Abstract:Food industry is a main pillar industry of national economy. Healthy food is an inseparable part of the modern food, which is the greatest boost power of the upgrading and development of food industry. The production and development of healthy food has always been the direction of the food industry. Through the modern production mode of internal search and external strengthening of health factors, screening and development of sustainable nutritional and healthy raw materials, the implementation of the “Healthy China 2030” planning outline was promoted under the new development pattern and the socialist conservation-oriented country building was assisted. The basic situation of the development of health food and food industry in China was summarized, and the current situation of healthy food industry and the problems that need to be solved in the transformation and development of the food industry were analyzed. It was proposed that the development direction of the food industry was the dual orientation of flavor and health, and there should be dual vision of modernization and internationalization for food industry. It was emphasized that the development of food industry should follow the principle of “healthy raw material mining-technological and theoretical innovation-intelligent and scientific supervision”, and the big food concept and diversified food supply system should be established. It was hoped to provide a scientific and technological theory guidance for the sustainable development of food industry.

Abstract:Peptides were compounds with intermediate molecular structures between amino acids and proteins, having numerous nutritional properties including easy absorption, low osmotic pressure, low immunogenicity, and high tissue permeability. They were also important chemical messengers for tissue and cells capable of regulating cellular metabolism. Food-derived peptides were an important nutritional bases prepared from food protein using either a restriction enzymatic hydrolysis or biological fermentation, possessing both good nutritional value and exerting various physiological modulatory activities. However, the transport and absorption of food-derived functional peptides, as well as the spatial and temporal dynamic distribution in intracellular subcellular organelles and its functional effect on the regulation of nutrient metabolism, have yet to be studied. Moreover, the mode of action of the synergy between different structural and functional peptide molecules (such as transmembrane peptides, signal peptides, transport peptides, etc.) remained unclear, thereby restricting the basic research and rapid industrial development of food-derived peptides. Herein, the multi-dimensional peptide function evaluation methods in chemical, in vitro biological, lower/higher model animals, and clinical dimensions as well as the molecular structure-activity relationships of food-derived peptides were systematically introduced. The molecular conformational rules of food-derived peptides were described from the “top-down” and “bottom-up” approaches, and a “structure-effect” characterization theory based on molecular hybridization orbitals had been developed. Furthermore, the structure-activity relationship of peptide molecules with different molecular and structural features (such as primary amino acid sequence, spatial configuration, arrangement of the peptide bonds in the main chain, diversity of side chain functional groups, and α-carbon chirality, among others, etc.) in the process of transport and absorption had also been reviewed. The regulative law of body metabolism by food-derived peptides in complex systems of nutrition research field and the scientific underpinnings of peptide absorption and metabolism, and its ramifications for regulating precision nutrition, have also been examined. The functional properties of food-derived peptides, the “structure-activity” relationship, and the absorption and metabolism mechanism were all described in detail in order to provide some scientific guidance and reference for the future research on food-derived peptides.

Abstract:China is the most important country for edible mushroom production, and the total yield of edible mushroom in China ranks first in the world. Peptides are one of the important bioactive components and typical taste compounds in edible mushroom, but the mechanism underlying the functional activity and flavor formation of edible mushroom peptides are still unclear at present. Meanwhile, the lack of standardized and industrialized production and processing technologies seriously restricts the rapid and healthy development of the edible mushroom peptides industry. The peptides preparation from different edible mushroom materials such as edible mushroom fruiting body, mycelium, and by-products from mushroom production or processing were expounded, and many advantages such as short cycle, low cost, and easy regulation for the preparation of edible mushroom peptides using biological fermentation method were revealed, which would develop to be an important approach for the exploitation of edible mushroom peptides products. However, it was complex and difficult to be industrialized for pure edible mushroom peptides separation and purification using gel chromatography and reverse phase high performance liquid chromatography (RP-HPLC). At present, the health function researches of the edible mushroom peptides mostly focused on the antihypertensive effect by inhibiting angiotensin-converting enzyme (ACE) activity. Although the researches on the activities of antioxidation, anti-inflammatory, immune regulation and neuroprotection of edible mushroom peptides had been involved, these researches were not systematic and deep enough. The health function of edible mushroom peptides needs to be further explored. Because of the weak flavor, edible mushroom peptides were mainly used together with traditional monosodium glutamate, nucleotides and amino acids. Typical flavor peptides from edible mushroom needs to be fully exploited, and the preparation of edible mushroom flavor peptides with high efficiency, low cost and strong flavor will be an important breakthrough to improve the utilization of edible mushroom peptides. At the same time, edible mushroom peptides with some functional characteristics such as preservation, antibacterial and antiviral effects, and toxic effects were proved. It will become the most promising research field for edible mushroom peptides to establish the information database of peptides characteristics from different raw materials, construct the engineering bacteria with high efficiency of peptide biotransformation, establish the edible mushroom cells factory qualified with specific functional peptides, and realize the industrialization upgrading of the green biomanufacturing key technology of edible mushroom peptides.

Abstract:Aiming at the risk of hyperlipidemia, hypertension, hyperglycemia and other diseases caused by high fat intake, it was considered to be an effective way to achieve healthy diet without reducing sensory quality by directional design of food emulsion structure and regulating the interaction between food and gastrointestinal fluid to delay the lipid digestion. The physicochemical properties (particle size distribution, thermodynamic properties, rheological properties, etc.) of whey protein micro-gel particle (WPMP) prepared from whey protein concentrate (WPC) by combined heat-shearing treatment under different pH were investigated. The stability of emulsions added with WPMP in the digestive tract and the release rate of free fatty acid (FFA) were measured. The results showed that WPMP prepared at pH 5.5 had the relatively small median particle size of 6.63μm, the highest thermal stability, the lowest fluid index (n=0.06) and the better thixotropy (SR=0.42). The oil droplet size of the emulsion stabilized by WPMP was significantly smaller than that of the emulsion stabilized by WPC (P<0.05). And the minimum oil droplet size of emulsion stabilized obtained at addition of the WPMP prepared at pH 5.5 was 13.28μm. Compared with emulsion stabilized by WPC, WPMP stabilized emulsions had higher stability and lower FFA release rate in simulated gastrointestinal digestive juice. Emulsions stabilized by WPMP prepared under different pH had different FFA release rates. The study confirmed that WPMP had a certain barrier effect on the bile salt interface replacement and lipase-colipase interface adsorption in the digestive tract. Therefore, WPMP had a certain inhibitory effect on the lipid digestion and lipid absorption of emulsions. And it was regulated by the interfacial structure of WPMP. It was hoped that the research results could provide a reference for the directional design of emulsion structure to inhibit lipid digestion.

Abstract:The casein-pectin conjugate was prepared by Maillard reaction, and the effects of pectin on the structural and functional properties of casein was investigated. The optimum process for casein-pectin conjugate was determined by combining response surfaces with single factors taking the grafting degree and browning index as the response values. Flaxseed oil microencapsulation was prepared using casein-pectin conjugate as wall materials. The results showed the optimum process conditions were casein-pectin mass ratio 3∶1, heating time 1.5h, and heating temperature 90℃. The grafting degree of casein-pectin conjugate were 37.06%±0.80% and the browning index was 1.05±0.014. The determination results of secondary structure showed that the α-helixes, β-sheets, and β-turns contents of casein-pectin conjugate was decreased by 26.39%, 9.21%, and 2.23%, respectively, while the random curl content was increased by 12.43%, compared with casein. The functional properties (solubility, emulsification, thermal stability and antioxidant activity) of casein-pectin conjugate were significantly improved compared with casein. Flaxseed oil microencapsulation was prepared by spray drying using casein-pectin conjugate as the wall material and flaxseed oil as the core material. The results showed that the maximum encapsulation efficiency (77.06%±0.98%) was reached at mass ratio of 1∶1 between casein-pectin conjugate and flaxseed oil, and the microencapsulation had a complete spherical structure without fragmentation. In addition, the peroxidation value of free flaxseed oil was (14.70±0.51) meq/kg after stored at 25℃ for 28d, the peroxidation value microencapsulated flaxseed oil was only (3.82±0.07) meq/kg, indicating that the antioxidant activity of flaxseed oil was significantly improved by casein-pectin conjugate. This study aimed to provide a scientific basis for the application of casein in food industry.

Abstract:Lactoglobulin, one of major allergens in cow milk, was studied in this paper, and the T cell immune tolerance hydrolysates of β-lactoglobulin were prepared and identified to provide a theoretical basis for oral immunotherapy for patients with cow milk allergy. Firstly, the bioinformatics method was used to predict the possible β-lactoglobulin T-cell epitopes, and then, β-lactoglobulin was respectively hydrolyzed by six kinds of protease. The amino acid sequences of polypeptide of β-lactoglobulin hydrolysates were analyzed by mass spectrometry,and these peptides were synthesized by solid phase synthesis. The immune tolerance of the peptides were identified by T cell proliferation test. Therefore, trypsin, protamex, papain and neutrase hydrolysates were initially screened for T cell immune tolerance. Furthermore, the immune tolerance of β-lactoglobulin hydrolysates were evaluated by animal experiments. The levels of specific antibody (IgE, IgG₁, IgG_2a), Th1 cytokine (IFN-γ, IL-17), Th2 cytokine (IL-4, IL-5, IL-13), histamine, chitinase-3-like protein 1 in mice serum and the differentiation of mice spleen cell subsets were measured in vivo. The results showed that trypsin, protamex and papain hydrolysates had oral tolerance, among which protamex and papain hydrolysates had been reported innovatively. Although neutrase protease hydrolysates contained T cell epitopes, they were still allergenic. Therefore, the hydrolysates containing T cell epitopes did not necessarily have oral immune tolerance and need to be verified in vivo. The conclusion of this study could provide an important theoretical basis for the development of new anti-allergy milk-based materials and clinical treatment of milk allergy.

Abstract:Ultra-high temperature treatment (UHT) is a common sterilization method for milk that can be classified as direct and indirect UHT. Direct UHT was not widely applied in the dairy industry due to the high cost. Recently, with higher requirements of nutrients and flavor of milk from consumers, direct UHT was re-concerned due to its high heating rate, short heating time, and low loss of flavor and nutrients. This study compared the effects of two direct UHT methods, steam infusion and steam injection on physio-chemical properties, native whey proteins content, and volatile compounds content of milk. The results showed that UHT milk treated by steam infusion had lower mean particle size, instability index, and viscosity, whereas higher levels of desaturated whey proteins, compared to that in UHT milk treated by steam injection. 59 volatile compounds in total were detected in UHT milk through two extraction methods as solid-phase microextraction arrow and solvent-assisted flavor evaporation combined with gas chromatography-mass spectrometry, of which 50 volatile compounds were detected in steam-injection-treated UHT milk and 52 volatile compounds were detected in steam-infusion-treated UHT milk. Steam-infusion-treated UHT milk had a lower proportion of ketones, aldehydes, and fatty acids, while a higher proportion of esters and alcohols compared to that in UHT milk treated with steam injection. Principal component analysis results showed that steam-injection-treated UHT milk and steam-infusion-treated UHT milk could be distinguished by volatile compounds, indicating that different direct UHT methods could influence the flavor of UHT milk. It was recommended that dairy companies select steam injection if they intend to produce UHT milk with a heavier milky flavor, while select steam infusion if they plan to produce UHT milk with less cooking flavor, less off-flavor, and higher physical stability during storage. The result of this study aimed to provide supporting data and theory reference for the dairy industry to choose proper sterilization methods and produce UHT milk with a longer shelf-life, higher levels of nutrients, and better flavor.

Abstract:Gastric ulcer is a peptic ulcer disease caused by gastric mucosal lesion. Because of its various side effects of chemotherapy drugs, it is very important to seek safer and more effective natural active compounds to treat gastric ulcer. Polysaccharides were extracted from small black soybean, cowpea, pea and chickpea by water extraction and alcohol precipitation. The basic nutritional composition, monosaccharide composition and molecular weight distribution were determined, and the protective effects and potential mechanism of four legume polysaccharides on ethanol-induced acute gastric mucosal lesion in mice were explored. The results showed that the sugar contents of polysaccharides from small black soybean, cowpea, pea and chickpea were 66.40%, 71.79%, 67.41% and 53.31%, respectively, and the molecular weight distribution was wide. The monosaccharide composition of cowpea, pea and chickpea polysaccharides were mainly arabinose, galactose and galacturonic acid, which belonged to pectin acidic polysaccharide, while the small black soybean polysaccharides were mainly composed of galactose and mannose, which belonged to neutral polysaccharide. The inhibition rates of small black soybean, cowpea and chickpea polysaccharides on gastric mucosal lesion were 37.1%, 34.4% and 29.8%, respectively, which could reduce the gastric mucosal lesion in mice. Cowpea polysaccharides could significantly inhibit the expression of interleukin-6 and tumor necrosis factor-α (P < 0.05). Small black soybean polysaccharides could significantly reduce the content of malondialdehyde in gastric tissue and increase the activity of total superoxide dismutase and the content of reduced glutathione (P < 0.05). Both two polysaccharides had better gastric mucosal protective effect. This study wished to provide a theoretical reference for the development of healthy food with gastric protection function by using legume polysaccharides.

Abstract:Carrageenan is a common food additive, but its effect on changing the structure of gut microbiota was questioned. In this study, the C57BL/6 mice were given three dosages of λ-carrageenan, including low, medium and high dose (1.7,8.3,41.7mg/kg) for 12 weeks. The effects of λ-carrageenan on glucose metabolism and gut microbiota in mice were investigated by glucose tolerance test, insulin tolerance test and gut microbiota 16S rDNA sequencing. And the role of gut microbiota in the effect of λ-carrageenan on glucose metabolism in mice was verified by fecal bacteria transplantation experiments. The results showed that intake of different dose λ-carrageenan could cause the symptoms of metabolic disorders in mice, such as decreased body weight gain, elevated fasting blood glucose and insulin resistance. By the analysis of gut microbiota composition, it was found that λ-carrageenan could significantly affect the abundance and structure of gut microbiota. At the phylum level, λ-carrageenan increased the relative abundance of the Firmicutes and reduced the relative abundance of Bacteroidota. At the genus level, the abundance of Bacteroidales_S24-7_group_norank was reduced, which regulated blood glucose. The abundance of Lactobacillus and Lachnospira related to lipid metabolism and weight loss was increased by λ-carrageenan administration. And it significantly increased abundance of Akkermansia, which is related to the degradation of the intestinal mucus layer. In addition, the results of fecal bacteria transplantation showed that the metabolic disorders appeared in fecal transplant mice were consistent with those of λ-carrageenan gavage mice. The results showed that intake of λ-carrageenan, especially high doses of λ-carrageenan, induced metabolic disorders in mice by interfering with the composition of the gut microbiota.

Abstract:Ampelopsis grossedentata leaf is rich in polyphenols, and now is regarded as a new food material with high value for utilization. Two typical kinds of calluses were induced from Ampelopsis grossedentata young leaves. The excellent calluses were successfully obtained by hormone optimization and successive screening, which were further used to develop the cell suspension culture system of Ampelopsis grossedentata leaf. The main polyphenols in the suspensively cultured cells were identified, and their antioxidant activities were evaluated in the meantime. Seven polyphenols were identified in the extracts of calluses by the UPLC-Q-TOF MS/MS and HLPC detection, while ten polyphenols were identified in the suspensively cultured cells. Three polyphenols including proanthocyanidin B1, (+)-catechin, epigetechin gallate were found both in calluses and cells with high concentration, among which epicatechin gallate was the most abundant compound, whose contents reached 5020.965μg/g and 1044.725μg/g in calluses and cells, respectively. In addition, total polyphenols extracts from the suspensively cultured cells displayed strong antioxidant activities, with IC 50values of 30 681 μg/mL and 3.685μg/mL respectively in the ABTS⁺ and DPPH free radical scavenging tests. What's more, both the DPPH radical scavenging and total reduction ability of the polyphenol extracts were significantly stronger than vitamin C under the same mass concentration, which were mainly attributed to epicatechin gallate and (+)-catechin. It was hoped that this study would provide a reference for the culture of Ampelopsis grossedentata leaf cells and the regulation of its polyphenolic secondary metabolite synthesis.

Abstract:There are a large number of incidental nanoparticles endowed with special activities and functions by their nano-scale structures in some traditional food systems, but the effects of the incidental nanoparticles on the human cells remain unclear. In the case study of freshwater clam soup and its incidental nanoparticles prepared by liquid chromatography, the cytotoxicity effects of freshwater clam soup and its nanoparticles on MDCK, Caco-2, L-02, and murine peritoneal macrophages were evaluated. Besides, the phagocytosis functions of murine peritoneal macrophages interacted with soup and its nanoparticles were also investigated. The results showed that freshwater clam soup and its incidental nanoparticles did not show apparent toxicity to the four cell within the concentration of 15.63-500.00μg/mL. Further study found that murine peritoneal macrophages could engulf freshwater clam soup incidental nanoparticles. They did not influence the membrane potential and phagocytosis function of the normal peritoneal macrophages but prevented the cells from the membrane hyperpolarization, mitochondrial oxidative stress, and phagocytosis suppression induced by AAPH-induced oxidative stress. The antioxidant analysis revealed that freshwater clam soup incidental nanoparticles exerted FRAP and ABTS antioxidant activity, but not ORAC antioxidant activity. The research results provided a scientific basis for further research on the physiological function and related mechanism of freshwater clam soup and its incidental nanoparticles.

Abstract:Outer membrane lipoprotein receptor LolB is a key factor for gram-negative bacteria to transport lipoprotein. Bioinformatics methods and real-time fluorescence quantitative PCR were used to investigate the physicochemical properties, structure and function of LolB in Shewanella putrefaciens from aquatic products and its gene expression changes under different environment. The results showed that lolB gene had high sequence conservation property and LolB was a stable hydrophilic protein with a molecular weight of about 23ku. LolB contained signal peptides and 21 phosphorylation sites, but had no transmembrane structure. The secondary structure of LolB was mainly random coil and β -folding, and the tertiary structure was β barrel-shaped. LolB was predicted to interact with a variety of proteins, including LolA of lipoprotein transport system, LolC and LolE family transmembrane proteins, ABC transport-related proteins, catalytic cracking glycotransferase involved in increasing cell membrane rigidity and maintaining cytoplasmic stability. Fluorescence quantitative PCR results showed that the expression of lolB gene was up-regulated when the bacteria were subjected to a certain degree of stravation, ethanol, osmotic pressure and high temperature stress, which presented a trend of up-regulation and then down-regulation with the increase of stress degree. At 4℃, lolB gene expression pattern was similar to that of the control group. Exogenous signal molecules C₆-HSL induced high expression of lolB and could interact with Leu51 residue of LolB protein through π-alkyls. It was hoped that the results could provided a preliminary analysis of the function of LolB in S. putrefaciens and offered a new idea for the targeted inhibition of S. putrefaciens in aquatic products.

Abstract:Lactic acid bacteria biofilm has various physical properties and physiological functions such as adhesion, resistance and antibacterial activity. It is widely used in improving the texture of food and in the biological preservation of food. The formation of lactic acid bacteria biofilm needs five stages as attachment, formation, maturation, aging off and reattachment, and is regulated by the quorum sensing system. Quorum sensing system (QS) is a widespread gene expression regulatory system in bacteria, which regulates the physiological functions of bacteria by targeting the expression of related genes through signaling molecules. The LuxS/AI-2 type QS is the main QS for regulating the probiotic properties of lactic acid bacteria. Understanding the LuxS/AI-2 type QS of lactic acid bacteria and its mechanism of regulating biofilm formation is crucial for further applications of lactic acid bacteria in the food industry. The recent research progress on the formation processes of lactic acid bacteria biofilms, and the five regulatory elements of LuxS/AI-2 type QS regulating lactic acid bacteria biofilm formation, including the signaling molecule AI-2 (autoinducer-2), key regulatory genes (luxS, tuf, fba, gap), key regulatory proteins (LuxS, LacI, AraC, PadR, and Rbs family proteins), the possible receptor proteins of signaling molecule AI-2 (LuxP, LsrB, RbsB and the dCACHE domains receptor proteins) and key metabolic pathways was highlighted. Furthermore, the possible molecular mechanisms of signal molecule AI-2 regulating biofilm formation of lactic acid bacteria, as well as the screening strategy of signal molecule AI-2 receptor protein were summarized. The aim of study was to provide a theoretical guide to gain insight into the LuxS/AI-2 type QS that regulates the biofilm formation of lactic acid bacteria.

Abstract:Focus on the problem of cadmium (Cd) enrichment in Boletus griseus, total Cd content in the B. griseus samples from three regions in Yunnan was investigated, and three B. griseus with different Cd contents (high, medium, and low) were selected to evaluated the bioaccessibility of Cd (Cd-BAc) in B. griseus by a more realizable and quantifiable in vitro whole biomimetic digestive method established in this study. The effects of five dietary nutrients, tannic acid, CaCl₂, proanthocyanins, Zn/Ca gluconate and rambutan peel polyphenols, on Cd-BAc were studied, and the edible health risk of Cd in B. griseus was assessed based on total Cd contents and Cd-BAc. The results showed that there were high Cd contents in 53 B. griseus samples. The Cd-BAc during the gastric digestion was 55.30%-59.36%. The Cd-BAc was decreased to 39.59%-52.86% due to significantly reduced dissolution in the weakly alkaline and nearly neutral environment of the small intestine. The Cd-BAc was further decreased to 21.41%-25.28% by large intestinal flora fermentation. The five dietary nutrients had little effects on Cd-BAc during the gastric digestion, but significantly reduced Cd-BAc during the small and large intestinal flora fermentation, of which CaCl₂ was the most effective. Based on the total Cd contents in B. griseus, the human Cd exposure risk hazard quotient (HQ) caused by medium Cd and high Cd content of B. griseus was 2.98 and 5.13, but considering Cd-BAc and the effects of five dietary nutrients, the HQ could be reduced to 0-0.37. The result indicated that the edible health risk of Cd in B. griseus was very high, and dietary nutrients could modulate its health risk to human by reducing its bioaccessibility in intestine. Therefore, dietary nutrients might be an effective strategy to control the health risks of Cd during the processing or consumption of foods with high Cd content. However, the effectiveness of this strategy requires further in vivo experimental verification.

Abstract:In order to explore the suitability of different varieties of lotus root for juice processing, ten representative lotus root varieties were selected as experimental materials, the physicochemical indexes and basic nutritional composition of lotus root raw materials were determined, and the processing quality, nutritional value and physical properties of the lotus root fresh juice were analyzed. The quality of lotus root fresh juice was comprehensively evaluated by combining principal component analysis and cluster analysis methods. The results showed that there were significant differences (P<0.05) in all quality indicators of the ten lotus root raw materials and their fresh juices, and the nine quality indicators of lotus root fresh juices was reduced to three factors by principal component analysis, with a cumulative contribution of 88.279%. Ten species of lotus roots were divided into four categories by cluster analysis, the first category being Elian No.5, Elian No.6 and Elian No.11, the second category being Lujiang floral lotus root, Xishui Bahe lotus root, Elian No.9, Hangzhou white lotus root and Xin 35, the third category being Wuzhi No.2, and the fourth category being Miancheng lotus root. Further correlation analysis of the quality indexes of lotus root fresh juice with the quality indexes of lotus root raw materials revealed that varieties with small brightness of lotus root, low starch content and high juice yield were more suitable for juice processing. Therefore, Hangzhou white lotus root, Xishui Bahe lotus root, Elian No.9 and Lujiang floral lotus root were more suitable as special varieties for juice processing.

Abstract:Freeze drying can better retain nutritional and functional substances in blueberries such as anthocyanins and vitamins. However, it is difficult for internal water to diffuse outward through the dense waxy layer of the blueberry epidermis during the freeze drying process, which triggers structural collapse as well as a series of serious quality defects of products, including epidermis shrink, hollowness, and juice loss. These limited the application of the freeze drying technology in the field of blueberry drying. To improve the quality of freeze-dried blueberries, the influence of pretreatment with soaking in Na₂CO₃ solution (3,10, 30min), peeling (top, bottom, top and bottom), punching (12,14, 36 holes), and cutting epidermis (2,8, 16 incisions) on the drying characteristics, hygroscopicity, and sensory qualities such as texture, color and aroma of freeze-dried blueberry were investigated. The results indicated that compared with non-pretreated freeze-dried blueberries, both punching and cutting epidermis treatment could effectively avoid the collapse and shrink of freeze-dried blueberries, which obtained better quality than the treatment of soaking in Na₂CO₃ solution and peeling. Among them, the freeze-dried blueberries with punching (36 holes) and cutting epidermis (16 incisions) remained their intact appearance and microstructure with reduced drying time by 6 h and 4 h, respectively. Meanwhile, the brittleness was increased by 31.55% and 4.06%, respectively. There was no obvious shrink and collapse of epidermis and interior structure in these two processed blueberries, and the color and aroma were closer to the fresh blueberries than that of other treatments. This study aimed to provide a guiding reference for the preparation of high-quality whole blueberry fruits by freeze drying.