STEROL, PHOSPHOLIPID, MINERAL CONTENT AND PROXIMATE COMPOSITION OF FILETS OF SELECT FRESHWATER FISH SPECIES

This paper tabulates the sterol, phospholipid, mineral content and the proximate composition of fifteen species of freshwater fish [Bass, Rock (Ambloplites rupestris); Bass, White (Morone chrysops); Bullhead, Brown (Ictalurus nebulosus); Burbot (Lota lota); Carp (Cyprinus carpio); Crappie, Black (Pomoxis nigromaculatus); Drum, Freshwater (Aplodinotus grunniens); Perch, White (Morone americanus); Perch, Yellow (Perca flavescens); Pike, Northern (Esox lucius); Pike, Walleye (Stizostedion vitreum); Smelt, American (Osmerus mordax); Sucker, White (Catostomus commersonni); Sunfish, Pumpkinseed (Lepomis gibbosus); Trout, Brook (Salvelinus fontinalis); Trout, Lake (Salvelinus namaycush); Trout, Rainbow (Salmo gairdneri)]. The fish contained an average 78, 19 and 1.1 percent moisture, protein and ash, respectively. Potassium, phosphorus and calcium averaging 400, 200 and 100 mg/100 g filet were the predominant mineral components. The lipid contents of filets ranged from 0.7 for rock bass to 7.2 for lake trout with most species averaging around 2.0% lipid. Phospholipids ranged from 185 to 875 mg/100 g filet and showed an inverse relationship to the total lipids. Cholesterol was the only sterol present and averaged 70 mg/100 g filet. Cholesterol showed a weak correlation with protein content of filet.     

IMPROVEMENT OF OXIDATIVE STABILITY OF ROASTED PEANUTS BY EDIBLE COATINGS AND ULTRASONICATION

In this study, an innovative method was developed to improve the shelf life of roasted peanuts. Sonication was combined with edible coating for enhancing the oxidative stability of roasted peanuts. Georgia green runner peanuts were roasted, subjected to sonication and then coated with whey protein isolate (WPI), ZEIN and carboxymethyl cellulose (CMC). Relative to the control, the oxidative stability of roasted-coated samples was improved by 80, 38 and 5% for CMC, WPI and ZEIN coating, respectively, while roasted-sonicated-coated samples were improved by 91, 52 and 27% for CMC, WPI and ZEIN coating, respectively. Sonication prior to coating resulted in 11, 14 and 22% improvement beyond the CMC, WPI and ZEIN coatings, respectively. Texture analysis showed there were no significant differences ( P <  0.05) in peanut texture between the treated and the control. Color results showed the HunterLab color parameters L, a, and b for most of the treatments did not have significant differences ( P <  0.05) compared with the control.

PRACTICAL APPLICATIONS

Edible coatings used in this study (carboxymethyl cellulose, whey protein isolate and ZEIN) were capable of acting as oxygen barriers to reduce peanut lipid rancidity. This research demonstrated the potential of power ultrasound to remove lipids from the peanut surfaces and improve coating adhesion. The texture and the color of coated peanuts did not change over the storage period. This study indicated that edible coatings in combination with sonication provided an alternative way for improving the oxidative stability and eventually the shelf life and quality of roasted peanuts.     

EFFECTS OF WATER STRESS ON THE PROXIMATE COMPOSITION AND MINERAL CONTENTS OF SEEDS OF TWO LUPINS (LUPINUS ALBUS AND LUPINUS MUTABILIS)

Because mineral composition data for lupins subjected to water stress (ws) are incomplete, it is essential to analyze those seeds in order to assess the quality of potential food source for both human and animal nutrition. So, we have performed chemical proximate analysis and determined the mineral profile of seeds from two lupins subjected to ws period and compared with seeds from well‐watered (ww) plants. From the above results we can conclude that the values obtained fall within the range of values reported for both species (at ww conditions) and no significant (P > 0.05) differences were found in nutritional composition and mineral content between both lupins. Ws period was responsible for a significant increase in sugar, ash, both macroelements (Ca, Na, K, Mg) and microelements (Fe, Zn, Mn, Cu) as well as phytate content. The results obtained are relevant for selection of better mineral nutritive value of seeds from lupin species.     

BELLY THICKNESS EFFECTS ON THE PROXIMATE COMPOSITION, PROCESSING, AND SENSORY CHARACTERISTICS OF BACON

This study was conducted to evaluate the effects of belly thickness on processing, sensory and visual characteristics, moisture and fat of bacon made from 45 bellies of various thicknesses. Belly thickness had a linear effect (P < 0.05) on raw, cured, and cooked weights, and water and fat content. A linear relationship (P < 0.05) was observed between belly thickness and slice integrity, appearance, and lean-to-fat ratio of bacon. Saltiness, texture and mouthfeel, bacon flavor intensity, and off-flavor intensity were unrelated to raw belly thickness.     

SEASONAL CHANGES IN PROXIMATE COMPOSITION OF ANCHOVY AND STORAGE STABILITY OF ANCHOVY OIL

Changes in proximate composition of anchovy were investigated during the catching season from October to March. In addition, stability of anchovy oil depending on storage temperature and time were studied. During the recent study, water, fat, protein and ash content of anchovy varied between 65.9–74.0%, 9.0–15.3%, 12.8–16.4% and 1.7–2.2%, respectively. The anchovy oil stored at 4C was found to be unacceptable for consumption at the end of the 90th day of storage according to peroxide, acid, unsaponifiable matter and thiobarbituric acid values. An identical sample stored at − 18C was acceptable for 120 days of storage, but eventually became unacceptable after that.

PRACTICAL APLICATIONS

Anchovy has a great economic importance for the Turkish fishery industry. Approximately 42% of the annual catch of anchovy is used in fish meal and oil production in Turkey ( SIS 2002 ). Therefore, the proximate composition of anchovy and seasonal changes have fundamental importance for consumers, manufacturers and wholesalers, because it is important for consumers to know what they eat, for manufacturers to figure out how they manage long storage stability for their products, and for wholesalers to buy equivalent of their payment. An important issue that has attracted attention of the manufacturers is the storage life of fish oil. Therefore, the results presented in this study are expected to be useful for the fish oil industry in Turkey or even in other countries processing anchovy into fish oil.