Quality components of sea buckthorn (Hippophae rhamnoides) varieties

The sensory quality and chemical constituents of juices from seven sea buckthorn (Hippophaerhamnoides L.) varieties were studied in two consecutive seasons. The juices were generally described as sour and astringent, with low sweetness and fruity flavor. The differences in sensory quality as well as in chemical composition between samples and years were significant (p < 0.05) in most parameters studied. The Chuiskaya variety was described as the sweetest, with the strongest fruity flavor, whereas the varieties Avgustinka, Botanicheskaya, Trofimovskaya, and Raisa were the sourest and most astringent. Total sugar (fructose and glucose) varied from 1.9 to 7.1 g/100 mL in juice, total acid (malic and quinic acids) from 3.1 to 5.1 g/100 mL, vitamin C from 29 to 176 mg/100 mL, and pulp oil from 0.7 to 3.6%. The soluble solids were between 7.4 and 12.6, the pH between 2.7 and 2.9, and the titrable acidity between 2.0 and 3.7. The redness was highest on Avgustinka and Raisa, but there were no differences in yellowness. Total sugar and the sugar/acid ratio correlated positively with sweetness and negatively with sourness and astringency, whereas total acid and titrable acidity correlated positively with sourness and astringency and negatively with sweetness.     

高压/酶解/闪式高速提取对金华火腿骨呈味物质的影响

以金华火腿骨为研究对象,研究不同提取方法对其呈味物质释放的影响。通过感官评价及可溶性糖、有机酸、5′-核苷酸和游离氨基酸的测定分析不同处理组间样品的差异,同时采用偏最小二乘回归法（partial least squares regression,PLSR）对提取物感官和呈味物质间进行相关性分析。感官评价发现,高压蒸煮的样品的鲜味、咸味和可接受度最高,其协同滋味的综合评分最佳;呈味物质分析发现,原液中所有呈味物质含量都最低,高压-复配酶解处理的样品中可溶性糖总量最高,高达132.68 mg/100 g;经过酶解处理样品有机酸含量显著增加（P<0.05）,达到3 733.32 mg/100 g;样品经不同处理后,5′-核苷酸含量呈现显著性增加（P<0.05）,总含量最高的是经过高压蒸煮处理的样品,质量分数高达1.24 mg/100 g,是原液和其他处理组样品的2.38～12.4倍;与样品原液相比,游离氨基酸总量都显著增加（P<0.05）,高压蒸煮处理的样品中含量最高,总质量分数为642.44 mg/100 g。借助偏最小二乘回归方法对样品的感官属性及呈味成分进行相关性分析,发现样品间具有显著性差异（P<0.05）,不同的处理方式所释放的呈味物质分布规律显著不同,高压蒸煮的样品与咸味和鲜味具有显著相关性（P<0.05）;酶解处理的样品与酸味和甜味有较强相关性,其他组样品与感官与呈味属性相关性不强。结论：不同处理方式的金华火腿骨具有不同的风味,其风味特征与多种物质有关,该研究结果为火腿骨的深度开发提供了理论指导,提高金华火腿骨的附加值。     

基于酶抑制法的自助式农药残留检测平台建立

以金华火腿骨为研究对象,研究不同提取方法对其呈味物质释放的影响。通过感官评价及可溶性糖、有机酸、5''-核苷酸和游离氨基酸的测定分析不同处理组间样品的差异,同时采用偏最小二乘回归法（partial least squares regression,PLSR）对提取物感官和呈味物质间进行相关性分析。感官评价发现,高压蒸煮的样品的鲜味、咸味和可接受度最高,其协同滋味的综合评分最佳;呈味物质分析发现,原液中所有呈味物质含量都最低,高压-复配酶解处理的样品中可溶性糖总量最高,高达132.68 mg/100 g;经过酶解处理样品有机酸含量显著增加（P<0.05）,达到3 733.32 mg/100 g;样品经不同处理后,5''-核苷酸含量呈现显著性增加（P<0.05）,总含量最高的是经过高压蒸煮处理的样品,质量分数高达1.24 mg/100 g,是原液和其他处理组样品的2.38～12.4倍;与样品原液相比,游离氨基酸总量都显著增加（P<0.05）,高压蒸煮处理的样品中含量最高,总质量分数为642.44 mg/100 g。借助偏最小二乘回归方法对样品的感官属性及呈味成分进行相关性分析,发现样品间具有显著性差异（P<0.05）,不同的处理方式所释放的呈味物质分布规律显著不同,高压蒸煮的样品与咸味和鲜味具有显著相关性（P<0.05）;酶解处理的样品与酸味和甜味有较强相关性,其他组样品与感官与呈味属性相关性不强。结论：不同处理方式的金华火腿骨具有不同的风味,其风味特征与多种物质有关,该研究结果为火腿骨的深度开发提供了理论指导,提高金华火腿骨的附加值。     

Chloroplast DNA study in sweet cherry cultivars (Prunus avium L.) using PCR-RFLP method

The chloroplast DNA of 96 sweet cherry cultivars (Prunus avium L.) and five cultivars of sour cherry (P. cerasus L.) were analysed to reveal their haplotypes using PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) method. The main advantages of the PCR-RFLP technique are: resolutive, time and cost effective and reproducible. Approximately 9.6% of the chloroplast genome was analysed, using six universal primer pairs and two restriction enzymes. All the mutations detected were insertion-deletions, ranging between 5–30 bp. The combination of all the mutations resulted in three haplotypes (H1, H2 and H3) in the 96 sweet cherry cultivars and a single haplotype (H4) in the five cultivars of sour cherry. The cpDNA polymorphism determined by PCR-RFLP markers helped to understand the maternal inheritance of chloroplast genome in sweet cherry, clearly distinguished the sour from the sweet cherry, and supported that P. avium is not the maternal species of P. cerasus.     

Chemical and sensory quality of processed carrot puree as influenced by stress-induced phenolic compounds

Physicochemical analysis of processed strained product was performed on 10 carrot genotypes grown in Texas (TX) and Georgia (GA). Carrots from GA experienced hail damage during growth, resulting in damage to their tops. Measurements included pH, moisture, soluble phenolics, total carotenoids, sugars, organic acids, and isocoumarin (6-MM). Sensory analysis was conducted using a trained panel to evaluate relationships between chemical and sensory attributes of the genotypes and in carrots spiked with increasing levels of 6-MM. Preharvest stress conditions in GA carrots seemed to elicit a phytoalexic response, producing compounds that impacted the perception of bitter and sour flavors. Spiking 6-MM into strained carrots demonstrated the role bitter compounds have in lowering sweetness scores while increasing the perception of sour flavor. Screening fresh carrots for the phytoalexin 6-MM has the potential to significantly improve the sensory quality of processed products.     

Morphological characterization of sweet and sour cherry cultivars in a germplasm bank at Portugal

Nine sweet cherry and eight sour cherry varieties located in a germplasm bank at Fundão, Portugal, were studied from the viewpoint of characterization. Most of them were autochthonous cultivars that have a high risk of extinction since at the present they are markedly minor varieties. Morphological characteristics were evaluated in different organs: crown and trunk of the trees, leaves, flowers and fruits, over a three consecutive years period. Statistical analyses were carried out in order to detect similarities between cultivars as well as the existence of synonymies. Qualitative characteristics of the fruits were scored in order to carry out the multivariate analysis. A dendrogram of the evaluated characters shows the marked differentiation between sour and sweet cherries and suggests the existing synonymies. Conservation of the autochthonous cultivars in the future is highly recommended.     

不同品种樱桃番茄氨基酸组成及风味分析

为评价不同品种樱桃番茄的风味及营养价值,比较分析了8个品种樱桃番茄的可溶性固形物含量、总糖含量、有机酸含量、糖酸比、Vc含量、氨基酸含量和氨基酸组成。结果表明,红果樱桃番茄品种的部分风味指标(可溶性固形物、总糖、有机酸、Vc)、氨基酸组成及营养价值(总氨基酸、必需氨基酸含量及氨基酸模式谱)优于黄果品种,尤其是红果品种浙樱粉1号和浙樱红1号,其中,浙樱粉1号樱桃番茄可溶性固形物含量、总糖含量、有机酸含量、Vc含量、呈味类氨基酸(鲜味、甜味、芳香类)含量及氨基酸营养价值均处于较高水平。红果樱桃番茄品种之间的总糖含量、Vc含量,以及黄果樱桃番茄品种之间的有机酸含量、总氨基酸含量、必需氨基酸含量和甜味类氨基酸含量等指标均呈现出较低的变异系数。氨基酸营养价值分析表明,缬氨酸和亮氨酸是樱桃番茄的2个主要限制氨基酸。本研究结果为高品质樱桃番茄的品种选育提供了理论指导。     

Relationships of sweet, bitter, and roasted peanut sensory attributes with carbohydrate components in peanuts

Certain roasted peanut quality sensory attributes have been shown to be heritable. Currently the only means of measuring these traits is the use of a trained sensory panel. This is a costly and time-consuming process. It is desirable, from a cost, time, and sample size perspective, to find other methodologies for estimating these traits. Because sweetness is the most heritable trait and it has a significant positive relationship to the roasted peanut trait, the possible relationships between heritable sensory traits and 18 carbohydrate components (inositol, glucose, fructose, sucrose, raffinose, stachyose, and 12 unknown peaks) in raw peanuts from 52 genotypes have been investigated. Previously reported correlations among sweet, bitter, and roasted peanut attributes were evident in this study as well. Where there was positive correlation of total sugars with sweetness, there also was positive correlation of total sugars with roasted peanut attribute and negative correlation of total sugars with bitterness and astringency. The expected generalized relationship of total sugars or sucrose to sweetness could not be established because the relationship was not the same across all market-types. Further work is needed to determine the nature of the chemical components related to the bitter principle, which appear to modify the sweet response and interfere with the sensory perception of sweetness, particularly in the Virginia market-type. Also, certain carbohydrate components showed significant relationships with sensory attributes in one market-type and not another. These differential associations demonstrate the complexity of the interrelationships among sweet, bitter, and roasted peanut sensory attributes. Within two market-types it is possible to improve the efficiency of selection for sweetness and roasted peanut quality by assaying for total carbohydrates. On the basis of the regression values the greatest efficiency would occur in the fastigiate market-type and then the runner.     

Quality assessment of strawberries (Fragaria species)

Several cultivars of strawberries (Fragaria sp.), grown under different conditions, were analyzed by both sensory and instrumental methods. The overall appreciation, as expressed by consumers, was mainly reflected by attributes such as sweetness and aroma. No strong correlation was obtained with odor, acidity, juiciness, or firmness. The sensory quality of strawberries can be assessed with a good level of confidence by measuring the total sugar level ( degrees Brix) and the total amount of volatile compounds. Sorting out samples using the score obtained with a hedonic test (called the "hedonic classification method") allowed the correlation between consumers' appreciation and instrumental data to be considerably strengthened. On the basis of the results obtained, a quality model was proposed. Quantitative GC-FID analyses were performed to determine the major aroma components of strawberries. Methyl butanoate, ethyl butanoate, methyl hexanoate, cis-3-hexenyl acetate, and linalool were identified as the most important compounds for the taste and aroma of strawberries.     

LED红蓝弱光照射保持樱桃番茄冷库贮藏品质

为了探究单色光对番茄冷藏过程中品质的影响,开发樱桃番茄保鲜新技术,以绿熟期樱桃番茄(Lycopersicon esculentum Mill.)为试材,在4℃条件下分别采用发光二极管(LED,light emitting diode)红蓝单色弱光(30 lx)持续照射,研究LED红蓝单色弱光对樱桃番茄采后贮藏过程中感官和主要营养品质指标的影响。结果表明:研制的LED试验装置稳定可靠,红蓝单色光的发射光谱稳定,不因光照强度的变化而发生偏移。贮藏10 d以后LED红蓝光处理的樱桃番茄感官品质显著优于无光对照(P0.05),且LED红光处理好于蓝光处理(P0.05)。LED蓝光照射能较好地保持樱桃番茄维生素C含量(P0.05),但LED红光照射不利于维生素C含量的保持。LED红蓝单色弱光照射有利于促进樱桃番茄早期贮藏过程中的还原糖和可溶性总糖积累,显著抑制贮藏后期糖含量的下降(P0.05)。LED红蓝单色弱光照射处理还能显著延缓樱桃番茄贮藏过程中可溶性固形物下降(P0.05),提高樱桃番茄果实可滴定酸的含量,其中LED红光处理显著高于蓝光处理(P0.05)。贮藏20 d时,红光照射可显著促进番茄红素的合成,但贮藏过程中LED蓝光照射与对照差异不显著(P0.05)。综合来看,与对照(CK)相比,LED红蓝弱光(30 lx)照射有利于樱桃番茄4℃贮藏过程中感官和营养价值的保持,其中LED红色弱光照射处理效果较好。作为一种简便可行的物理保鲜方法,LED红蓝弱光持续照射处理在樱桃番茄采后营养品质调控方面具有应用潜力。     

Categorizing Rice Cultivars Based on Cluster Analysis of Amylose Content,Protein Content and Sensory Attributes

Presently, rice cultivars are categorized according to grain dimensions, amylose content, and alkali spreading value (gelatinization temperature type). Categorization of rice cultivars based on total sensory impact is needed. This work endeavors to divide world rices into groups based on amylose, protein, flavor, and texture properties. Ninety‐one rice samples representing 79 different cultivars and seven growing locations were separated into seven groups with Ward's Cluster Analysis. Cluster 1 included a third of the rice samples and had cultivars with a large diversity of grain shapes and amylose contents. Mean attribute scores for this cluster were near the grand mean for the collective rice samples for nearly every sensory attribute. Cluster 2 included conventional U.S. short‐ and medium‐grain cultivars. Cluster 3 included conventional U.S. medium cultivars that were produced in Louisiana. Mean sensory scores for this cluster characterized these cultivars as having relatively undesirable flavor and texture attributes. Cluster 4 included Japanese premium quality cultivars and U.S. medium‐grain cultivars developed for the Japanese market. Cluster 5 included high‐amylose, indica types that had relatively firm textural properties. Cluster 6 included relatively soft cooking, aromatic cultivars. Cluster 7 included waxy cultivars and other soft cooking grains. In several cases, the production environment (location, weather effects, etc.) influenced flavor and texture characteristics and resulted in the cultivar falling into an unexpected cluster. This categorization serves as a catalyst for indexing rice cultivars for cooking and processing qualities.     

Quality evaluation and prediction of Citrullus lanatus by 1H NMR-based metabolomics and multivariate analysis

(1)H NMR spectrometry in combination with multivariate analysis was considered to provide greater information on quality assessment over an ordinary sensory testing method due to its high reliability and high accuracy. The sensory quality evaluation of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) was carried out by means of (1)H NMR-based metabolomics. Multivariate analyses by partial least-squares projections to latent structures-discrimination analysis (PLS-DA) and PLS-regression offered extensive information for quality differentiation and quality evaluation, respectively. The impact of watermelon and rootstock cultivars on the sensory qualities of watermelon was determined on the basis of (1)H NMR metabolic fingerprinting and profiling. The significant metabolites contributing to the discrimination were also identified. A multivariate calibration model was successfully constructed by PLS-regression with extremely high reliability and accuracy. Thus, (1)H NMR-based metabolomics with multivariate analysis was considered to be one of the most suitable complementary techniques that could be applied to assess and predict the sensory quality of watermelons and other horticultural plants.     

Postharvest treatments with salicylic acid, acetylsalicylic acid or oxalic acid delayed ripening and enhanced bioactive compounds and antioxidant capacity in sweet cherry

Sweet cherry cultivars ('Cristalina' and 'Prime Giant') harvested at commercial ripening stage were treated with salicylic acid (SA), acetylsalicylic acid (ASA) or oxalic acid (OA) at 1 mM and then stored for 20 days under cold temperature. Results showed that all treatments delayed the postharvest ripening process, manifested by lower acidity, color changes and firmness losses, and maintained quality attributes for longer periods than controls. In addition, total phenolics, anthocyanins and antioxidant activity increased in untreated fruit during the first 10 days of storage and then decreased, while in fruits of all treatments, these parameters increased continuously during storage without significant differences among treatments. Thus, postharvest treatments with natural compounds, such as SA, ASA or OA, could be innovative tools to extend the storability of sweet cherry with higher content of bioactive compounds and antioxidant activity as compared with control fruits.     

Biochemical and genomic analysis of neoculin compared to monocot mannose-binding lectins

Neoculin occurring in an edible tropical fruit is a heterodimeric protein which has both sweetness and a taste-modifying activity that converts sourness to sweetness. Both the primary and the overall tertiary structures of neoculin resemble those of monocot mannose-binding lectins. This study investigated differences in biochemical properties between neoculin and the lectins. Structural comparison between the mannose-binding sites of lectins and the corresponding regions of neoculin showed that there is at least one amino acid substitution at each site in neoculin, suggesting a reason for the lack of its mannose-binding ability. This was consistent with hemagglutination assay data demonstrating that neoculin had no detectable agglutinin activity. DNA microarray analysis indicated that neoculin had no significant influence on gene expression in Caco-2 cell, whereas kidney bean lectin (Phaseolus vulgaris agglutinin) greatly influenced various gene expressions. These data strongly suggest that neoculin has no lectin-like properties, encouraging its practical use in the food industry.     

Volatile flavor analysis and sensory evaluation of custard desserts varying in type and concentration of carboxymethyl cellulose

The influence of type and concentration of carboxymethyl cellulose (CMC) on flavor and textural properties of custard desserts was examined. A synthetic strawberry flavor mixture was used to flavor the custards; it comprised 15 volatile flavor compounds. The viscosity of the custards was determined using rheometric measurements. Static headspace gas chromatography and in-nose proton transfer reaction-mass spectrometry analyses were conducted to determine the custards' volatile flavor properties. Perceived odor, flavor, and textural properties were assessed in sensory analysis experiments using magnitude estimation against a fixed modulus. Both type and concentration of CMC altered the viscosity of the custards. Softer custards had higher static headspace flavor concentrations. On the contrary, firmer custards demonstrated higher in-nose flavor concentrations. In sensory analysis, firmer custards showed higher thickness and lower sweetness intensities than their low-viscosity counterparts. The thickness perception corresponded to the viscosity of the custards. Removal of sucrose from the custards affected sweetness intensity only and not the intensity of other attributes. Therefore, the influence of the viscosity of the custards on the release of sweet-tasting components is held responsible for the effect on perceived sweetness intensity. Odor intensities were generally higher for the low-viscosity custard, whereas fruity flavor intensities were higher for the firmer custards. Odor intensities correlated with static headspace concentrations and flavor intensities related reasonably well with in-nose concentrations. Opening and closing of the nasal cavity is regarded as an important factor determining the discrepancy between static and in-nose measurements.     

Investigation of different apple cultivars by high resolution magic angle spinning NMR. A feasibility study

(1)H HR-MAS NMR spectroscopy was applied to apple tissue samples deriving from 3 different cultivars. The NMR data were statistically evaluated by analysis of variance (ANOVA), principal component analysis (PCA), and partial least-squares-discriminant analysis (PLS-DA). The intra-apple variability of the compounds was found to be significantly lower than the inter-apple variability within one cultivar. A clear separation of the three different apple cultivars could be obtained by multivariate analysis. Direct comparison of the NMR spectra obtained from apple tissue (with HR-MAS) and juice (with liquid-state HR NMR) showed distinct differences in some metabolites, which are probably due to changes induced by juice preparation. This preliminary study demonstrates the feasibility of (1)H HR-MAS NMR in combination with multivariate analysis as a tool for future chemometric studies applied to intact fruit tissues, e.g. for investigating compositional changes due to physiological disorders, specific growth or storage conditions.