“Chilled” pork—Part I: Sensory and physico-chemical quality

Chilled meat exportation comprises chilling within 48 h post-mortem to temperatures < 0 °C without freezing and holding under these conditions for several weeks. The effects of this ageing on sensory quality of pork are unknown and hence the objective of this study was to compare the sensory quality of Canadian pork as found in an export (Japan) market and locally. Regardless that the Japanese market's quality criteria were met, pork sorted on-line differed (P < 0.05) from that for the domestic market only for lightness, exudate and cooking loss; no differences in intramuscular fat content were observed. Overall, a trained panel scored weaker pork and meat flavours and odours in the export than the domestic pork as a result of either the quality by selection if roasted or the ageing (− 1.7 °C, 43 days exported chilled or 3.1 °C, 5 days domestic) if grilled or shabu shabu. Grilled pork was also more tender, sweeter and had stronger caramel flavour with the chilled ageing.     

Consumer perception of ice cream and frozen desserts in the “better-for-you” category

The consumption of ice cream and frozen desserts in the “better-for-you” (BFY) category has grown rapidly over the past few years, even as traditional ice cream sales remain stagnant. To better understand consumer preferences within the BFY category, an online survey (n = 1,051) was conducted with ice cream and frozen dessert consumers, followed by consumer acceptance testing of commercial BFY frozen dairy desserts. Consumers of BFY frozen desserts (n = 578) completed an adaptive choice-based conjoint survey and MaxDiff exercise to identify the attributes that drive purchase of BFY frozen desserts. MaxDiff exercises were also used to determine which attributes all frozen dessert consumers (n = 1,051) perceived to make a frozen dessert BFY and which stabilizers or emulsifiers were most attractive on an ice cream or frozen dessert label. Subsequently, a consumer acceptance test (n = 186) was conducted using 4 commercial vanilla-flavored frozen dairy desserts made with different sweetening systems (sugar, sucralose + acesulfame K, monk fruit + allulose, and stevia + erythritol). Half of consumers were primed or informed with the sweeteners and basic nutritional information for the frozen desserts before tasting, and the other half of consumers evaluated samples blinded, where they were only informed that they were tasting a vanilla-flavored frozen dessert. Sweetener type and base (dairy vs. plant) were the most important attributes to BFY consumers when selecting a BFY frozen dessert (n = 578). For all ice cream and BFY dessert consumers (n = 1,051), sweetener-related claims (naturally sweetened, reduced sugar, no added sugar), along with “all natural” and a short ingredient list, were the top attributes that contributed to perception of a “healthier” frozen dessert. When BFY frozen desserts were tasted by consumers, purchase intent decreased after tasting, suggesting that frozen desserts made with natural non-nutritive sweeteners did not meet consumer expectations. Flavor of BFY frozen desserts remains more important than perceived healthiness. Consumers perceive frozen desserts, even those in the BFY category, as an indulgence. Frozen dessert manufacturers should focus on naturally sweetened, dairy-based desserts with minimal sweetener-related flavor defects when designing products for the BFY category.     

The role of production method information on sensory perception of smoked salmon—A mixed-method study from Denmark

Product information is capable of steering the consumers’ expectation formation process. Therefore, this paper aims to investigate whether information on production method influence consumers’ preference and liking of smoked salmon. A consumer test was conducted among 92 consumers to determine liking of the smoked salmon on a 7-point hedonic scale before (blind) and after (informed) receiving information about production method (organic, conventional and wild-caught). Further, two explanatory focus group discussions (n = 5 in each group) were conducted to determine consumers’ belief on production method.A linear mixed-effects model analysis indicated that the consumer overall liking of wild-caught smoked salmon significantly increased after production method information was provided, while regarding organic and conventional smoked salmon no significant difference was noted. Post hoc test indicated that organic smoked salmon was significantly more liked than wild-caught smoked salmon (mean difference ± standard error: 0.652 ± 0.19, p < 0.01) in blind condition, however, between organic and conventional smoked salmon no significant difference was noted (-0.032 ± 0.19, p = 0.983). Further, in informed condition, organic smoked salmon was significantly more liked than conventional smoked salmon (0.50 ± 0.19, p < 0.05), however, between organic and wild-caught smoked salmon no significant difference was noted (0.228 ± 0.19, p = 0.452). Relative importance analysis results suggest that liking of taste was the most important contributor (26.84%) to smoked salmon overall liking (p < 0.05, R² = 74.17%). Focus group discussion revealed that consumer beliefs related to food safety, animal welfare and sustainability as well as purchasing habits seem to influence smoked salmon preferences.Thus, organic aquaculture sector should focus on promoting consumer beliefs by providing reliable information based on scientific evidences that helps differentiates their products with that of conventional and wild-caught smoked salmon. Future studies might investigate other fish species to better understand the role of product method information on consumer preference and liking of fish.     

Effect of γ-irradiation on the sensory quality of moist beef biltong

Moist beef biltong (mean moisture content = 46.7% and a_w = 0.919) was vacuum packaged and irradiated to target doses of 0, 2, 4, 6, and 8 kGy. Thiobarbituric acid reactive substance (TBARS) measurements and sensory difference and hedonic tests were performed to determine the effect of γ-irradiation on the sensory quality of the biltong. TBARS values only increased significantly (P < 0.05) if biltong was irradiated to at least 8 kGy, indicating a low degree of lipid oxidation. This can be attributed to the low fat content (on average 1.53%) of the biltong used in this study, as well as irradiation under vacuum conditions. All irradiated samples could be discriminated (P < 0.05) from non-irradiated biltong, but none was rated as less acceptable. Dissipation of volatiles before tasting (by exposing the product to aerobic conditions before consumption), a low degree of lipid oxidation and liking of distinct ‘irradiation flavours’ possibly all attributed to the flavour of irradiated biltong not being regarded as unacceptable compared to controls. Biltong irradiated at 2 and 4 kGy was however liked significantly more (P < 0.05) than other samples, indicating that slight, non-oxidative irradiation-induced flavour changes may contribute to flavour development in the usually more bland moist beef biltong. Although lean moist beef biltong can thus be irradiated to doses up to 8 kGy without adversely affecting the sensory acceptability, low dose irradiation (4 kGy) is most feasible to optimise the sensory quality.     

Quality evaluation of pickling cucumbers using hyperspectral reflectance and transmittance imaging—Part II. Performance of a prototype

This paper reports on the development and evaluation of methods and algorithms for detecting both external and internal quality of pickling cucumbers using the hyperspectral reflectance and transmittance images acquired by an online prototype described in a previous paper [1]. Experiments were performed in 2 years on ‘Journey’ pickling cucumbers, some of which were subjected to mechanical stress to induce internal defect in seed cavity. Hyperspectral images of the ‘Journey’ pickling cucumbers were collected under reflectance, transmittance, and their combination modes. Partial least squares analysis was performed on spectra extracted from the hyperspectral images to predict firmness, color, and the presence of internal defect. The system performed well on predicting skin color (chroma and hue) with the coefficient of determination (R ²) ranging between 0.75 and 0.77; however, it had poor prediction of fruit firmness. Transmittance data in the spectral region of 675–1,000 nm provided the best detection of internal defect for the test pickling cucumbers, with the detection accuracy up to 99%. Up to the best four wavelength combinations were identified using linear discriminant analysis for internal defect detection. The hyperspectral imaging technique can be used for simultaneous detection of color, size, and internal defect on pickling cucumbers.     

Effect of replacing pork backfat with pre-emulsified olive oil on lipid fraction and sensory quality of Chorizo de Pamplona - a traditional Spanish fermented sausage

Six treatments of Chorizo de Pamplona, traditional Spanish fermented sausage, were manufactured under usual commercial conditions by replacing 0, 10, 15, 20, 25 and 30% of pork backfat by pre-emulsified olive oil with soy protein isolate. Sausages with 20-30% replacing level had higher (P<0.05) protein content than control as a result of the addition of soy protein isolate. The oleic acid increased (P<0.05) in sausages with 15-30% replacing level, and linoleic acid increased in sausages with 10-25%. Sausages with 10-25% of substitution had lower total SFA-stearic and higher (P<0.05) total MUFA, total PUFA, (MUFA+PUFA)/(SFA-stearic), and PUFA/(SFA-stearic). Cholesterol content showed reduction about 12-13% in sausages with 20-25% replacing level, and up to 22% in sausages with 30% replacing level. Sausages with 10-25% of substitution were acceptable from the sensorial point of view. The texture and colour instrumental measures were comparable with that of commercial products. No increments in hexanal content were observed. It is concluded that up to 25% of pork backfat can be replaced with pre-emulsified olive oil in the production of Chorizo de Pamplona fermented sausages. Higher replacing levels of pork backfat did not show nutritional advantages in relation to the fatty acid profile and were unacceptable due to considerable dripping of fat during ripening.     

Expected effects on carcass and pork quality when surgical castration is omitted — Results of a meta-analysis study

Alternatives to the common castration (C) practice of piglets are surgical castration under anaesthesia and rearing entire males (EM) or immunocastrates (IC). It is well established that boar taint hinders the breakthrough of these options. Less is known how avoiding surgical castration would affect carcass characteristics and pork quality. The objective of this meta-analysis was to estimate the impact of lack of castration on quality traits besides boar taint. The most marked effect of castration method and gender was found in lean meat and intramuscular fat percentage. Compared to EM, carcass leanness was estimated to be greater (P < 0.05) and intramuscular fat level lower (P < 0.05) than in C, IC and females. Regarding pork quality traits only the difference in shear force between IC and EM was of relevant magnitude. This meta-analysis revealed that the implementation of EM production should not be hindered by pork quality concerns.     

Extrinsic and intrinsic quality cues in Chinese consumers’ purchase of pork ribs

Due to the ongoing changes from traditional open markets to Western style supermarkets in China, Chinese consumers have the opportunity to base their decisions increasingly on extrinsic quality cues like brand, safety certification and origin, in addition to the traditional intrinsic quality cues like color and fat. This study investigates choice of fresh pork by Chinese consumers employing a pairwise choice methodology. Latent class analysis shows that for the majority of consumers intrinsic cues are still dominating the choice, and only for a small segment did information on brand, origin and quality certification have a major role. Also, there was a segment of consumers that did seem to make random choices. The results indicate that Chinese consumers are still in a transitory phase, where they are building up competencies in handling product information while the sector struggles to build credibility and trust.     

A Review on Natural Fibre-Based Composites—Part II

Abstract

Natural abundance, much higher strength per unit weight than most inorganic fillers, lower density and their biodegradable nature make natural fillers attractive as reinforcements of engineering polymer systems. However, certain drawbacks such as incompatibility with the hydrophobic polymer matrix, the tendency to form aggregates during processing and poor resistance to moisture greatly reduce the potential of natural fibres to be used as reinforcements in polymers. In this review, the main results presented in literature are summarized, focusing on the processing behaviour and final properties of natural fibres with polymeric matrices (thermoplastics, thermosets and biodegradables) and paying attention to the use of physical and chemical treatments for the improvement of fibre-matrix interaction and composite mechanicaln properties. This work mainly focuses on the use of natural fibres for automotive applications.     

How do culinary methods affect quality and oral processing characteristics of pork ham?

The influences of three different culinary methods: cooking, sous vide and grilling were studied with regards to quality and oral processing characteristics of pork ham. Besides instrumental analysis of color and textural properties of pork ham, sensory panel with 12 trained panelists participated in temporal dominance of sensations, oral processing analysis, boluses collection, particle size distribution analysis, and saliva incorporation. The results revealed that number of chews, mastication time and saliva incorporation are correlated with textural properties and cooking losses. In‐mouth sensation was intertwined with juiciness, fibrousness and firmness depending on the culinary methods. Cooked pork ham showed highest results for hardness and cooking loss. Firmness and fibrousness were dominant sensory attributes. Sous‐vide results show that firmness and juiciness dominated during the first third of consumption time. This corresponds with textural values for lowest values for hardness and cooking, number of chews and total exposure time. Sous‐vide also resulted in lower values for number of chews and total exposure time associated with oral processing.     

Consumer perception of dried dairy ingredients: Healthy,natural, and sustainable?

Conscious consumerism is growing, along with consumer demand for socially conscious dairy products or dairy alternatives. To successfully position dairy products (especially conventional dairy) in this changing marketplace, dairy producers and processors must understand how to strategically use both on- and off-package messaging aligned with consumer perceptions. However, consumer perception of attributes such as sustainable, natural, and healthy is complex, and varies between product categories as well as among products within a category. The objective of this study was to characterize consumer definitions of the terms “sustainable,” “natural,” and “healthy” as they pertain to dried dairy ingredients. To meet this objective, we conducted an online survey with 3 maximum difference scaling exercises to determine the importance of 63 label claims to consumer definitions of the terms sustainable, natural, and healthy. The role of priming with dried ingredient processing information on consumer perception of these terms was also explored. Within the dried dairy ingredients category, there is extensive cognitive overlap between the terms sustainable, natural, and healthy. Priming did not affect consumer definitions of any of these terms. Certification-related claims were considered among the least important claims for consumer definitions of sustainable, natural, and healthy, whereas claims that were simple to read and visualize were considered among the most important. Claims related to animal welfare and happiness or simple, minimal ingredients and processing were considered by consumers to be important for all 3 terms. For each of these terms, there was a cluster of consumers who defined the term primarily by simple ingredients and minimal processing, and another cluster who defined the term primarily by happy cows and conscious farming practices. The terms sustainable and healthy each had a third, unique consumer cluster. This third definition cluster defined sustainability primarily by environmental effects, whereas this cluster defined healthy primarily in fitness and nutrition terms. Age and to a lesser extent, gender, affected importance placed on these 3 terms and also affected definition of the term. Understanding these consumer definitions provides insight on how to formulate marketing and educational messaging to speak to each consumer segment.     

Use of Lactococcus lactis subsp. cremoris NCDO 763 and α-ketoglutarate to improve the sensory quality of dry fermented sausages

The aim of the present work was to enhance the degradation of free amino acids in dry fermented sausages as precursors of volatile compounds responsible for the ripened flavour. For this purpose, Lactococcus lactis subsp. cremoris NCDO 763, its intracellular cell free extract (ICFE) and α-ketoglutarate were added to sausages. Papain was also used to increase the amount of free amino acids. When L. lactis was inoculated in sausages, an increase in the proteolytic phenomena was observed. The addition of α-ketoglutarate increased transamination phenomena in batches where it was added. The enhancement of these phenomena determined a noticeable rise in the content of glutamic acid (the main final product in transamination reactions) and a decrease, among other amino acids, of valine and leucine, with the formation of high amounts of their derivatives 2-methylpropanal and 3-methylbutanal. These aldehydes are responsible for the ripened flavour of dry fermented sausages. Sensory analysis showed an improvement of odour and flavour when L. lactis and α-ketoglutarate were combined. On the other hand, the intracellular cell free extract of L. lactis did not show any important activity in relation to amino acid breakdown even when used together with α-ketoglutarate and/or papain.     

Characterization of traditional and exotic apple varieties from Portugal. Part 1 – Nutritional,phytochemical and sensory evaluation

Phytochemical and nutritional characterization of traditional (Bravo de Esmolfe, Malápio Fino, Malápio da Serra, and Pêro Pipo) and exotic (Golden, Starking, Fuji, Reineta Parda and Gala Galaxy) apple varieties from Portugal were performed. Measurements were taken on 43 parameters including water, protein, sugars, acids, fibre, vitamins (C, A,B1, B2, B3, B5, B6, B9, β-carotene and α-tocopherol), minerals (K, P, Mg, Ca, S, Na, Si, B, Fe, Al, Cu, Mn, Zn, Ni, Mo, Cd) and polyphenols (total, catechin, epicatechin, chlorogenic acid, phloridzin, quercetin-3-glucoside, quercetin-3-rhamnoside, kaempferol-3-glucoside, procyanidins B1 and B2). Nutritional composition results showed that traditional apples had higher contents of fibre, protein, sugars, β-carotene, vitamin E, Mg and phenolic compounds. A comparison between unpeeled and peeled apples was also performed for the Bravo de Esmolfe variety and the unpeeled apples had higher amounts of fibre. Results from sensory evaluation of traditional apples performed by selected assessors and consumers showed there were differences among sample attributes such as sourness, juiciness and hardness, and two apple varieties were preferred (Bravo de Esmolfe and Pêro Pipo) for their odour, taste, hardness and juiciness.     

Effects of dietary α-linolenic acid on the fatty acid composition, storage stability and sensory characteristics of pork loin

Effects of dietary α-linolenic acid on the fatty acid composition, storage stability and sensory characteristics of cooked pork were studied. Dietary α-linolenic acid (LNA) significantly (p < 0.05) increased the proportion of n−3 fatty acids and the degree of unsaturation in the neutral lipids and phospholipids. The increases in n−3 fatty acids were observed in the total lipids, triglycerides, phosphatidylethanolamine and phosphatidylcholine, and mainly consisted of C18:3n3, C20:5n3 and/or C22:5n3.The thiobarbituric acid reactive substances (TBARS) values (mg malondialdehyde per kg meat) of cooked vacuum packaged loins remained below 1.5, but in loose packaged loins TBARS values increased more than 3 times those of 0 time values during 2-day storage at 4 °C. The TBARS values of loins after LNA-enrichment were significantly higher than those of the control in both vacuum and loose packaging, and the increase of unsaturation in fatty acids had a strong prooxidant effect. The increase in dietary LNA enrichment increased oxidation (TBARS values) and had a detrimental effect on the acceptability of cooked pork loins held for 2 days in loose packaging.     

Effects of nutritional level on pork quality and gene expression of μ-calpain and calpastatin in muscle of finishing pigs

The study was designed to investigate the effects of nutritional level (control diet (CD), 14.19% crude protein, 13.81 MJ of DE/kg; low nutritional level diet (LND), 11.08% crude protein, 12.55 MJ of DE/kg) on pork quality and gene expression of μ-calpain and calpastatin in muscle of finishing pigs. The LND treatment increased drip loss (P < 0.05), had a trend to increase intramuscular fat (IMF) content (P = 0.09), decreased Warner–Bratzler shear force (WBSF) of pork (P < 0.05), improved mRNA level of μ-calpain (P < 0.05) in skeletal muscle, but had no effect on gene expression of calpastatin, compared with the CD treatment. These data suggest that a moderately reduced energy and protein diet increased pork tenderness and intramuscular fat. The increase in tenderness by LND treatment may be partly due to increased gene expression of μ-calpain in muscle.     

Investigation of Combing Forces. Part IV: Disentangling Twisted Fibres—Evaluation

The model evaluated in this paper represents the first attempt at theoretically investigating the critical pin speed in combing, below which breakage of twisted fibres might be avoided. The theoretical model requires several assumptions about the geometry of the twisted fibres. Various empirical curves obtained in this paper by using nylon 6 filament to simulate the twisted fibres show general agreement with those predicted by the postulated model.