Determination of Carbohydrate Composition in Mealworm (Tenebrio molitor L.) Larvae and Characterization of Mealworm Chitin and Chitosan.

Mealworm (Tenebrio molitor L.) is a classic edible insect with high nutritional value for substituting meats from vertebrates. While interest in mealworms has increased, the determination of carbohydrate constituents of mealworms has been overlooked. Thus, the aim of the present study was to investigate the carbohydrate content and composition of mealworms. In addition, the characteristics of mealworm chitin were determined as these were the major components of mealworm carbohydrate. The crude carbohydrate content of mealworms was 11.5%, but the total soluble sugar content was only 30% of the total carbohydrate content, and fructose was identified as the most abundant free sugar in mealworms. Chitin derivatives were the key components of mealworm carbohydrate with a yield of 4.7%. In the scanning electron microscopy images, a lamellar structure with α-chitin configuration was observed, and mealworm chitosan showed multiple pores on its surface. The overall physical characteristics of mealworm chitin and chitosan were similar to those of the commercial products derived from crustaceans. However, mealworm chitin showed a significantly softer texture than crustacean chitin with superior anti-inflammatory effects. Hence, mealworm chitin and chitosan could be employed as novel resources with unique advantages in industries.

Could Defatted Mealworm (Tenebrio molitor) and Mealworm Oil Be Used as Food Ingredients?

Before edible insects may be used as an alternative food, it is necessary to develop basic product forms and evaluate their characteristics. We made two basic commercial products (defatted powder and oil) from mealworm, a popular edible insect. The defatted mealworm powder possessed a sufficient amount of protein, and it had a savory taste due to plentiful free amino acids. Additionally, it had abundant minor nutrients and bioactive compounds. The physicochemical properties of mealworm oil were very similar to vegetable oil, and mealworm oil was also abundant in bioactive nutrients, especially γ-tocopherol. In addition, the predicted shelf life of mealworm oil was suitable for commercial use. Moreover, mealworm had high antioxidant and anti-inflammation activities, which may arise from functional peptides and glucosamine derivatives such as chitin and chitosan. In short, the defatted mealworm powder and mealworm oil could be successfully used as novel food ingredients.

Physicochemical properties and oxidative stabilities of mealworm (Tenebrio molitor) oils under different roasting conditions.

Physicochemical properties and oxidative stabilities of mealworm (Tenebrio molitor) oils under different roasting conditions were investigated. Oils were extracted using n-hexane from mealworms roasted at 200°C for 0, 5, 10, and 15 min and physicochemical properties and oxidative stabilities of oils were analyzed. Roasting increased the color intensity and the oleic acid and δ-tocopherol contents, but decreased linoleic acid, and α- and γ-tocopherol contents. An improvement in oxidative stability was observed in roasted mealworm oils, demonstrated by induction time and peroxide values. Mealworm oil contained abundant essential fatty acids and exhibited a superior oxidative stability.

The cariogenicity of hydrolyzed starch foods by measuring the polyacrylamide hydroxyapatite (PAHA) disc.

OBJECTIVES: This study measured the degree of demineralization of starch foods affected by hydrolyzed starch in total starch using the polyacrylamide hydroxyapatite (PAHA) disc. DESIGN: A total of 10 ml of test food was added to a PAHA disc and 5 ml artificial saliva, followed by inoculation with 1 µl of S. mutans and incubation at 37 °C for 180 min. The demineralization effects were then determined using CLSM. RESULTS: The proportion of hydrolyzed starch in total starch in potato increased over time, while hydrolyzed starch in other test food decreased. When the amount of hydrolyzed starch in total starch increased after 180 min (p=0.000), the surface roughness of the PAHA disc in potato was significantly decreased. Wheat-based sugary snacks, such as chips and cookie, had relatively high cariogenic potentials, whereas baked potato had a relatively low cariogenic potential. CONCLUSIONS: Hydrolyzed starch in total starch increased over time, and cariogenic potential was notably decreased. Measurement of PAHA disc may be a valid method for assessing the cariogenic potential of hydrolyzed starch foods.

Development of Safe Food Handling Guidelines for Korean Consumers.

The purpose of this study was to develop guidelines for Korean consumers with regard to safe food handling practices at home by identifying current food handling issues. Korean consumers' behaviors regarding their safe food handling were identified via survey questionnaires that included items on individual hygiene practices, prepreparation steps when cooking, the cooking process, and the storage of leftover foods. The subjects were 417 Korean parents with elementary school children living in Seoul and Gyeonggi Province in the central area of Korea. The survey results revealed gaps between the knowledge or practices of Korean consumers and scientific evidence pertaining to safe food handling practices. Based on these findings, a leaflet on safe food handling guidelines was developed in accordance with Korean food culture. These guidelines suggest personal hygiene practices as well as fundamental principles and procedures for safe food handling from the stage of food purchase to that of keeping leftover dishes. A pilot application study with 50 consumers revealed that the guidelines effectively improved Korean consumers' safe food handling practices, suggesting that they can serve as practical educational material suitable for Korean consumers.

Comparison of different gum-based thickeners using a viscometer and line spread test: a preliminary study.

OBJECTIVE: To compare fluid thickeners composed of starch polysaccharide (STA), guar gum-based polysaccharide (GUA), and xanthan gum-based polysaccharide (XAN) with the use of a viscometer and a line spread test (LST) under various measurement conditions. METHODS: The viscosity of thickened fluid with various concentrations (range, GUA 1%-4%, XAN 1%-6%, STA 1%-7%, at intervals of 1%) was measured with a rotational viscometer with various shear rates (1.29 s(-1), 5.16 s(-1), 51.6 s(-1), and 103 s(-1)) at a temperature of 35℃, representing body temperature. The viscosity of STA showed time dependent alteration. So STA was excluded. Viscosities of GUA and XAN (range of concentration, GUA 1%-3%, XAN 1%-6%, at intervals of 1%) were measured at a room temperature of 20℃. LST was conducted to compare GUA and XAN (concentration, 1.5%, 2.0%, and 3.0%) at temperatures of 20℃ and 35℃. RESULTS: The viscosities of 1% GUA and XAN were similar. However, viscosity differences between GUA and XAN were gradually larger as concentration increased. The shear thinning effect, the inverse relationship between the viscosity and the shear rate, was more predominant in XAN than in GUA. The results of LST were not substantially different from GUA and XAN, in spite of the difference in viscosity. However manufacturers' instructions do not demonstrate the rheological properties of thickeners. CONCLUSION: The viscosities of thickened fluid were different when the measurement conditions changed. Any single measurement might not be sufficient to determine comparable viscosity with different thickeners. Clinical decision for the use of a specific thickener seems to necessitate cautious consideration of results from a viscometer, LST, and an expert's opinion.

Measurement of the cariogenicity of snacks using a radioisotope PAHA disc.

OBJECTIVES: This study aimed to establish a method for measuring the cariogenic potential of foods with high reproducibility in vitro. METHODS: Streptococcus mutans (S. mutans) was incubated in test foods with radioisotope polyacrylamide hydroxyapatite (PAHA) for 150 min at 37 °C. Then, the amount of radioisotope (32)P released from PAHA was measured using a liquid scintillation counter and scanning electron microscopy (SEM). RESULTS: The radioisotope PAHA discs that were soaked in 10% sucrose solutions had a high cariogenic potential and showed a remarkably demineralized surface (p < 0.05). The radioisotope PAHA disc that was incubated with snacks that had a high cariogenic potential showed a remarkably demineralized surface via SEM. Candy had a relatively high cariogenic potential, whereas xylitol gum had a relatively low potential. CONCLUSIONS: The cariogenicity of snacks can easily be evaluated by measuring the amount of (32)P released from radioisotope PAHA discs.

Dietary Aloe Reduces Adipogenesis via the Activation of AMPK and Suppresses Obesity-related Inflammation in Obese Mice.

BACKGROUND: Metabolic disorders, including type II diabetes and obesity, present major health risks in industrialized countries. AMP-activated protein kinase (AMPK) has become the focus of a great deal of attention as a novel therapeutic target for the treatment of metabolic syndromes. In this study, we evaluated whether dietary aloe could reduce obesity-induced inflammation and adipogenesis. METHODS: Male C57BL/6 obese mice fed a high-fat diet for 54 days received a supplement of aloe formula (PAG, ALS, Aloe QDM, and Aloe QDM complex) or pioglitazone (PGZ) and were compared with unsupplemented controls (high-fat diet; HFD) or mice fed a regular diet (RD). RT-PCR and western blot analysis were used to quantify the expression of obesity-induced inflammation. RESULTS: Aloe QDM complex down-regulated fat size through suppressed expression of scavenger receptors on adipose tissue macrophages (ATMs) compared with HFD. Both white adipose tissue (WATs) and muscle exhibited increased AMPK activation through aloe supplementation, and in particular, the Aloe QDM complex. Obesity-induced inflammatory cytokines (IL-1ß and -6) and HIF1α mRNA and protein were decreased markedly, as was macrophage infiltration by the Aloe QDM complex. Further, the Aloe QDM complex decreased the translocation of NF-κB p65 from the cytosol in the WAT. CONCLUSION: Dietary aloe formula reduced obesity-induced inflammatory responses by activation of AMPK in muscle and suppression of proinflammatory cytokines in the WAT. Additionally, the expression of scavenger receptors in the ATM and activation of AMPK in WAT led to reduction in the percent of body fat. Thus, we suggest that the effect of the Aloe QDM complex in the WAT and muscle are related to activation of AMPK and its use as a nutritional intervention against T2D and obesity-related inflammation.

Comparative flavonoids contents of selected herbs and associations of their radical scavenging activity with antiproliferative actions in V79-4 cells.

To elucidate the health benefit of herbal teas on the cytotoxicity induced by H(2)O(2) in V79-4 cells, herbal extracts and its flavonoids were tested using lactate dehydrogenase release and determining intracellular reactive oxygen species generation and antioxidant activity with superoxide radical scavenging assay. Significant decrease in cell viability was observed on V79-4 cells treated with H(2)O(2) (1 mM), while herbal extracts and its flavonoids including catechin and epigallocatechin gallate prevented the LDH release from H(2)O(2) cytotoxicity. Total catechin contents of green tea (65.6 mg/g of dry matter) were significantly higher than other herbal teas (35.8 to 1.2 mg/g of DM). The relative concentration of the 4 major tea catechins ranked EGCG > EGC > EC > C. Green tea exhibited the lowest IC(50) values (2 g fresh herb/100 mL) of superoxide radical scavenging activity among the tested herbal tea, which indicates powerful antioxidant activity in O(2)(*-) radicals scavenging, followed by black tea, dandelion, hawthorn, rose hip, chamomile.

Impacts of sensory attributes and emotional responses on the hedonic ratings of odors in dairy products.

Consumers often decide to purchase certain items as a result of prompt emotional responses evoked by the products; therefore, it is important to investigate the emotional responses stimulated by food samples, as well as the sensory attributes of the products. The aim of this study was to examine influences of sensory attribute and emotional response on olfactory hedonic ratings of dairy products. Additionally, we compared this effect between women and men subjects. Sensory attributes of six natural odors produced by commercial dairy products were evaluated by 9 trained panelists. In addition, 100 untrained panelists (50 women and 50 men) rated the emotional response stimulated by the 6 odors using 25 paired semantic differential scales and the hedonicity using a 9 cm line scale, respectively. Untrained panelists more liked "sweet aromatics," "sour aromatics," "fermented aromatics," and "rich aromatics" over the other sensory attributes of dairy products. The olfactory hedonic ratings were increased when the odor was more characterized as "fragrant," "attractive," "comfortable," "familiar," "faint," "natural," or "modern." Specific sensory attributes were found to be related to specific adjective pairs representing the emotional response. Moreover, the ratings of adjective pairs representing emotional response of odors and their influences on hedonic ratings differed significantly between sexes. In conclusion, our findings suggest that the emotional responses as well as the sensory attributes affect the hedonic ratings of odors in dairy products.

Soy isoflavones as safe functional ingredients.

In recent years, isoflavones have increased in popularity as an alternative to estrogen therapy, particularly after the Women's Health Initiative demonstrated an increased risk of breast cancer, stroke, and heart attacks in response to estrogen and progesterone intervention. Isoflavones are heterocyclic phenols with structural similarity to estradiol-17beta and selective estrogen receptor modulators. Actions at the cellular level depend on the target tissue, receptor status of the tissue, and the level of endogenous estrogen. Clinical studies of soy-based diets evaluating the relation between soy consumption and serum lipid concentrations revealed that soy consumption significantly decreased total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels. Epidemiological studies suggest a protective effect of soy protein on breast tissue as evidenced by the lower rates of breast cancer in East Asian countries where soy is a predominant part of the diet. Soy products also alleviate menopausal symptoms by reducing hot flashes. However, whether these biological effects of soy products originated from isoflavones is not clear. Furthermore, data available from human studies on the effect of isoflavones on osteoporosis are limited, and additional studies are needed to support a role in osteoporosis prevention. To date, no adverse effects of short- or long-term use of soy proteins are known in humans, and the only adverse effects known are those reported in animals. In conclusion, isoflavones are biologically active compounds, and current data are insufficient to draw definitive conclusions regarding the use of isoflavones as an alternative to estrogen for hormone replacement in postmenopausal women. Large, long-term intervention studies examining adverse effects and disease outcomes are needed before definitive conclusion can be drawn.

Comparison of the physicochemical properties and ultrastructure of japonica and indica rice grains.

The physicochemical properties and ultrastructures of japonica vs indica rice varieties and waxy vs nonwaxy rice varieties were compared. The viscogram values of the indica varieties were significantly higher than those of the japonica varieties. The gelatinization temperatures, breakdown, and setback were significantly lower for waxy than for nonwaxy rice varieties. Japonica rice exhibited lower hardness but higher adhesiveness than indica rice. The air space between individual starch granules was larger for waxy than for nonwaxy rice. The starch granules were compact in japonica rice, while the compound starch granules of indica rice were much smaller than those of japonica rice and were scattered widely in the endosperm. The protein bodies in japonica rice were concentrated near the cell wall, whereas those in indica rice were scattered around amyloplasts. These results suggest that the ultrastructure of rice affects the texture of the cooked product.

Ultrastructure of individual and compound starch granules in isolation preparation from a high-quality, low-amylose rice, ilpumbyeo, and its mutant, G2, a high-dietary fiber, high-amylose rice.

The ultrastructures of isolated starch granules from Ilpumbyeo (IP), a low-amylose japonica rice, and its mutant, Goami2 (G2), a high-amylose rice, which have extreme contrasts in physicochemical properties, cooking qualities (Kang, H. J.; Hwang, I. K.; Kim, K. S.; Choi, H. C. Comparative structure and physicochemical properties of Ilpumbyeo, a high-quality japonica rice, and its mutant, Suweon 464. J. Agric. Food Chem. 2003, 51, 6598-6603. Kim, K. S.; Kang, H. J.; Hwang, I. K.; Hwang, H. G.; Kim, T. Y.; Choi, H. C. Comparative ultrastructure of Ilpumbyeo, a high-quality japonica rice, and its mutant, Suweon 464: Scanning and transmission electron microscopy studies. J. Agric. Food Chem. 2004, 52, 3876-3883), and susceptibility to amylolytic enzymes (Kim, K. S.; Kang, H. J.; Hwang, I. K.; Hwang, H. G.; Kim, T. Y.; Choi, H. C. Fibrillar microfilaments associated with a high-amylose rice, Goami2, a mutant of Ilpumbyeo, a high-quality japonica rice. J. Agric. Food Chem. 2005, 53, 2600-2608), were compared. In isolated preparation, IP consisted entirely of well-separated individual starch granules (ISG), whereas G2 consisted of two populations, the large voluminous bodies and the smaller forms, the ISGs. High-voltage electron microscopy revealed that each of the voluminous bodies consisted of tightly packed smaller subunits, the ISGs, indicating that they represent the compound starch granules (CSGs) of G2. This suggests that the structural as well as functional unit of G2 involved in food processing is, unlike IP and other ordinary rices, not ISG but is primarily CSG. ISGs located at the periphery of CSGs were fused to each other with adjacent ones forming a thick band or wall encircling the entire circumference. The periphery of ISGs separated from CSGs of G2 consisted of thin radially oriented filaments arranged side by side along the entire granule surface, whereas no such filaments occurred in ISG of IP. It appears that the thick band and the peripheral filaments surrounding CSGs and ISGs, respectively, function as a structural barrier that limits the entrance of water into the granules and subsequent absorption, causing the low swelling power, incomplete gelatinization, and finally poor quality of cooked rice in G2.

Fibrillar microfilaments associated with a high-amylose rice, goami 2, a mutant of ilpumbyeo, a high-quality japonica rice.

The ultrastructure of cooked and malt-treated cooked rice of Ilpumbyeo (IP) and its mutant Goami 2 (G2), which have extreme contrasts in physicochemical properties, cooking quality, and ultrastructural characteristics in raw grains (1, 2), was compared. In cooked rice of IP, starch granules in endosperm cells were evenly coalesced, appearing as homogeneously smooth sheetlike matrix and/or globules, whereas those in G2 were a heterogeneously coarse matrix in which a novel structural feature, the microfilaments, was embedded. In malt-treated cooked rice of IP, most starch was hydrolyzed by the malt enzymes, appearing as empty vacuoles surrounded by the cell wall, whereas that in G2 was highly resistant to malt treatment, remaining as distinct structural features, the malt-resistant compound starch granules. The property of G2's compound starch granules, which are tolerant of mechanical and chemical treatments thereby retaining their structural integrity (2) and of cooking and malt treatment thereby retaining their physical hardness, appears to play a major role in determining the quality of cooked rice of G2.

Comparative ultrastructure of Ilpumbyeo, a high-quality japonica rice, and its mutant, Suweon 464: scanning and transmission electron microscopy studies.

A new rice mutant Suweon 464 (S-464), which has extreme contrast in cooking quality and physicochemical properties from those of its mother variety Ilpumbyeo (IP), revealed striking differences in ultrastructure in in situ, fractured whole grain, and isolated starch preparation. In scanning electron microscopy (SEM), compound starch granules (CSG) in whole grains of IP were readily split during fracturing, whereas those in S-464 were structurally intact and were enclosed within a sac-like structure tolerant of fracturing. In isolated preparation, IP starch consisted entirely of individual starch granules, whereas S-464 starch consisted of mostly large CSG enclosed within the sac, preventing the release of the individuals. In transmission electron microscopy (TEM), S-464 starch granules were smaller, solidly "condensed", and highly contrasted, whereas those of IP were larger, loosely "diffused", and less contrasted. The boundaries of amyloplasts and starch granules in S-464 were coated with a thin proteinaceous layer, presumed to be the counterpart of the sac that enclosed the CSG observed in SEM.

Categorization of dysphagia diets with the line spread test.

OBJECTIVE: To categorize dysphagic diets according to the food's viscosity, as determined by an objective method. DESIGN: Description of dysphagic diet in terms of viscosity. SETTING: Food science laboratory at a university hospital. SPECIMENS: Twenty kinds of foods: 10 commercially available and 10 formulated for a dysphagic diet in a tertiary university hospital, representing a wide range of food viscosities. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Viscosity, measured with a viscometer, and a line spread test (LST). RESULTS: Logarithmic viscosity (centiPoise [cP]) values measured using a viscometer were inversely correlated with the extent of spread (centimeters) on an LST. (Pearson r=-.95, P=.0001). Viscosities and the LST results were 0.9+/-0.1cP and 5.5+/-0.5cm for water, 63.1+/-4.8cP and 3.4+/-0.1cm for the barium solution, 671.0+/-76.9cP and 2.4+/-0.1cm for yogurt, and 10,031+/-728cP and 1cm for pudding. CONCLUSIONS: Dysphagic diets can be categorized according to their viscosities by objective measurements. The LST correlated well with viscometer measurement and is a practical method with which to measure viscosity.

Comparative structure and physicochemical properties of Ilpumbyeo, a high-quality japonica rice, and its mutant, Suweon 464.

A new rice mutant Suweon 464 (S-464) derived from a high-quality rice, Ilpumbyeo (IP), revealed a striking difference in cooking quality from IP. The physicochemical properties of S-464 and IP were compared. S-464 was unusually high in amylose and fiber contents, had B-type crystallinity of starch, and had a markedly lower proportion of short chains in the distribution of glucan-chain fractions of debranched starch as compared with IP. Scanning electron microscopy revealed that starch granules of S-464 were much smaller in size than those of IP and that many of them were not separated from amyloplasts. The physicochemical properties of S-464 would contribute to poor gelatinization, lower swelling power, higher hardness, and less stickiness when cooked. Although S-464 may not be desirable for cooked rice, the mutant could be an excellent candidate for other processed food products on the basis of its unusual properties of starch and high fiber, protein, and lipid contents.