage. All other compounds were stable during pasteurization and refrigerated storage.

Controlling (bio)chemical conversions of health-related plant-based compounds by processing: The case of Brussels sprouts and leek

Brussels sprouts and leek are suppliers of multiple health-related compounds, yet understudied on how processing impacts their concentration. In this study, the plant tissue structure was altered by processing to direct endogenous enzyme-substrate interactions. For this, both conventional and novel processing techniques were employed. Heating intact vegetables prior to high shear mixing resulted in relatively good preservation of health-related compounds, attributed to a prompt inactivation of endogenous enzymes. Oppositely, high shear mixing prior to heating facilitated over 82% conversion for both vitamin C, S-alk(en)yl-L-cysteine sulfoxides (ACSOs) and glucosinolates. Pulsed electric field (PEF) treatment prior to heating, resulted in ±25% ACSOs conversion, yet no glucosinolates conversion. PEF treatment effectiveness is attributed to substrate-enzyme localization in the matrix and cell size. Vitamin K1 remained relatively stable during all treatments. It was postulated that higher concentrations of vitamin C protect carotenoids against oxidation pointing to interaction effects among health-related compounds. Industrial relevance textThis research paper gives more insight into how (the sequence of) commonly used pretreatments (e.g. heating, mixing) and more innovative pretreatments (e.g. pulsed electric field) can have an impact on the health potential of vegetables. The considered vegetables (Brussels sprouts and leek) are highly industrial relevant and insights may be extrapolated to other vegetables of these large plant families. By understanding which (bio)chemical reactions can occur during certain pretreatments (e.g. degradation or potential formation of health-related compounds), industry can perform pretreatments more thoughtfully and consequently steer the health potential of vegetable products. Pulsed electric fields are currently not commonly used in vegetable processing. However, this processing technique can enable certain enzymatic conversions, of which some could result in formation of health beneficial compounds, without losing the vegetable structure. Therefore, applying pulsed electric fields in the vegetable processing industry could have large potential. The aim of this research is to open the door to more research on pulsed electric fields applied on vegetables, so the vegetable industry becomes acquainted with using this technique.

Effects of different drying treatments on the microstructure, free amino acids, volatile compounds and antioxidant activity of Flammulina velutipes root.

Drying treatments are an effective method of preserving the beneficial properties of postharvest mushrooms. The effects of natural-air drying (ND), hot-air drying (HD), vacuum-freeze drying (FD), heat pump drying (HPD) and microwave-vacuum drying (MVD) on the microstructure, flavor- and health-related compounds of F. velutipes root were investigated. The results showed that FD had the least impact on the microstructure of F. velutipes root and its original porous fiber structure appeared complete. It also possessed the highest content of volatile compounds. MVD gave the highest contents of umami amino acids, total phenolics and total flavonoids, and its extract exhibited high antioxidant activity. In addition, different drying treatments had significant effect on the chemical components of F. velutipes root, with FD and MVD may be the potent drying strategies for preservation of flavor and nutraceuticals respectively. Therefore, our results provided essential data support for F. velutipes root processing and functional product development.

Immunomodulatory and Antioxidant Effects of Spray-Dried Encapsulated Kale Sprouts after In Vitro Gastrointestinal Digestion.

The health-related compounds present in kale are vulnerable to the digestive process or storage conditions. Encapsulation has become an alternative for their protection and takes advantage of their biological activity. In this study, 7-day-old Red Russian kale sprouts grown in the presence of selenium (Se) and sulfur (S) were spray-dried with maltodextrin to assess their capacity to protect kale sprout phytochemicals from degradation during the digestion process. Analyses were conducted on the encapsulation efficiency, particle morphology, and storage stability. Mouse macrophages (Raw 264.7) and human intestinal cells (Caco-2) were used to assess the effect of the intestinal-digested fraction of the encapsulated kale sprout extracts on the cellular antioxidant capacity, the production of nitric oxide (NOx), and the concentrations of different cytokines as indicators of the immunological response. The highest encapsulation efficiency was observed in capsules with a 50:50 proportion of the hydroalcoholic extract of kale and maltodextrin. Gastrointestinal digestion affected compounds' content in encapsulated and non-encapsulated kale sprouts. Spray-dried encapsulation reduced the phytochemicals' degradation during storage, and the kale sprouts germinated with S and Se showed less degradation of lutein (35.6%, 28.2%), glucosinolates (15.4%, 18.9%), and phenolic compounds (20.3%, 25.7%), compared to non-encapsulated ones, respectively. S-encapsulates exerted the highest cellular antioxidant activity (94.2%) and immunomodulatory activity by stimulating IL-10 production (88.9%) and COX-2 (84.1%) and NOx (92.2%) inhibition. Thus, encapsulation is an effective method to improve kale sprout phytochemicals' stability and bioactivity during storage and metabolism.

Breakthrough Analysis of Chemical Composition and Applied Chemometrics of European Plum Cultivars Grown in Norway

The aim of this study was to find the chemical parameters for the differentiation of plum cultivars grown along the fjord areas of Western Norway and Eastern Norway, having specific agroclimatic conditions. Chemical analysis of the fruits confirmed the contents of 13 quantified elements, 22 sugar compounds, 11 organic acids, 19 phenolic compounds, and antioxidant activity in 68 plum cultivars. Dominated contents were noted for nitrogen (with the maximum mean value of 3.11%), potassium (8055.80 mg/kg), and phosphorous (7878.88 mg/kg). Averagely, the highest level of sugars was determined for glucose (244.46 g/kg), fructose (197.92 g/kg), sucrose (208.25 g/kg), and sorbitol (98.02 g/kg), organic acids for malic acid (24.06 g/kg), and for polyphenol compounds were 5-O-caffeoylquinic acid (66.31 mg/kg), and rutin (58.06 mg/kg). Applied principal component analysis has been useful for distinguishing the plum cultivars from three areas in Norway where copper, iron, potassium, magnesium, manganese, and sodium; sucrose, ribose, maltose, and raffinose; p-hydroxybenzoic acid, rutin, ferulic acid, kaempferol 7-O-glucoside, p-coumaric acid, and 5-O-caffeoylquinic acid were the most influential. In regard to human health and future breeding work that will have the aim to produce functional food with high health-related compounds, the plum cultivar ‘Mallard’ should be underlined due to the high level of elements, ‘Valor’ due to high sugar content, ‘Helgøyplomme’ due to content of organic acids, and ‘Diamond’ due to the content of phenolic compounds.

The Introduction of Allochthonous Olive Variety and Super High-Density System in the Abruzzo Region: A Study on Olive Oil Quality

The transition to a sustainable economic and environmental management of olive oil sector needs to be implemented in both national and regional territories through the introduction and development of innovative growing systems and variety. In this study, the olive oil quality parameters of local and allochthonous varieties cultivated in different orchards located in the Abruzzo region (Italy), using traditional and super high-density systems, were analyzed. Frantene, Lecciana, Koroneiki, and a mix of Arbequina and Lecciana provided olive oils rich in flavonoids and secoiridoids compounds with respect to the local varieties Frantoio, Leccino, and a mix of Dritta, Leccino, and Pendolino. Oleic/linoleic ratio was influenced by cultivar and training systems with super high-density olive oils rich in oleic acid. Frantene showed a peculiar fatty acid profile different from cultivars grown in the same location; moreover, interesting similarities were found between Frantene and the mix of Dritta, Leccino, and Pendolino in terms of health-related compounds. The potential development of innovative sustainable training system to improve olive oil quality was highlighted. The study's results identify olive varieties suitable for super high-density systems spread in the Abruzzo region, representing a valid alternative for the olive growers to improve both the quality of the olive oil, as well as the company's income.

Changes in phenolics and flavonoids in amaranth and soybean sprouts after UV-C treatment.

Sprouts, mainly from cereals, legumes, and some pseudo-cereals, are rich in nutrients and contain biocompounds, making them attractive for consumption. This research study aimed to develop treatments with UV-C light in soybean and amaranth sprouts and evaluate their effect on biocompounds content, compared with chlorine treatments. UV-C treatments were applied at distances of 3 and 5cm and times of 2.5, 5, 10, 15, 20, and 30min, whereas chlorine treatments were applied as immersion in solutions at 100 and 200ppm for 15min. Phenolics and flavonoid content were higher in UV-C-treated sprouts than in those treated with chlorine solutions. Ten biocompounds were identified in soybean sprouts, with increasing in apigenin C-glucoside-rhamnoside (105%), apigenin 7-O-glucosylglucoside (237%), and apigenin C-glucoside malonylated (70%) due to UV-C application (3cm, 15min); for amaranth sprouts, five biocompounds were identified, with higher contents of p-coumaroylquinic acid (17.7%) after UV-C treatment (3cm, 15min). The best treatment to achieve the highest bioactive compounds concentration was UV-C at a distance of 3cm for 15min, without significant modification on the color parameters, Hue and chroma. PRACTICAL APPLICATION: UV-C can be used to increase the biocompound content in amaranth and soybean sprouts. Nowadays, there is UV-C equipment available for industrial applications. In this way, sprouts may be maintained as fresh through this physical technology, and they will retain or increase the concentration of health-related compounds.

Changes in the content of glucosinolates, polyphenols and carotenoids during lactic-acid fermentation of cruciferous vegetables: A mini review.

Cruciferous vegetables are considered functional foods because of their content of health-related compounds. They are grown and consumed in various cultures around the world. Fermentation as a preservation method for cruciferous vegetables has been used since ancient times. This process results in fermented products that have a unique flavour and odour, high bioactivity, and a distinctly different phytochemical profile than raw vegetables. In this mini review, we summarize data on changes in phytochemical content during lactic-acid fermentation of various cruciferous vegetables. The main focus was on the changes in the group of glucosinolates, polyphenols and carotenoids.

A comparative study on the quality attributes, phenolic content and antioxidant activity of cultivated and wild asparagus as influenced by seasonal variations

AbstractThe wild asparagus Asparagus acutifolius L. is common in the Mediterranean Basin. Wild asparagus spears are an important food source within their native range, and can be used as a sustainable nutrition source. In addition, interest has risen in wild relative species of Asparagus as a source of genetic improvement in Asparagus officinalis L. In this study, the quality traits (spear colour, total soluble solid content, dry matter content and chlorophyll and sugar fractions) and health-related compounds (total phenolics and antioxidant capacity) of fresh spears of wild and cultivated asparagus grown in Turkey were compared using the same three harvest periods for two consecutive years. The results of this study indicated that spears of wild asparagus contained a higher level of greenness (–a*), hue angle, total soluble solid, dry matter, chlorophyll, sugars, total phenolic content and antioxidant activity, compared to cultivated asparagus. Although there was no significant difference in the total soluble solid, glucose, sucrose and antioxidant activity in the contents of the spears of both species throughout the season, the colour, dry matter, chlorophyll, fructose, total sugar and total phenolic content were subject to seasonal variations. Colour, chlorophyll and total phenolic content showed some minor fluctuations over the course of the season, but the patterns of fructose and total sugar differed, which tended to increase throughout the harvest season. The present work suggests greater quality traits and biochemical compounds of the spears of A. acutifolius compared with those of commonly cultivated species.

Stability of vitamin C, carotenoids, phenols, and antioxidant capacity of pasteurised orange juice with resistant maltodextrin storage.

Resistant maltodextrin (RMD) was added at increasing concentrations (0%, 2.5%, 5% and 7.5%) before pasteurisation to orange juice to analyse its potential protective effect on the health-related bioactive compounds of pasteurised orange juice throughout its storage time. Samples were characterised in terms of basic physico-chemical properties and bioactive compounds at the beginning of the storage. Higher concentrations of RMD proved to better preserve the bioactive compounds of orange juice, thus obtaining a higher antioxidant capacity (AC). Stability of all samples was determined by measuring the same parameters at days 0, 15, 45, 75, 105, 136 and 170 of storage. °Brix and pH were very stable in all samples along storage, while all bioactive compouds had negative variations. However, RMD addition slightly improved ascorbic acid, vitamin C, total phenols, and total carotenoids retention, improving then its AC. This effect was greater in the 5% RMD-added samples. All bioactive compounds showed a positive Pearson's correlation coefficient with AC. Colour variations were also measured at days 105 and 170. All samples had a positive variation of all colour parameters, being this clearer at day 170. This work enlights the potential functionality of RMD to better preserve the health-related compounds of pasteurised orange juice.

Effect of drying treatments on the global metabolome and health-related compounds in tomatoes

Drying fruits and vegetables is a long-established preservation method, and for tomatoes, in most cases sun-drying is preferred. Semi-drying is relatively a new application aimed to preserve better the original tomato properties. We have assessed the effects of different drying methods on the phytochemical variation in tomato products using untargeted metabolomics and targeted analyses of key compounds. An LC-MS approach enabled the relative quantification of 890 mostly semi-polar secondary metabolites and GC–MS analysis in the relative quantification of 270 polar, mostly primary metabolites. Metabolite profiles of sun-dried and oven-dried samples were clearly distinct and temperature-dependent. Both treatments caused drastic changes in lycopene and vitamins with losses up to > 99% compared to freeze-dried controls. Semi-drying had less impact on these compounds. In vitro bioaccessibility analyses of total phenolic compounds and antioxidants in a gastrointestinal digestion protocol revealed the highest recovery rates in semi-dried fruits. Semi-drying is a better way of preserving tomato phytochemicals, based on both composition and bioaccessibility results.

Analysis of Apple Fruit (Malus × domestica Borkh.) Quality Attributes Obtained from Organic and Integrated Production Systems

The aim of this study was to compare total phenolic content (TPC), radical-scavenging activity (RSA), total anthocyanin content (TAC), sugar and polyphenolic profiles of two apple cultivars (‘Discovery’ and ‘Red Aroma Orelind’) from organic and integrated production systems in climatic conditions of Western Norway. Sixteen sugars and four sugar alcohols and 19 polyphenols were found in the peel, but less polyphenols were detected in the pulp. The peel of both apples and in both production systems had significantly higher TPC and RSA than the pulp. The peel from integrated apples had higher TPC than the peel from organic apples, while organic apples had higher TAC than the integrated. Sucrose and glucose levels were higher in organic apples; fructose was cultivar dependent while minor sugars were higher in integrated fruits. The most abundant polyphenolic compound in the peel of the tested cultivars was quercetin 3-O-galactoside, while chlorogenic acid was most abundant in the pulp. Regarding polyphenols, phloretin, phloridzin, protocatechuic acid, baicalein and naringenin were higher in organic apple, while quercetin 3-O-galactoside, kaempferol 3-O-glucoside, chlorogenic acid and syringic acid was higher in integrated fruits. In conclusion, organic ‘Discovery’ and integrated ‘Red Aroma Orelind’ had higher bioavailability of health related compounds from the peel and the pulp.

High-quality Chlorella vulgaris biomass harvesting through chitosan and polyacrylamid2e.

Microalgal biomass is an emerging source of renewable energy and health-related compounds. However, harvesting of microalgae is a techno-economic hinder. In this research, chitosan and polyacrylamide were optimized harvesting condition for Chlorella vulgaris. Stirring at 300rpm for 2min is optimum for chitosan and polyacrylamide. Low-dose (10mg/L) chitosan (flocculation efficiency (FE), 98.10 ± 1.06%) is more efficient than high-dose (25mg/L) polyacrylamide (FE 94.57 ± 0.55%) for harvesting C. vulgaris. Chitosan resulted flocs settled more quickly than polyacrylamide, while polyacrylamide keep > 90% FE in a wider pH range (7-10) than chitosan (7-8). Chitosan and polyacrylamide both have no negative effect on biomass composition, including protein, carbohydrate, and carotenoid. C. vulgaris in flocs could successfully regrow in fresh culture media. The residual culture media was recycled with little impact on cell growth. All the results suggested that chitosan and polyacrylamide could harvest high-quality microalgal biomass.